Scientists explore complex metal-support interactions under redox conditions using our Climate system

Scientists explore complex metal-support interactions under redox conditions using our Climate system

Via the DENSsolutions Climate system, a team of scientists uncover the dynamic interplay between platinum nanoparticles and titania support under reaction conditions.

Original article by H. Frey, A. Beck, X. Huang, J.A. van Bokhoven and M. G. Willinger

For catalysts consisting of metal nanoparticles and an oxide support, understanding the synergistic reactions between the metal and support is paramount. In the case of reducible supports, the so-called strong metal-support interaction (SMSI) provides a means of tuning the chemisorption and catalytic properties of supported metal particles. SMSI involves the encapsulation of nanoparticles by a thin layer of partially reduced support material. The encapsulation is typically induced during high-temperature reductive “activation”, i.e., treatment in hydrogen. Notably, the direct imaging of this encapsulated state has mostly been achieved ex situ. Little is known about SMSI under catalytic working conditions, where the application of in situ electron microscopy is invaluable. While environmental transmission electron microscopy (TEM) is generally limited to chamber pressures of around 20 mbar, the DENSsolutions Climate Nano-Reactor can handle pressures 100 times higher, unlocking unprecedented research possibilities for the study of catalysts in their native environment.

In recent research performed at ScopeM, ETH Zurich, where our advanced Climate G+ system is installed, Hannes Frey, Arik Beck, Dr. Xing Huang, Prof. Dr. Jeroen Anton van Bokhoven and Prof. Dr. Marc Georg Willinger investigated the dynamic interplay between metal nanoparticles and oxide support under reaction conditions. More specifically, the scientists revealed the working state of a model catalyst, Pt–TiO, by directly observing the synergistic interactions related to SMSI between the platinum nanoparticles and titania support.

Switching to a redox-active H₂–O₂ mixture

Frey and his fellow collaborators first induced the classical SMSI state by heating the titania-supported platinum nanoparticles (NPs) in H₂. The nanoparticles were then transferred into an O₂ atmosphere via inert gas purging. Interestingly, this treatment resulted in the platinum NPs incurring a nonclassical oxidized SMSI state. After preparing the system, the researchers then exposed it to a redox active atmosphere through the addition of H₂ into the O₂ flow. With the Climate G+ system, the researchers were able to mix the gasses on the fly, while continuing with the high-resolution observation. 

In Figure 1 and Movie 1 below, the morphological change of the platinum NPs upon transition into the redox-active regime is presented. Increasing the partial pressure of H₂ in the Climate Nano-Reactor resulted in the gradual change in the encapsulated state of the Pt NPs. Moreover, this resulted in the ultimate disappearance of the overlayer as soon as the gas composition reached a set mixture of 60 mbar H₂ and 700 mbar O₂ after ~180 s. Once the overlayer was fully removed, the particle was observed to experience particle dynamics like restructuring and migration (shown in Figure 1E and 1F). 

Figure 1: Image series depicting the morphological changes observed when a titania-supported platinum nanoparticle in a nonclassical SMSI state is exposed to a redox-active atmosphere. The composition of the gas in the Nano-Reactor was gradually changed from 700 mbar O₂ to a mixture of 60 mbar H₂ plus 700 mbar O₂. t0 is the time at which the H₂ flow was turned on.

Movie 1: TEM Movie depicting the morphological changes observed when a titania-supported platinum nanoparticle in a nonclassical SMSI state is exposed to a redox-active atmosphere.

Particle and interfacial dynamics in the redox-active regime

The researchers then set out to explore the response of a collection of nanoparticles to reaction conditions. They discovered that the degree of structural dynamics and mobility differed greatly among the nanoparticles. Whereas some NPs remained static and stationary, others incurred structural fluctuations and migrated across the substrate surface. The researchers decided to follow three representative cases of nanoparticles with different orientations. In all cases, it is observed that the redox chemistry at the interface is the driving force for particle reconstruction and migration. In Figure 2 below, the respective structural dynamics of the three selected nanoparticles are presented.

Figure 2: (A–C) Pt NP oriented with (111) planes perpendicular to the interface. (G to J) Pt NP oriented with (111) planes parallel to the interface. (K to N) Pt NP that has its (111) planes inclined toward the interface. The blue shapes indicate the respective positions of the Pt NP in the previous frames.

Case 1

The first platinum NP that was considered was oriented with (111) planes perpendicular to the interface. In Movie 2 below, the recorded time series of this platinum NP at 600°C in an atmosphere containing 700 mbar O₂ plus 60 mbar H₂ is shown. Here, the NP developed pronounced structural dynamics that involved twin formation and shearing along (111) planes in an up-down motion, perpendicular to the interface. 

Movie 2: Recorded time series of the Pt NP presented in Figure 2A–C) at 600°C in an atmosphere containing 700 mbar O₂ plus 60 mbar H₂.

Case 2

The second Pt NP that was considered was oriented with (111) planes parallel to the interface. Movie 3 below shows the image series acquired for this nanoparticle, at 600°C in an atmosphere containing 700 mbar O₂ plus 60 mbar H₂. Here, a continuous step flow motion of the (111)-type facet in contact with the interface is observed.

Movie 3: Image series of the Pt NP presented in Figure 2G–J) at 600°C in an atmosphere containing 700 mbar O₂ plus 60 mbar H₂.

Case 3

The third platinum NP that was considered was oriented with (111) planes inclined towards the interface. Movie 4 below shows the image series acquired for this nanoparticle, at 600°C in an atmosphere containing 700 mbar O₂ plus 60 mbar H₂. In this case, the nanoparticle is observed to engage in redox chemistry-driven directional surface migration which is caused by restructuring at the interface.

Movie 4: Image series of the Pt NP presented in Figure 2K–N) at 600°C in an atmosphere containing 700 mbar O₂ plus 60 mbar H₂.

Retraction of H₂ and reformation of the oxidic SMSI overlayer

The next step for Frey and his fellow researchers was to switch the gas composition from a reactive feed back to a purely oxidizing environment by turning off the H₂ flow. This change in the gas composition resulted in the encapsulated state of the platinum NPs to be reestablished. In Figure 3 below, the morphological change of a Pt NP upon switching the gas from a redox-active environment to a purely oxidizing environment is presented. This switching of the gas composition led to the reformation of a classical particle overgrowth. It is seen that the nanoparticles first adopted a spherical morphology (Figure 3A–C). Then, as soon as H₂ was fully removed from the Nano-Reactor, the support material migrated onto the Pt NPs and the overlayer reformed (Figure 3D–F).

Figure 3: Image series depicting the morphological changes of a Pt NP observed when switching from a redox-active to purely oxidizing environment at 600°C. t0 is the time at which the H₂ flow was set to zero.

Conclusion

The aim of this paper was to reveal the working state of a catalyst via direct observation and to study possible synergistic interactions related to SMSI between metal nanoparticles and a reducible oxide support. The use of our Climate system enabled the researchers to capture in exceptional detail the dynamic and complex metal-support interactions of Pt–TiO₂ under reactive catalytic conditions. This is especially thanks to the advanced capacity of the system to handle pressures of up to 2 bar. 

A key finding of this paper is that the stable configurations of static Pt particles exhibiting encapsulation were observed to exist either in pure H₂ (the classical SMSI state) or in pure O₂ (the nonclassical SMSI state), but not in an environment where both gases were simultaneously present. Indeed, the exposure to the redox-active environment led to the removal of the overlayer and the subsequent emergence of pronounced particle dynamics. Moreover, the in situ observations show that the particle restructuring and migration behavior is dependent on the relative orientation of the particle on the support, and therefore the configuration of the interface. Overall, these findings advance our comprehension of SMSI-induced encapsulation of metal nanoparticles, which can in turn help us better tune the chemisorption and catalytic properties of catalysts. 

Hanglong Wu portrait

“The DENSsolutions Climate System allows us to reveal the so-far unseen: Looking at not only how the gas-phase is changed in the presence of a catalyst, but also studying how the interaction between gas-phase and catalyst leads to the emergence of catalytic function. Direct real-space observation is essential for our understanding of working catalysts and the development of new processes that are urgently needed in view of climate change and limited natural resources.”

Prof. Dr. Marc-Georg Willinger
Professor  |  Technical University of Munich

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Hydrogen vs. syngas: The battle of the reducing gases

Hydrogen vs. syngas: The battle of the reducing gases

Using our Climate system, scientists are able to unveil the most effective method to obtain sintering-resistant metallic cobalt nanoparticles at lower temperatures.

Original article by Ofentse A. Makgae, Tumelo N. Phaahlamohlaka, Benzhen Yao, Manfred E. Schuster, Thomas J. A. Slater, Peter P. Edwards, Neil J. Coville, Emanuela Liberti, and Angus I. Kirkland

The Fischer-Tropsch synthesis (FTS) is an established catalytic chemical process that occurs when carbon monoxide and hydrogen are converted into hydrocarbons. These hydrocarbons can be further developed into high-quality fuels, lubricants as well as raw materials for the production of plastics, rubbers and industrial chemicals. In FTS, supported cobalt catalysts are commonly used, which are active in their reduced metallic state. Many factors can affect the reduction process of cobalt oxide (Co₃3O₄) to metallic cobalt, including the reduction temperature, the composition of the reducing gas, the catalyst promoter, catalyst support and particle size. Despite this, little is known about the effect of using H₂ versus syngas (H₂ & CO) as the reducing agent on carbon-supported cobalt catalysts.

In recent research performed at the David Cockayne Centre for Electron Microscopy and the electron Physical Science Imaging Centre (ePSIC), a number of scientists from highly renowned universities and institutes, including University of Oxford, Johnson Matthey, Diamond Light Source and Cardiff University, investigate the atomic structure and valence state of cobalt nanocrystals on carbon supports under syngas versus hydrogen reduction. Specifically, using ex situ and in situ high-resolution aberration-corrected analytical electron microscopy with our Climate system, the researchers were able to explore the effect of H₂ versus syngas (H₂ & CO) on the reducibility of cobalt oxide nanoparticles supported on hollow carbon spheres. By uncovering highly effective methods to obtain sintering-resistant metallic Co nanoparticles at lower temperatures on hollow carbon sphere supports, this work provides valuable insights that can inform important industrial processes.

Synthesis and reduction of cobalt oxide

Dr. Ofenste Makgae and his fellow collaborators first synthesized the Co₃3O₄ nanoparticles before preparing the hollow carbon sphere supports (HCSs). The synthesized Co₃3O₄ nanoparticles were then loaded on the surface of the HCSs to prepare the precursor catalyst.

The researchers then initiated the reduction process of the Co₃3O₄ nanoparticles for both the ex situ and in situ analysis. For the ex situ analysis, the precursor was reduced via H₂ and syngas, respectively, at 350 °C at atmospheric pressure for 20 hours. For the in situ analysis, the catalysts were studied using the DENSsolutions Climate system in a probe-corrected JEOL ARM200F at ePSIC operated at 200 kV. Notably, the DENSsolutions Climate system is capable of real-time dynamic mixing of 3 gases over a temperature range from room temperature to 1000 °C. Via the Climate Gas Supply System, Dr. Makgae and his fellow collaborators were able to provide a 0.2mL/min flow of gas at a pressure of 500mbar for both the H₂ and syngas reduction. The temperature was ramped from room temperature to 150 °C under a N₂ flow to remove contaminants. Next, it was ramped to 350 °C at 10 °C/min under a reducing environment. Finally, the temperature was held at 350 °C for 2 hours for catalyst activation.

Ex situ post-reduction morphology analysis

The researchers then set out to analyze the overall morphology of the carbon support post reduction, to ensure that its integrity was not compromised during the reduction process. In Figure 1 below, (high-resolution) STEM-ADF images of the as-prepared Co₃3O₄ and ex situ syngas- and H₂-reduced HCS-supported nanoparticles are shown. The researchers were able to determine that the morphology of the HCSs remained intact after 20 hours of reduction at 350 °C.

Figure 1: STEM–ADF images of the Co nanoparticles (a) before and after the ex situ reduction in (b) syngas (H₂/CO = 2) and (c) H₂ at 350 °C. (d–f) are the corresponding high-resolution STEM–ADF images of the as-prepared Co₃3O₄, syngas-, and H₂-reduced nanoparticles.

EELS spectra and elemental maps

Aside from morphological changes, the oxidation state of cobalt also changes during the reduction process as a function of the reducing gas composition. Using STEM–EELS, the researchers were able to thoroughly investigate the Co-oxidation state changes. Figure 2 below compares the EELS spectra and elemental maps of single particles of the as-prepared Co₃3O₄, and the syngas-reduced and H₂-reduced nanoparticles. Via the EELS spectra analysis, the researchers determined that there was indeed a significant decrease in the oxidation state of Co.

Figure 2: EELS spectra of the as-prepared Co₃3O₄ (green), syngas- (orange), and H₂- (blue) ex situ reduced nanoparticles at 350 °C. EELS elemental maps of (b–d) as-prepared, (e–g) syngas-reduced, and (h–j) H₂-reduced Co₃3O₄ nanoparticles.

Importantly, the EELS spectra observations also show that the degree of reduction varies amongst the two methods (H₂ and syngas). To explore this further, the researchers collected additional spectra to compare the ex situ syngas-reduced and H₂-reduced nanoparticles at 350 °C, with the as-prepared Co₃3O₄ as a reference. From this further analysis, it is observed that the Co in the case of the syngas-reduced nanoparticles’ spectra is in a near-metallic state as compared to the H₂-reduced nanoparticles. These results are consistent with the elemental maps obtained, showing that a more intense Co signal (green) is observed in the elemental map from a syngas-reduced nanoparticle (Figure 2g), compared to a more diffuse Co signal in the elemental map of a H₂-reduced nanoparticle (Figure 2j). Ultimately, in the absence of air surface reoxidation, the results of the in situ STEM–EELS and ADF analysis show that syngas achieves a higher degree of Co reduction than H₂.

High-resolution STEM-ADF analysis

The next step for Dr. Makgae and his collaborators was to perform high-resolution STEM–ADF imaging in order to investigate the differences in the atomic structure associated with the observed differences in Co-oxidation states in the syngas- and H₂-reduced nanoparticles. They explored the reduction of the syngas- and H₂-reduced nanoparticles at two different temperatures, 350 °C and 600 °C.

1) At 350 °C

In Figure 3a–e below, the high-resolution STEM–ADF images of syngas-reduced nanoparticles (a–c) and H₂-reduced nanoparticles (d,e) are presented. The results were found to be consistent with the EELS data, showing that syngas reduction produces a majority of metallic Co nanoparticles, whereas H₂ produced particles with a majority of the Co in the 2+ oxidation state. 

Figure 3: High-resolution STEM–ADF images of ex situ (a–c) 350 °C syngas-reduced nanoparticles and (d,e) H₂-reduced nanoparticles.

2) At 600 °C

The temperature was then increased to 600 °C to investigate the effect of temperature on reducing HCS-supported Co₃3O₄ nanoparticles under H₂ versus syngas. It is observed that both the H₂- and syngas-reduced nanoparticles exhibit an atomic structure consistent with cobalt (Figure 4a–d). Indeed, the results are consistent with the EELS data from the 600 °C reduced nanoparticles, which shows the presence of metallic cobalt. Conclusively, in order to achieve a complete reduction of Co₃3O₄ under H₂, the HCS-supported nanoparticles must be reduced at high temperatures. Importantly, it is observed that the high temperature of 600 °C resulted in severe sintering of the nanoparticles reduced in H₂ compared to syngas. The sinter-resistance in syngas-reduced nanoparticles is attributed to the encapsulation of nanoparticles with a carbon shell (indicated by the orange arrow in Figure 4b). This encapsulation prevents the coalescence of the nanoparticles at high temperatures. Interestingly, in the case of the H₂-reduced nanoparticles, a carbon shell is not observed (Figure 4d).

Figure 4: High-resolution STEM–ADF images of 600 °C ex situ (a,b) syngas-reduced nanoparticles and (c,d) H₂-reduced Co nanoparticles.

Conclusively, the presence of CO in syngas is observed to play a critical role in the conversion of Co₃3O₄ to metallic Co at 350 °C. In contrast, the full reduction of Co₃3O₄ to active metallic Co in H₂ is not achieved at 350 °C. Increasing the activation temperature to 600 °C does drive the complete reduction, however, significant particle sintering was still observed. Therefore, the presence of CO in a syngas mixture is indeed crucial to achieving complete Co₃3O₄ reduction at 350 °C.

Conclusion

This paper comprehensively illuminates the most effective method to obtain sintering-resistant metallic cobalt nanoparticles at lower temperatures under carbon supports. By conducting a thorough ex situ and in situ electron microscopy analysis using the DENSsolutions Climate system, Dr. Makgae and his fellow collaborators were able to observe under nanometer resolution how the reduction process under H₂ versus syngas affects the physicochemical properties of the reduced nanoparticles. The findings show that syngas achieves a higher reduction at an industrially relevant Fischer-Tropsch reduction temperature of 350 °C compared to H₂ on carbon supports. Importantly, lower reduction temperatures are more efficient as operating costs are reduced, which is a significant consideration for organizations involved in industrial processes. The discovery of such findings could not be possible without the application of in situ electron microscopy techniques, for which our Climate system has proved to be remarkably valuable.

“The DENSsolutions Climate system allowed us to directly evaluate the reducibility of Fischer-Tropsch catalysts under industrially relevant temperatures. Such observations provide a unique insight into the evolution of catalysts under activation conditions.

Dr. Ofentse Makgae
Post-doctoral Research Fellow  |  Lund University

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Introducing the Stream Liquid Supply System: An integrated solution offering unmatched flexibility

Introducing the Stream Liquid Supply System: An integrated solution offering unmatched flexibility

An interview with DENSsolutions Mechanical Engineer Alejandro Rozene about our latest addition to the Stream product line: the Liquid Supply System (LSS).

DENSsolutions introduces its latest solution: the Stream Liquid Supply System (LSS): an integrated solution designed to offer you ease-of-use, flexibility and reproducibility in your in situ liquid experiments. In this article, we interview our Mechanical Engineer Alejandro Rozene to learn all about the LSS, from what inspired its development, its unique capabilities and the many applications that will benefit from its creation.

What led to the development of the Stream Liquid Supply System?

“Our Liquid Phase Electron Microscopy (LPEM) solutions have been used by researchers around the world in a plethora of research fields, such as protein studies, battery research and molecular self-assembly. With our Stream system, users can fully control the microfluidic environment inside the Nano-Cell, our environmental MEMS sample carrier, while biasing or heating their sample. Considering the wide range of capabilities the system offers and the complexity of LPEM, Stream is quite the advanced system. This is precisely what inspired the next step in the innovation process: the development of an integrated solution designed to offer greater flexibility and ease-of-use. The Liquid Supply System (LSS) is a single scientific instrument that allows microscopists to carry out imaging experiments in fewer steps while introducing new features. The LSS is also designed to be the basic unit of a modular system that can be configured for different research applications.” 

What are the main benefits of the LSS for users?

“The introduction of the LSS to the Stream product line brings forth numerous advantages for your in situ liquid experiments, including greater flexibility, reliability and reproducibility. These benefits are detailed below:

1) Ease of use: Thanks to the clever architecture of the LSS, particularly the moveable base, you can easily relocate, store and set it up in various locations. It is also possible to control the microfluidic environment of the Nano-Cell and to apply different stimuli using a single interface in Impulse, our in situ experiment control and automation software. All of the sensor data is collected centrally. The LSS therefore simplifies the LPEM workflow and allows you to shift the focus from the hardware to the imaging experiment. This will potentially open the door to more elaborate experimental workflows.

2) High resolution imaging and meaningful analytical analysis: It is widely known that LPEM suffers from limited resolution caused by the thickness of the liquid layer inside the sample chamber. Even a 500 nm liquid layer can limit imaging resolution. With the LSS, the capability of controllable and inert gas purging is introduced. This means that you can easily displace the liquid in the Nano-Cell and effortlessly cycle between dry and liquid environments. This can be done with air or with an inert gas for air-sensitive samples. Via purging, you can easily get rid of excess liquid in the sample, thereby allowing you to achieve high resolution imaging, image in electron diffraction mode and perform spectroscopy techniques: EDS and EELS.

3) Reliable and reproducible results: The components of the LSS, such as the inlet and outlet pressure-based pumps as well as the liquid flow meter, introduce an unprecedented level of control during your liquid phase microscopy experiments. The LSS offers the unique ability to actively measure the liquid flow, making it possible for you to compare results from different experiments. Moreover, this means that you can easily detect potential clogs in the system and act fast, allowing you to spend your TEM time efficiently and effectively. Ultimately, the combination of our LSS and unique Nano-Cell design, having an on-chip inlet and outlet, enables the liquid delivery to be both reliable and reproducible with a success rate of more than 95%.”

Which applications will benefit most from the LSS?

“The LSS is beneficial for any researcher who wants to use LPEM to observe hydrated samples, matter suspended in liquid or liquid itself in a dynamic environment. Some of the many fields that will benefit from the system include:

  1. Life Science: DNA imaging, biomineralization, cell imaging and protein studies
  2. Electrochemistry: studies of aqueous electrolytes and electrocatalysis
  3. Material Science: studies of nanoparticle formation, self-assembly and growth

These are just a few examples of the several fields that can benefit from the Stream system. Furthermore, the door is open to any researcher who may want to exploit the unique capabilities of the LSS for any liquid-based study outside of the TEM.”

What kind of challenges were tackled during development?

“The LSS is a state-of-the-art scientific instrument. As with any other mechatronic development, integrating the sensing, actuating and microfluidic components into a single, robust machine was in itself a challenge. Also, our market is especially demanding since the users of this instrument already work with some of the most advanced equipment out there, which undoubtedly sets the bar very high. However, it was a very enjoyable experience thanks to the incredible teamwork and collaboration of our MEMS Project Manager, Tijn van Omme, and our Software Developer, Emil Svensson, as well as our manufacturing partners.”

What is the compatibility of the LSS?

“The LSS is an integral part of our Stream product line. It is therefore fully compatible with the modular Stream sample holder, the Stream liquid biasing and liquid heating Nano-Cells, as well as with Impulse. With regards to the microscopes, compatibility is given by the holder type. We currently offer compatibility with JEOL and Thermo Fisher Scientific microscopes.”

Has the LSS already been installed?

“Yes, the Liquid Supply System has been installed at the University of Alberta Nanofabrication and Characterization Facility (nanoFAB) in Canada. The nanoFAB is a national, open-access training, service, and collaboration centre, focused on academic and industrial applications in micro- and nanoscale fabrication and characterization. The installation was carried out by our MEMS Project Manager, Tijn van Omme, with the support of our close distributor Colt Murray from Nanoscience Instruments. It is the first of several installations planned in the upcoming months.”

From left to right: XueHai Tan, Colt Murray, Tijn van Omme and Haoyang Yu

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Meet our new colleagues Dr. Vasilis Papadimitriou and Erkin Demir

Meet our new colleagues Dr. Vasilis Papadimitriou and Erkin Demir

We are excited to announce the expansion of our team with two new wonderful colleagues: our MEMS Development Manager, Vasilis, as well as our Lab Manager and Quality Control Engineer, Erkin.

DENSsolutions Eva Bladt

A prime focus of DENSsolutions is the innovation and further development of our in situ microscopy solutions, including those catered to the life science community. With this goal in mind, we wanted to expand our team with someone who could lead the development of our MEMS technology for liquid phase transmission electron microscopy. Over the past 15 years, Vasilis has acquired a unique and diverse pool of knowledge within numerous fields, including micro-/nanotechnology, Lab-on-a-Chip devices and life science applications such as point-of-care diagnostics and wearable optical biosensors. His role at DENSsolutions is focused on the development of new MEMS devices which will enable advanced in situ microscopy solutions for the scientific community.

Aside from innovation, DENSsolutions recognizes the need to deliver top-quality products that not only meet but exceed customer expectations. This is precisely the value that Erkin will bring forth in light of his five-year experience in quality control at the leading automotive and aerospace companies in Turkey. Erkin will be responsible for the internal and supplier-side quality control activities at DENSsolutions, as well as the implementation of valuable quality control tools to DENSsolutions processes. We asked Vasilis and Erkin to introduce themselves so you can learn more about their education, experience and role at DENSsolutions. 

Meet Dr. Vasilis Papadimitriou

“My name is Vasilis Papadimitriou and I am 33 years old. I was born and raised in a small town called Levadia in Greece, and in 2013 I moved to the Netherlands.

In 2006, I started my Bachelor in Electronics and Computer Engineering at the Technical University of Crete in Greece. After that, I pursued a Master’s degree in the same field where I focused on programming, electronics and telecommunications. For my MSc thesis, I investigated the use of DNA for complex mathematical algorithms (DNA computing). After my military service, I moved to the Netherlands in 2013 and dived into the world of micro-/nanotechnology as part of my MSc in Electrical Engineering at the University of Twente. During this MSc thesis, I created a novel carbon electrode for use in supercapacitors, which granted me deep insights into electrochemistry and fluid mechanics. 

After that, I decided to continue my studies with a PhD in University of Twente. The focus of my doctorate was on Lab-on-a-Chip devices. I’ve always enjoyed multidisciplinary science, and Lab-on-a-Chip devices integrate numerous fields such as microtechnology, physics, chemistry, biology and electrical engineering. The European project that my PhD was part of focused on the development of a point-of-care device for early diagnosis of cardiovascular diseases. My role was to separate and concentrate specific proteins from a droplet of blood. In 2019, I received my doctorate degree and since then, I have had two postdoctoral positions: one on artificial intelligence for Lab-on-a-Chip applications at the University of Twente, and another on wearable optical biosensors at the Technical University of Delft.

That brings us to today, where I am really happy to be part of the DENSsolutions team. Actually, I wasn’t previously familiar with in situ microscopy nor the company, which is really unfortunate since their (and now our!) products could have solved many of the challenges I faced during my PhD and postdoctoral work. My main role at DENSsolutions is to investigate new technologies and develop intelligent MEMS devices that will make electron microscopy easier, faster and reproducible. With more than 15 years of experience within academia, I am very much well-acquainted with the struggles of research. I hope through DENSsolutions I will make the lives of scientists easier, while at the same time expanding my engineering and scientific horizons.”

Meet Erkin Demir

“My name is Erkin Demir. I am a 28-year-old individual of Circassian origin who was born and raised in Turkey. As of February 2022, I moved to the Netherlands for my exciting new role at DENSsolutions.

I started my Bachelor in Gazi University in the field of metallurgical and materials engineering. For my Bachelor’s thesis, I did research on the current and potential uses of graphene. After my undergraduate degree, I started working as a Quality Engineer in Bozankaya, a top manufacturer for public transportation vehicles in Turkey. There, I had the opportunity of managing the supplier deployment and incoming quality control processes of the first domestic 100% electric buses and trams. This job granted me my first exposure into the intricacies and importance of quality control for the delivery of top-quality products. As a next step in my career, I became a Quality Engineer at Erkunt Tractor Ind. Inc., an renowned tractor manufacturer in Turkey. This position helped me obtain deeper insights into field of quality control as a whole, as I was involved in areas such as mass production, lean manufacturing, supplier development, 5S and similar processes.

Afterwards, I landed a job as a Lead Quality Engineer at the Tusaş Engine Industry Inc., the leading aviation engine manufacturer in Turkey. During my work there, I was fully responsible for the quality side of the NPI processes of some parts in aircraft engine programs. I worked on the implementation of advanced measurement methods to ensure the high precision and safety conditions associated with the aviation industry. I obtained a lean 6 Sigma yellow belt and AS 13001 DPRV certification after completing related courses and exams. Thanks to this SAE authorization, I became eligible to sell aero engine parts on an international level. In parallel with this position, I completed my Master’s degree in Metallurgical and Materials Engineering at Gazi University in 2020. For my Master’s thesis, I examined the performance of high temperature diffusion coatings on the corrosion resistance of nickel-based superalloys used in high pressure turbine blades.

Here I am now, a different country, a different industry, and some awesome teammates. I couldn’t be more excited and curious to embark on this new journey. My main role at DENSsolutions is to ensure the proper functioning of all our products so that our customers can conduct their research without disturbance. This includes performing meticulous inspections and tests at our lab on our world-class MEMS devices, TEM holders and fluid handling systems. Moreover, I will be working very closely with suppliers to ensure the highest possible quality level for our products. I am excited to be deploying all the best practices I have learned over the years into DENSsolutions, adding value step by step.”

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Vasilis

Erkin

Vasilis

Erkin

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Unraveling the dynamic behavior of zinc electrodes in aqueous electrolytes using our Stream system

Unraveling the dynamic behavior of zinc electrodes in aqueous electrolytes using our Stream system

Scientists are able to observe for the first time using in situ TEM the morphology and phase evolution of zinc anodes during zinc dissolution and deposition in aqueous electrolytes.

Original article by Yongfeng Huang, Qingqing Gu, Zhanglong Guo, Wenbao Liu, Ziwen Chang, Yuefeng Liu, Feiyu Kang, Liubing Dong, Chengjun Xu

Marc Willinger TOC 1200x628

Metallic zinc is a widely used electrode material for aqueous rechargeable zinc-ion batteries (ZIBs) due to its high theoretical capacity, low redox potential, natural abundance and low cost. Despite these valuable benefits, zinc electrodes suffer from short cycling stability due to many factors such as the growth of zinc dendrites as well as corrosion. Little is known about the underlying reasons for the failure of zinc anodes on a deeper level. Indeed, the use of in situ transmission electron microscopy can serve as a means to bridge this gap in knowledge, unraveling the morphological evolution of zinc anodes during zinc dissolution and deposition in aqueous electrolytes. 

In recent research performed at the DICP-DENS Microscopy Centre by Dr. Yuefeng Liu from the Dalian Institute of Chemical Physics, Yongfeng Huang from Tsinghua University, and many more collaborators, they were able to obtain a deep understanding of the stripping/plating behaviors of zinc in various aqueous electrolytes using the DENSsolutions Stream system. Specifically, the researchers investigated the effects of adding Mn²⁺ and CF₃SO₃⁻ in zinc-salt aqueous electrolytes on the zinc plating/stripping behavior. This work not only sheds light on the mechanism of zinc anodes during zinc dissolution/deposition processes in aqueous electrolytes, but also provides effective strategies to achieve long-term stable rechargeable zinc-ion batteries (ZIBs). 

Three aqueous electrolytes

As the high reversibility of zinc anodes is a prerequisite for large- scale applications of ZIBs and ZHSs, many efforts have been dedicated to achieve long-term stable zinc anodes. One effective way to stabilize and acquire dendrite-free zinc anodes is by introducing additives in aqueous electrolytes. In previous studies, it was found that the addition of Mn²⁺ in the form of MnSO₄ to a ZnSO₄ aqueous electrolyte can actually suppress the dissolution of the MnO₂ cathode. Similarly, in comparison to a ZnSO₄ electrolyte, a Zn(CF₃SO₃)₂ electrolyte is far more effective in achieving better electrochemical performance of many ZIB systems.

For these reasons, aside from a pure ZnSO₄ electrolyte, ZnSO₄/MnSO₄ and Zn(CF₃SO₃)₂ are commonly used aqueous electrolytes for ZIBs. Despite this, zinc plating/stripping behaviors in ZnSO₄/MnSO₄ and Zn(CF₃SO₃)₂ and their effects on electrochemical stability of metallic zinc anodes are unknown. In this study, the researchers combine operando TEM and electrochemical analysis to unravel the zinc stripping/plating behaviors in the three aqueous electrolytes detailed above (ZnSO₄, ZnSO₄/MnSO₄ and Zn(CF₃SO₃)₂). In the following sections, in situ TEM images and videos of the zinc stripping/plating process in the three different electrolytes are shown.

1) Zinc plating/stripping process in a ZnSO₄ electrolyte

The researchers first constructed a micro zinc-ion battery inside the Stream holder, allowing them to monitor the zinc plating/stripping processes using the system’s on-chip flow channel. After assembling the Stream Nano-Cell and leak-testing it, the researchers were then able to flow the electrolytes into the liquid cell, using the pressure-based liquid pump to fully control the rate of the flow. 

Next, the researchers set out to observe the zinc stripping/plating behavior in a pure ZnSO₄ aqueous solution. In Figure 1 below, the in situ TEM images detailing the zinc plating and stripping process at different times in 2 M ZnSO₄ are shown. During the zinc plating process exhibited in Figure 1a–d, the thickness of zinc deposited on the platinum substrate increases. Simultaneously, dendrite-like structures form and develop gradually. This confirms the dendrite issue of metallic zinc electrodes in the 2 M ZnSO₄ electrolyte, which leads to a short-circuit occurrence. After this, the zinc stripping process occurs, which is demonstrated in Figure 1d–f. During this process, it is observed that the deposited zinc is unable to fully strip away from the platinum substrate and dissolve into the electrolyte under the same charge and discharge time conditions. As a result, dead zinc is generated (see Figure 1f).

Figure 2: Marc Willinger

Figure 1: In-situ TEM images of zinc plating/stripping on the surface of Pt working electrode in 2 M ZnSO₄ electrolyte at different times: (a) 0 s, (b) 3 s, (c) 10 s, (d) 28 s, (e) 80 s and (f) 261 s.

Electrolytes of high concentrations are generally not conducive for monitoring zinc stripping/plating behaviors using in situ TEM, as they can block out the liquid inlet hole of the holder. Due to this, along with the valuable insights that further investigating the effect of concentration on dendrite growth can provide, the ZnSO₄ electrolyte was diluted from 2 M to 20 mM. The researchers then observed the zinc stripping/plating process in the 20 mM ZnSO₄ aqueous electrolyte. The in situ TEM images and corresponding movie detailing this process can be seen below in Figure 2 and Video 1, respectively. 

The zinc stripping/plating process was controlled using the cyclic voltammetry (CV) technique at 20 mV/s. Figure 2g shows the corresponding CV curve, where the red dots marked as a–f correspond to the states in Figure 2a–f. At 71s (see Figure 2b), the researchers observed that the visible zinc particles in the electrolyte, as well as the dense dispositioned zinc and the zinc dendrites (marked in green) on the surface of the Pt substrate occur at the same. Between 76s–95s (Figure 2c-d), they noticed that more zinc was plating on the platinum surface, with the potential ranging from − 1.41 V to − 1.1 V. Next, the process of zinc dissolution occurs, where the zinc frontier line is observed to shrink back to area II at 114s (Figure 2e) and to the edge of the Pt substrate at 144s (Figure 2f). It is observed that the dendrite is still not completely removed when the potential returns to 0 V. Conclusively, although reducing the concentration can slow down dendrite formation, it does not fully suppress it.

Figure 2: In-situ TEM images of zinc plating/stripping on the surface of Pt working electrode in 20 mM ZnSO₄ electrolyte at different times: (a) 0 s (b) 71 s, (c) 76 s, (d) 95 s, (e) 114 s and (f) 144 s. (g) CV curve of zinc stripping/plating process on the surface of Pt working electrode in 20 mM ZnSO4 electrolyte at a scan rate of 20 mV/s. (h) XRD pattern after zinc plating/stripping at Pt. (i) XPS result after zinc plating/stripping at Pt.

Video 1: Video of zinc plating/striping at the interface of Pt working electrode in 20 mM ZnSO₄ electrolyte.

2) Zinc plating/stripping process in a ZnSO₄/MnSO₄ electrolyte mixture

The next step for the researchers was to observe the zinc stripping/plating process in a ZnSO₄/MnSO₄ electrolyte mixture, as MnSO₄ additives in ZnSO₄ electrolytes can actually optimize the electro-chemical stability of metallic zinc electrodes. They first added 5 mM MnSO₄ to the 20 mM ZnSO₄ aqueous electrolyte. The in situ TEM images and corresponding movie detailing the resulting zinc plating/stripping process can be seen below in Figure 3 and Video 2, respectively. 

Figure 3a–d depicts the zinc plating process, in which Mn spherical particles appear and gradually increase in size. At 124s (see Figure 3e), the zinc stripping process starts to occur, and these spherical particles in the electrolyte begin to disintegrate and finally disappear at 259s (see Figure 3i). Aside from the spherical particles in the electrolyte, a visible amount of deposited zinc (marked in green in Figure 3e) appears on the Pt working electrode. Notably, the sphere species, both in the electrolyte and also on the surface of the Pt substrate, disintegrate. This results in the further precipitation of zinc and leads to the increased thickness of zinc. Interestingly, zinc dendrites were not observed to form in the ZnSO₄/MnSO₄ electrolyte mixture, unlike in the pure ZnSO₄ electrolyte. This directly suggests that the Mn²⁺ additive is indeed beneficial for suppressing the formation of zinc dendrites.

Figure 3: Zinc stripping/plating behaviors in 20 mM ZnSO₄ + 5 mM MnSO₄ electrolyte at different times: (a) 0 s (initial state), (b) 60 s (c) 69 s, (d) 119 s, (e) 124 s, (f) 177 s, (g) 199 s, (h) 238 s and (i) 259 s. (j) Cyclic voltammogram curve of Zn plating and striping at the interface of Pt working electrode at a scan rate of 20 mV/s, the red dots are assigned to Figure a-i, (k) XRD pattern after zinc plating/stripping at Pt (CaCO₃ is from the XRD bonding adhesives), and (l) E-pH diagram of Mn.

Video 2: Video of zinc plating/striping at the interface of Pt working electrode in the 20 mM ZnSO₄ + 5 mM MnSO₄ electrolyte.

3) Zinc plating/stripping process in a Zn(CF₃SO₃)₂ electrolyte

Finally, the researchers set out to explore the zinc plating/stripping process in a 20 mM Zn(CF₃SO₃)₂ electrolyte. The in situ TEM images and corresponding movie detailing the resulting zinc plating/stripping process in this electrolyte is shown in Figure 4 and Video 3, respectively. The zinc plating process is depicted in Figure 4a–d, where particle-like zinc uniformly deposits on the surface of the Pt substrate, and the thickness of the deposited zinc layer increases. Here, no zinc dendrites form during the plating process. At 175s (see Figure 4e), the zinc stripping process starts, and the deposited zinc particles on the Pt substrate gradually dissolve into electrolyte. Finally, at 240s (see Figure 4f), all zinc particles disappear, demonstrating the high reversibility of zinc deposition/dissolution in the Zn(CF₃SO₃)₂ electrolyte. Importantly, the deposition of zinc on the Pt substrate in the Zn(CF₃SO₃)₂ electrolyte is more uniform and homogeneous than that in the ZnSO₄ electrolyte and ZnSO₄/MnSO₄ electrolyte mixture.

Figure 4: Zinc stripping/plating behaviors in 20 mM Zn(CF₃SO₃)₂ electrolyte at different times: (a) initial, 1.0 V (b) 124 s, -1.48 V, (c) 130 s, -1.40 V, (d) 138 s, -1.24 V, (e) 175 s, -0.40 V, (f) 240 s, 0.80 V, (g) Cyclic voltammogram curve at the scan rate of 20mV/s about Zn plating and striping at the interface of Pt working electrode in 20 mM Zn(CF₃SO₃)₂ electrolyte, the red dots are assigned to Figure a-f (h) XRD pattern after zinc plating/stripping at Pt (CaCO3 is from the XRD bonding adhesives). (i) SEM image after Zn plating on Pt.

Video 3: Video of zinc plating/striping at the interface of Pt working electrode in the 20 mM Zn(CF₃SO₃)₂ electrolyte.

Conclusion

This paper provides a novel understanding of the failure process of metallic zinc electrodes in a ZnSO₄ electrolyte, as well as the effects and acting mechanism of Mn²⁺ in the ZnSO₄/MnSO₄ electrolyte mixture and CF₃SO₃⁻ in the Zn(CF₃SO₃)₂ electrolyte on the zinc plating/stripping behavior. These deep-level insights serve to close the gap in our understanding of how we can create long-term stable ZIBs with metallic zinc anodes and optimal aqueous electrolytes, beneficial for several critical applications, including large-scale energy storage and portable electronic applications. The discovery of such findings could not be possible without the application of in situ characterization techniques, for which our Stream system has proved to be remarkably effective.

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Scientists develop a novel approach to generate extreme thermal gradients using our Wildfire Nano-Chip

Via a simple modification to our Wildfire Nano-Chip, scientists show that extreme thermal gradients across a TEM specimen can be generated.

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Scientists develop a novel approach to generate extreme thermal gradients using our Wildfire Nano-Chip

Scientists develop a novel approach to generate extreme thermal gradients using our Wildfire Nano-Chip

Via a simple modification to our Wildfire Nano-Chip, scientists show that extreme thermal gradients across a TEM specimen can be generated.

Original article by Sriram Vijayan, Rongxuan Wang, Zhenyu Kong and Joerg R. Jinschek

Marc Willinger TOC 1200x628

In traditional manufacturing processes, it is typically observed that the material experiences steady-state conditions. This results in the formation of stable equilibrium phases in the material. However, for those phases in materials that develop under ‘far-from equilibrium’ conditions, the same does not apply. In fact, for certain processing techniques that involve rapid thermal cycling and/or extreme thermal gradients, changes in the local phase equilibria, and therefore the local microstructure, often occur. Currently, observing these dynamic processes in materials under such conditions remains a great challenge. This is particularly because MEMS-based in situ TEM heating devices that can generate thermal gradients, combined with the capability to thermally cycle a specimen between different temperatures, are not currently available.

In recent research performed at The Ohio State University by Dr. Sriram Vijayan and Dr. Joerg Jinschek (now at Technical University of Denmark), as well as Rongxuan Wang and Dr. Zhenyu Kong from Virginia Tech, it is shown that controlled thermal gradients across a TEM specimen can be generated via a simple modification to our Wildfire Nano-Chip. Such a device can dramatically improve our understanding of material performance under extreme thermal conditions. Until now, thermally activated processes that affect microstructural stability of a material exposed to such thermal transients could only be investigated postmortem. Therefore, the need for new approaches to study thermally activated phenomena in materials in real time under such conditions is required. Importantly, this work is a major step forward in paving the way for scientists to be able to perform site-selective studies on materials under transient thermal conditions.

The study

As a first step, Dr. Vijayan and his fellow collaborators made modifications to a standard DENSsolutions Wildfire Nano-Chip. They then measured the local temperature distribution across the modified Nano-Chip and sample, and thereby the thermal gradient. The magnitude of the thermal gradient generated by this modified MEMS-based microheater was determined by measuring the temperature distribution using a combination of ex situ and in situ temperature measurement techniques. Regarding the ex situ temperature calibration, Dr. Vijayan and Dr. Jinschek teamed up with their MURI partners at Virginia Tech. As for the in situ temperature calibration, this was done at CEMAS, the state-of-the-art electron microscopy facility at The Ohio State University, using the previously established ‘Ag nanocube sublimation method’. 

The Nano-Chip modification

Using a Helios Nanolab 600 DualBeam focused ion beam (FIB)/scanning electron microscope (SEM), the researchers were able to modify a standard Nano-Chip. The Ga+ ion-based FIB was operated at an accelerating voltage of 30 kV and 6.4 nA beam current to mill a rectangular window next to the spiral metallic heater. This milled window can be seen in Figure 1b below. Importantly, after the FIB modification, the modified Nano-Chip exhibited no signs of deterioration in performance. 

Figure 2: Marc Willinger

Figure 1: SEM images of the (a) unmodified Nano-Chip and (b) modified Nano-Chip.

Lamella preparation and transfer

Next, the researchers worked on preparing and transferring the FIB lamella from a (001) oriented single crystal silicon wafer surface onto the Nano-Chip. This workflow is detailed in Figure 2a–f below. The FIB-cut Si lamella was placed across the larger window (Figure 2e), with one end of the lamella on the heater and the other end on the SiN membrane acting as the heat sink. The Si lamella was welded to the MEMS heater using a Pt-based Gas Injection System (GIS) needle with the aid of the Ga ion beam. The Pt was welded at the top left edge and top right edge of the lamella as seen from the SE Image in Figure 2f.

Figure 2: Marc Willinger

Figure 2: Secondary electron (SE) and ion (SI) images of the FIB preparation and transfer of the lamella over the modified window in the FIB.

Ex situ temperature calibration

At Dr. Kong’s lab (Virginia Tech), the researchers then performed infrared thermal imaging (IRTI) experiments on the MEMS devices under ambient air conditions. IRTI is a particularly useful ex situ approach to measure the spatial distribution of temperature across the MEMS-device with a reasonable degree of accuracy. Using IRTI, the temperature distribution was measured across both the unmodified and modified Nano-Chip. 

1) Temperature distribution across the unmodified Nano-Chip

First, the researchers measured the temperature distribution across the unmodified Nano-Chip to obtain reference temperature measurements. This distribution indicated that the metallic spiral heating element surrounding the viewing area of the microheater exhibited the highest temperature. Moreover, based on the temperature profile of the MEMS microheater, the spiral metallic heating element is the “hottest” region, while the surrounding SiN membrane is the “coldest” region on the MEMS device. These thermal conditions result in a large thermal gradient between the spiral metallic heater (= the “heat source”) and the SiN membrane (= the “heat sink”). 

2) Temperature distribution across the modified Nano-Chip

In order to generate a thermal gradient across a specimen, a FIB-cut lamella must be placed such that one end of the specimen is on or adjacent to the heater and the other end is on the SiN membrane, away from the heater. 

The researchers then performed IRTI again, but on the modified Nano-Chip with a FIB-cut lamella of Si placed across the modified window. As shown in Figure 3a below, the “hot end” of the Si lamella was adjacent to the outer spiral of the metallic heater, represented by the region enclosed in the black dotted square. On the other hand, the “cold end” was across the window in the SiN membrane, represented by the region enclosed in the yellow dotted square. Next, the thermal gradients across the FIB-cut TEM specimen were measured via an established technique that allows temperature measurement inside the TEM with high spatial resolution. 

Figure 2: Marc Willinger

Figure 3: Overlay of the SEM image of the modified device with Si lamella on the thermal map of the device at 1300°C (unit of heatmap scale is in C), (b) the horizontal temperature line profile along the “hot end” (enclosed in dotted black square) and “cold end” (enclosed in dotted yellow square) of the Si lamella.

In situ temperature calibration

In order to validate the ex situ results and accurately measure the temperature across the FIB-cut specimen, the researchers measured the temperature via the established Ag nanocube (NC) sublimation method. The lamella was again placed such that the “hot end” was over the central spiral metallic heater and the “cold end” across the modified window. Next, monodispersed Ag NCs were dispersed onto the FIB lamella. The modified Nano-Chip was then heated to a set point temperature of 1,000°C and held until the Ag NCs completely sublimate. In Figure 4a below, the Ag NCs that dispersed across the FIB lamella are highlighted with colored boxes and labeled as regions 1–7. After sufficient sublimation events on the lamella were observed, the sublimation experiment was halted. Notably, the Ag NCs in region 6 and 7 did not completely sublimate, as the sublimation kinetics slowed down at lower temperatures. 

“When exposing the FIB-cut TEM lamella to a combination of extreme thermal gradient heating and thermal cycling, the DENSsolutions Nano-Chip was observed to be extremely stable. The impulse software was very useful for these experiments as it allowed us to design complex temperature profiles during the heating experiments.” – Dr. Sriram Vijayan, Post-Doctoral Researcher, Center for Electron Microscopy & Analysis (CEMAS), The Ohio State University

The researchers then estimated the mean temperature of the Ag NCs on the FIB lamella found within regions 1–5. Subsequently, the mean temperatures obtained from regions 1 to 5 were plotted against the relative distance from the heater. In figure 4b below, a linear fit of the temperature data with 95% prediction intervals is presented. The thermal gradient of ΔT/Δx = 6.3 x 10⁶ °C/m was calculated at the temperature set point of 1,000°C. 

The in situ results confirm that the researchers’ proposed modification of our Wildfire Nano-Chip has indeed generated a large thermal gradient across the FIB-cut TEM specimen. In fact, this resulting thermal gradient was found to be in the range of gradients observed in several engineering and manufacturing applications. Ultimately, this innovative approach now opens up the scope of research to address a wide range of material science problems observed under transient thermal conditions.

Figure 2: Marc Willinger

Figure 4: (a) SEM image of different regions (1–7) across the Si lamella where the temperature of the lamella was measured. (b) The linear fit of the temperature from the “hot end” to the “cold end” superimposed over the plot of the measured sublimation temp from region 1 to 5 versus distance from the “hot end”.
.

Conclusion

This paper presents a very simple methodology to study non-equilibrium processes in materials under extreme thermal gradients and rapid thermal cycling conditions. Specifically, this modified Nano-Chip can enable dynamic studies of the microstructural evolution in materials used in several critical applications, including nuclear reactor components, microelectronic packages and additively manufactured builds. 

In the case of metal-based additive manufacturing (AM), extreme spatial and temporal thermal transients significantly impact the material microstructure within the melt pool and regions below the melt pool (‘previously melted’ layers of an AM build). Using this novel in situ TEM heating approach, we can now begin to observe and understand physical processes that contribute to the microstructural evolution in ‘previously melted’ layers during AM, thereby closing gaps in our understanding of processing-structure-property relationships in metal-based AM.

Ultimately, this powerful device can accurately simulate these complex thermal conditions inside the TEM and capture the microstructural evolution of materials during such extreme processing conditions. We are truly proud of the role that our Wildfire system has played in making this research possible and strive to continue enabling groundbreaking research now and in the future.

Hanglong Wu portrait

“Our modified DENSsolutions Wildfire Nano-Chip is well-suited for in-situ TEM heating experiments that require ‘far-from-equilibrium’ thermal conditions. This enables the observation of dynamic processes in a wide range of material systems at the nanoscale, which will further our fundamental understanding on microstructural stability of materials during processing and under ‘in-service’ conditions.” 

Dr. Joerg Jinschek
Professor |  Technical University of Denmark

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New measuring technique proves exceptional temperature accuracy of our Wildfire Nanochip

In collaboration with Utrecht University, we develop a novel technique to measure temperature at the nanoscale, showing the remarkable temperature accuracy and homogeneity of our Wildfire Nanochip.

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DENSsolutions has installed yet another Stream system in Germany at Forschungszentrum Jülich

DENSsolutions has installed yet another Stream system in Germany at Forschungszentrum Jülich

DENSsolutions Installing South Korea's second Stream system at Seoul National University

From left to right: Andreas Körner and Dr. Andreas Hutzler

We are proud to announce that DENSsolutions has installed yet another Stream system in Germany at the esteemed Forschungszentrum Jülich, one of the largest interdisciplinary research centres in Europe. In this article, we interview Dr. Andreas Hutzler, the new head of the TEM lab in the Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (HI ERN) at Forschungszentrum Jülich, to learn more about their advanced microscopy facility, its research direction, as well as how our Stream system is advancing their research.

Can you tell me more about the microscopy facility at HI ERN?

“The Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (HI ERN) is part of the Forschungszentrum Jülich. It specializes in providing crucial research on technologies needed to utilize renewable energies in the decades to come. Our research is centered around fuel cells, electrolyzers and hydrogen storage. The institute was founded in 2013 and has been growing ever since. In 2021, its new research building was inaugurated, hosting the space for a new transmission electron microscope, the Talos F200i from Thermo Fisher Scientific. This tool provides in-house structural analysis on the nanoscale for catalysts, support systems and membranes.”

What type of applications are the users at HI ERN using the Stream system for?

“Our goal is to study electrochemical processes taking place on electrode and catalyst surfaces within electrolyzers and fuel cells down to the atomic scale. We aim to understand which reactions take place, and which conditions enhance the performance of the cells or disintegrate the structures involved.

In order to understand this, we consider beam-induced effects onto the solution chemistry we investigate. For this, we utilize a comprehensive radiolysis model for unraveling the influence of electron irradiation onto the sample and compare the results to non-biased experimental observations. Once this is understood, we continue with analyzing dynamic processes at the nanoscale to gain insights into reaction pathways and degradation mechanisms in P2X and X2P applications.”

What particular features of the DENSsolutions Stream solution attracted you to the system?

“In order to understand observable processes and their correlated chemistry, it is necessary to accurately tune experimental conditions while operating the system. The ability of the Stream system to flexibly adjust pressure, flux, temperature and potential allows to run a manifold of experiments in a wide parameter space. This is needed in order to verify the stability of our reaction kinetic models and for testing electrolysis at borderline conditions. Before, the structures could only be studied after the reaction has taken place. But the ability to directly observe dynamic processes on-site in real time gives valuable insights in the chemistry at hand.”

Can you tell me about the grant that was won to acquire the system?

“One of our key research interests is the development of new methods for characterizing fundamental and applied processes in electrocatalysis relevant to electrochemical energy conversion. After establishing identical-location TEM (IL-TEM) for energy applications and with the start of my team, a new transmission electron microscope as well as equipment needed for in situ liquid-phase TEM was funded by and installed at HI ERN. This particular toolbox will be a great asset for the nanoanalysis of electrochemical processes in my team which will enable unique insights in energy research.”

In your experience so far, how have you found the Stream system?

“The modular architecture of the Stream system enables a very versatile applicability without risking leakage or cross-contaminations. The performance of LP-TEM is considerably enhanced due to the controllability of liquid flow, the ever-present window bulging via the utilization of a novel chip design as well as a differential pumping system as a standard. Moreover, DENSsolutions came forward with providing non-standard solutions in order to provide compatibility with other setups at our institute.”

DENSsolutions Prof. Jungwon Park
Dr. Andreas Hutzler
Head of the Transmission Electron Microscopy lab| HI ERN, Forschungszentrum Jülich

Dr. Andreas Hutzler is the new head of the Transmission Electron Microscopy lab at HI ERN, PI of multiple projects at HI ERN and university and is currently setting up a team for nanoanalysis of electrochemical processes. His research interests mainly focus on methodological aspects of LP-TEM and its application in electrochemical energy conversion.

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Announcing DENSsolutions’ new CEO: Dr. Hugo Pérez-Garza

Announcing DENSsolutions’ new CEO: Dr. Hugo Pérez-Garza

An interview with Dr. Hugo Pérez-Garza, the newly appointed CEO of DENSsolutions.

We are excited to announce the appointment of DENSsolutions’ new CEO: Dr. Hugo Pérez-Garza, a longstanding pillar within this company. Dr. Hugo Pérez-Garza is a highly experienced and well-regarded leader with a strong feel for both science and business. During the last 3 years, Hugo has passionately and successfully led the technological roadmap and strategic positioning of DENSsolutions as Chief Technology Officer. With his unique skillset, extensive experience and diverse knowledge, Hugo certainly has the blueprint to propel the success of DENSsolutions to unprecedented heights.

In this article, we interview Hugo to learn everything from how this appointment came to be, the changes he would like to implement as the new CEO, to the exciting vision he has for DENSsolutions.

Can you tell us a little bit about how your appointment of CEO came to be?

“After many years of hard work, full of achievements thanks to his never-ending commitment to deliver results and his capability for entrepreneurial vision, our former CEO, Mr. Ben Bormans, reached his age of retirement. I´ve been very lucky in my career to have learned from someone like Ben, and I´m very thankful for the opportunity he has given me to join this amazing company. Throughout all these years of working together, Ben was the mentor who coached me and challenged me to become a better version of myself. Particularly during my former years as the CTO, Ben gave me all the trust and confidence to completely steer the direction of this company from a technological standpoint, while advising me on how to steer also from a business perspective. So after his decision to retire, I received the trust from him and the shareholders to step in as the new CEO, and thus to provide business growth, new energy and opportunities to move in new directions.” 

How do you feel your knowledge and experience will further the success of the DENSsolutions as the new CEO?

“I feel that I’m at a point in my career where I have the right combination of experience, ambition and energy in order to embark upon a nice professional challenge like this. But in particular, I believe that I have a strong knowledge base about the business and its technology, its customers and the external factors that are likely to impact our company. This should allow us to achieve a better match between our technical vision and our business ambition, and it will help me to identify faster the things that might need to change, so that decisions can be executed in a structured and properly planned manner. At the end of the day, I intend to bring innovation to our business model, our strategy and our people management style. By doing this, I want to highlight the importance of putting ‘dynamics ahead of mechanics’.” 

What are some changes you would like to implement as DENSsolutions’ newly-appointed CEO?

“First of all I want to implement new internal procedures to increase and strengthen the alignment among different departments. During this process, I want to ensure that I match our talent to value, which goes beyond employee engagement, and combine speed with stability. Before the end of this year, I want to get the whole team aligned on our upcoming roadmap, but also on the vision that I have for the medium and long term. This will help us become more efficient in how we operate. Overall I want to promote a forward-looking agenda and empower our employees to exploit their talents to the fullest.”

What vision do you have for DENSsolutions in the near future?

“One of the things that I´ve always highlighted about DENSsolutions, is the enormous talent of our people and the strength of our team. When you have these assets, and you combine them with a strong vision, great things can happen. And that’s precisely the foundation that I’m laying on for our near, medium and long-term future. For the near future, I want to ensure that we can finalize and launch some important and new developments, which will strengthen our value proposition and our presence in the market. But since technological innovation (and thus the RnD department) is not the only crucial aspect of our business, I also intend to set in motion new ideas for marketing, sales and operations. The roadmap is already in motion, and we are fully committed to delivering increasing value to our customers.”

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DENSsolutions Climate system takes home the microscopy today 2021 innovation award

DENSsolutions’ Climate system takes home the Microscopy Today 2021 Innovation Award

DENSsolutions becomes a consecutive two-time winner of the Microscopy Today Innovation Awards. This year, our Climate system is recognized as one of the 10 most game-changing microscopy innovations of 2021.

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Climate helps uncover phase coexistence and structural dynamics of redox metal catalysts

Climate helps uncover phase coexistence and structural dynamics of redox metal catalysts

Using our Climate system, scientists are able to interrelate the atomic-scale structural dynamics of redox metal catalysts to their activity.

Original article by Xing Huang, Travis Jones, Alexey Fedorov, Ramzi Farra, Christophe Copéret, Robert Schlögl, and Marc-Georg Willinger

Marc Willinger TOC 1200x628

Metal catalysts have been extensively studied due to their critical role in industrial redox reactions. However, many gaps in research still remain, hampering the optimization of their design. Specifically, the behavior of metal catalysts under operating conditions and the relationship between structural dynamics and catalytic activity are still not fully understood. Indeed, an atomistic comprehension of the structure–activity relationship of working catalysts is essential for the optimization of their design. 

In their recently published paper, Dr. Marc-Georg Willinger from ETH Zurich, Dr. Xing Huang from Fuzhou University and fellow collaborators from the Fritz-Haber Institute of Max-Planck Society and the Max Planck Institute for Chemical Energy Conversion explore the phase coexistence and structural dynamics of redox metal catalysts. Using our Climate system, the researchers are able to achieve controlled gas-flow and imaging, obtaining atomic-level insights into the correlation between the structural and chemical dynamics and catalytic function. In light of today’s environmental challenges, the development of improved catalysts for more resource-efficient processes is becoming increasingly critical. Importantly, developing improved catalysts requires their direct observation during operating conditions. In this work, the authors have obtained atomic-scale insights into catalyst dynamics in various relevant redox reactions.

Redox reactions

Copper is a popular transition metal used as an active component in redox catalysts for many reactions, including CO₂ reduction and water gas shift reaction (WGSR). However, an atomistic description of the state of copper under redox conditions in these catalysts remains unrealized. In this publication, Dr. Willinger and his fellow collaborators present a detailed, high-resolution study of copper during the hydrogen oxidation reaction (HOR), revealing fundamentals of catalyst dynamics under reactive conditions. Beyond the elementary hydrogen oxidation reaction, the researchers extend the observed dynamic behavior to more relevant redox reactions and other metal catalysts. Specifically, they explore the redox dynamics of copper and palladium in the active state during methanol oxidation and methane oxidation reactions, respectively.

Hydrogen oxidation reaction on copper

Studying HOR offers the opportunity to obtain detailed atomistic insights into the reaction between the catalyst and the gas phase. HOR was chosen because it is the most elementary redox reaction and yields only water as a product, thereby reducing the complexity related to potential electron-beam-induced processes. In this study, the researchers systematically assess the effects of temperature and gas-phase conditions. Moreover, they explore how the chemical potential of the gas phase defines the phase, size, and shape of catalyst particles, driving the system into a nonequilibrium dynamic state during catalysis. Due to the simultaneous detection of catalytic conversion, they are able to relate directly the observed dynamics and surface structures to catalytic activity. 

1) Redox dynamics and structural analysis of Cu

Copper nanoparticles of 50–200 nm were first loaded in the Climate Nano-Reactor. In situ TEM images of the copper nanoparticles were then recorded. It was found that the particles exhibit rich structural dynamics, which are associated with reconstruction and random motion, as well as particle sintering and red-ox induced splitting. The figure (A–L) and movie below depict these structural dynamics. Shown in M) is the integrated SAED pattern and corresponding radial intensity profile. The in situ SAED revealed dynamically appearing and disappearing diffraction spots, and confirmed the presence of metallic copper and Cu₂O as the sole oxide phase. The constant competition between oxide growth and reduction are reflected in the in situ SAED and the observed structural dynamics. Indeed, the structural dynamics are a consequence of chemical dynamics, characterized by phase coexistence and continuous interconversion between Cu⁰ and Cu₂O. The high-resolution imaging in Figure 1N) confirms this, showing a metallic head coherently interfacing with an oxide tail.

Figure 2: Marc Willinger

Figure 1: The redox dynamics and structural analysis of Cu. A–L) show the in situ TEM observations of catalyst reshaping (A–D), sintering (E–H), and splitting (I–L). In M) the integrated SAED pattern and corresponding radial intensity profile are shown. N) shows the HRTEM image of a nanoparticle containing a metallic head coherently interfacing with an oxide tail.

Movie 1: The redox dynamics of copper showing catalyst reshaping, sintering and splitting.

2) Effects of temperature and gas-phase composition

The authors then sought out to explore the effect of temperature on the observed redox dynamics. First, the temperature was decreased from 500 to 300°C, while maintaining a H₂/O₂ ratio of 10/1. During the temperature decrease, the researchers observed the growth of oxide dendrites, which reflects the increasing oxidation potential. Simultaneously, due to the slower kinetics of the redox reaction at lower temperatures, a reduction of the structural dynamics was observed. During heating from 300 to 750 °C, the system passes through a regime of increased dynamics (550 °C) that are characterized by translational motion and restructuring due to oxide growth and reduction, until it finally reaches a state that is less dynamic and dominated by metallic copper at 750°C. This is shown in the figure below (A–D). The reconstructed HRTEM images taken at 300 and 750°C are shown in 2E) and 2F), respectively. Next, integral SAED (Figure 2G,H) was performed to investigate phase analysis, revealing the relation between phase composition and temperature. It has been previously demonstrated that the trend in the oxide content reflects the decreasing chemical potential of oxygen with increasing temperature. However, the authors observe a notable exception of this general trend at around 550 °C, which is mostly due to the effect of water that is produced at substantial rate and contributes to the redox dynamics.

Figure 2: Marc Willinger

Figure 2: Chemical potential versus structural dynamics of Cu. A–D) In situ TEM observation of dynamics at 300–750 °C and a H₂/O₂ ratio of 10/1. E,F) show the reconstructed HRTEM images taken at 300 and 750 °C. G) and H) show the normalized radial profiles extracted from the integrated SAED patterns and subsequent radial intensity profile, respectively. I–L) In situ observation of copper dynamics during decreasing H₂/O₂ ratio from 10/1 to 5/1 at 500 °C.

Next, the researchers explored the influence of gas-phase composition on the structural dynamics, gradually decreasing the H₂/O₂ ratio from 10/1 to 5/1 at 500 °C. It was found that the relative increase of the oxygen partial pressure leads to a transformation of initially spherical nanoparticles into elongated particles with a head–tail structure. This is depicted in Figure 2I–L above. At the same time, the average particle size declines due to an increased rate of particle splitting, until a new size regime and dynamic equilibrium is established. Conclusively, the real-time observations under varying gas-phase composition and temperature show a clear effect of the gas-phase chemical potential on the average particle size. The in situ observations show clearly that redox dynamics make particles mobile, thereby considerably increasing the rate of sintering as compared to thermal sintering; yet the sintering under redox conditions is balanced by particle splitting, such that a certain size distribution is established as a function of reaction conditions.

“Controlled gas-flow and imaging – coupled with on-line mass spectroscopic analysis of the gas-phase composition as enabled by the Climate system – is essential for studies on the behavior of active catalyst and allows us to correlate observed structural and chemical dynamics to catalytic function.” – Dr. Marc-Georg Willinger, ETH Zurich

3) Relation between structural dynamics and catalytic activity

After investigating the gas-phase and temperature-induced dynamic processes, the researchers then sought out to explore the relationship between the observed structural dynamics and catalytic activity. The MS data is presented in Figure 3A) below, showing the formation of water and simultaneous consumption of oxygen. This ultimately confirms the catalytic activity of copper. A notable increase in water production and oxygen consumption is observed between 500 and 600°C, which is also the same range in which the intense structural dynamics occurred. In Figure 3B–D), the sequential HRTEM images of particle reshaping/restructuring at 550°C is presented (H₂/O₂ ratio of 10/1). This is also shown in the movie below. Although challenging, the researchers were still able to capture the thin oxide monolayer existing on the surface of the metallic portion of the particles (see Figure 3E,F). Interestingly, the surface oxide layer is observed even at 750°C. The structural features of the monolayer oxide imaged on various facets can be observed in Figure 3G,H).

Figure 3: Marc Willinger

Figure 3: Relation between structural dynamics of Cu and catalytic activity. A) shows the MS data collected at varied temperatures. B–D) show the sequential HRTEM images of particle reshaping/restructuring at 550°C. E,F) show the enlarged HRTEM images of the areas indicated by dashed rectangles in (B) and (D). G) shows an HRTEM image, and in H) an enlarged HRTEM image of the area indicated by the dotted rectangle in (G).

Movie 2: HRTEM movie showing particle reshaping and restructuring at 550°C

Methanol oxidation reaction on copper

After investigating the particle dynamics for hydrogen oxidation on copper, the researchers then set out to assess the generality of the phenomena described above. They first investigated the state of copper under conditions of methanol oxidation, a catalytic reaction that is relevant to industrial synthesis of formaldehyde. The figure below shows in situ TEM images of copper nanoparticles recorded at 600 and 500°C (Figure 4A–C and 4E–G), respectively. The dynamic behavior observed involves reshaping, sintering, and splitting of particles, similar to what was observed in the case of hydrogen oxidation. A shift to a more oxidized state with decreasing temperature was observed and verified by in situ SAED (Figure 4D,H). The redox dynamics are most pronounced at around 500°C under the chosen 1:1 ratio of MeOH and O₂.

Figure 4: Marc Willinger

Figure 4: Structural dynamics of Cu in methanol oxidation reaction. A–H) show TEM images and SAED patterns of Cu recorded in situ during methanol oxidation at 600 °C (A–D) and at 500 °C (E–H), respectively.

Methane oxidation reaction on palladium

Next, they investigated methane oxidation on palladium, a transition metal that is much harder to oxidize than copper. In the figure below, the structural dynamics related to catalytic activity in methane oxidation on palladium is presented. As in the case of copper, structural dynamics evolve when palladium is driven toward the Pd/PdO phase boundary. In an ~2:1 ratio of CH₄ and O₂, the catalyst remains relatively static at 350°C and shows coexistence of Pd and PdO as evinced by the in situ SAED. The system evolves to a highly dynamic state at 550°C. The MS data recorded simultaneously with TEM observation reveal a pronounced formation of CO₂ and consumption of CH₄ and O₂ under these conditions (see Figure 5I).

Figure 4: Marc Willinger

Figure 5: Structural dynamics related to catalytic activity in methane oxidation on Pd. A–H) In situ TEM images and SAED patterns of Pd recorded during methane oxidation at 350°C (A–D) and 550°C (E–H), respectively. I) shows the MS data recorded during in situ TEM observation of Pd in methane oxidation.

Conclusion

Via the above in situ studies of copper and palladium catalysts using our Climate system, the researchers show that catalytic activity goes hand-in-hand with redox processes of the metal catalyst. This paper evinces that the associated dynamics sensitively depend on reaction temperature and gas-phase composition. Importantly, only direct observation could reveal the interplay between metal and oxide phases and relate it to the onset of catalytic activity. This is precisely where our advanced in situ solutions come into play, enabling the direct observation of phenomena while it occurs. We are proud of the role that our Climate system has played in making this research possible and strive to continue enabling groundbreaking research in the future.

Hanglong Wu portrait

“The DENSsolutions Climate System allows us to reveal the so-far unseen: Looking at not only how the gas-phase is changed in the presence of a catalyst, but also studying how the interaction between gas-phase and catalyst leads to the emergence of catalytic function. Direct real-space observation is essential for our understanding of working catalysts and the development of new processes that are urgently needed in view of climate change and limited natural resources.”

Dr. Marc-Georg Willinger
Group Leader |  ETH Zurich

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DENSsolutions Climate system takes home the microscopy today 2021 innovation award

DENSsolutions’ Climate system takes home the Microscopy Today 2021 Innovation Award

DENSsolutions becomes a consecutive two-time winner of the Microscopy Today Innovation Awards. This year, our Climate system is recognized as one of the 10 most game-changing microscopy innovations of 2021.

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DENSsolutions’ Climate system takes home the Microscopy Today 2021 Innovation Award

DENSsolutions’ Climate system takes home the Microscopy Today 2021 Innovation Award

DENSsolutions becomes a consecutive two-time winner of the Microscopy Today Innovation Awards. This year, our Climate system is recognized as one of the 10 most game-changing microscopy innovations of 2021.

Just last year, our Stream system was awarded the Microscopy Today Innovation Award for its unique contribution to the field of liquid phase electron microscopy. We are honored to be taking home the same award for a second year in a row but this time for the remarkable innovation that is our Climate system. Climate is recognized as one of the 10 most game-changing microscopy innovations in 2021 by Microscopy Society of America‘s esteemed magazine, Microscopy Today. We interviewed our Chief Technology Officer Dr. Hugo Pérez-Garza, who led the development of the Climate system, to learn all about the unique benefits that made it earn such an esteemed award, as well as the development process and Climate’s current and envisioned applications. The transcript of the interview is provided below.

What was your reaction when you first heard the news?

It was pretty exciting. As you can imagine, the entire team was very happy when we first heard the news. At the end of the day, I think that this is just another consequence of the amazing teamwork that prevails in this company. And of course, to be accredited by the MSA is a big honor, especially as this is a highly esteemed award within the community. So it really means a lot to us. We really feel confident that our technology, and particularly our Climate system, will help scientists explore all sorts of new research possibilities.

What unique aspects of the system do you think made it earn such an esteemed award?

Over the last months, we have been exerting a lot of effort into making sure that we can improve the Climate system from various different angles. So that means that we have been doing a lot of work to ensure that we can optimize the different components that make up this plug-and-play system. Specifically, we have been trying to boost our MEMS capabilities (the Nano-Reactor). Moreover, we have been trying to continuously improve our hardware components, including the Gas Supply System, the Vaporizer, the Mass Spectrometer, etc. And of course, making sure that we can have new solutions as well for the software platform. Now when you put all these together, what we ended up realizing was that this new optimized Climate system brings all sort of real unique aspects to one’s research.

1) Live gas mixing

Firstly, Climate offers the possibility of performing live gas mixing (i.e. making sure that you can achieve any desired gas composition instantaneously). It ensures that users won’t have to wait for their gas mixtures to be prepared. We see this big added value in our customers’ experiments, for example in redox reactions, where the intrinsic nature of the experiment demands the possibility to quickly go from an oxidizing environment to a reducing environment. Often times people have to do this back-and-forth and in a fast and repetitive way. 

2) Start a new experiment (from a dry to wet environment or vice versa) within minutes

Furthermore, for these experiments a lot of researchers would be interested in humidifying the gas composition. This is precisely where the Vaporizer comes in. Now what happens here is that when you are humidifying the gas, often people are afraid of the contamination that the water molecules would represent for the gas lines. And that is why systems have to baked or have to undergo lengthy pumping times. But that wouldn’t be the case with the Vaporizer, as we have designed it in such a way that the introduction of the water vapor to the gas mixture is the last thing before entering the holder. So that ensures that your Gas Supply System will remain clean, and that you don’t have to perform these baking procedures or keep it pumping over night. This ultimately means you can go from a dry environment to a wet environment, or vice versa, in just a few minutes. So it opens up a lot of possibilities because it gives users this flexibility. 

3) Safely work with explosive mixtures and independently control gas parameters

The fact that we’re dealing with extremely low volumes of gas also means that we can safely handle explosive mixtures even if you plan to do this under extreme conditions such as high temperatures (above 1000°C) in combination with high pressures (i.e. 2 bars) and high relative humidity (i.e. 100%). Not only can you safely handle these explosive mixtures, but you can also control the relative humidity independently from other parameters such as temperature, pressure, gas composition and flow rate. So having this independent control also brings a lot of flexibility to users. 

4) Perform real nano-calorimetry and calibrate for time delay

The Nano-Reactor is also something very unique as we have been heavily optimizing the design such that, for example, the microheater allows for real nano-calorimetry. And this is really unique because it means that you can start quantifying and measuring the tiniest changes in temperature dissipation to understand if you’re observing an exothermic or endothermic reaction. And this is also really beneficial because you can calibrate for time delay, which is an issue that systems usually suffer from due to the unavoidable delay from the Gas Supply System to the MEMS device and to the Mass Spectrometer. Now, we can calibrate for that. 

5)  Prevent bypasses and achieve a desirable SNR

Moreover, the unique design of the Nano-Reactor itself, for which we have a patent, ensures that we can have an on-chip inlet and outlet. In other words, we can ensure that the gas will flow from the inlet to the outlet via the region of interest in a uni-directional way. And that means we can prevent bypasses and therefore improve the signal-to-noise ratio and the sensitivity of the Gas Analyzer. So the combination of these offerings (for example that our MEMS device can go to these high pressures like 2 bar, or allow you to perform EDS experiments well above 900 degrees at high pressures) ends up bringing a very unique value proposition for the user. 

What unique aspects of the system do you think made it earn such an esteemed award?

Over the last months, we have been exerting a lot of effort into making sure that we can improve the Climate system from various different angles. So that means that we have been doing a lot of work to ensure that we can optimize the different components that make up this plug-and-play system. Specifically, we have been trying to boost our MEMS capabilities (the Nano-Reactor). Moreover, we have been trying to continuously improve our hardware components, including the Gas Supply System, the Vaporizer, the Mass Spectrometer, etc. And of course, making sure that we can have new solutions as well for the software platform. Now when you put all these together, what we ended up realizing was that this new optimized Climate system brings all sort of real unique aspects to one’s research.

1) Live gas mixing

Firstly, Climate offers the possibility of performing live gas mixing (i.e. making sure that you can achieve any desired gas composition instantaneously). It ensures that users won’t have to wait for their gas mixtures to be prepared. We see this big added value in our customers’ experiments, for example in redox reactions, where the intrinsic nature of the experiment demands the possibility to quickly go from an oxidizing environment to a reducing environment. Often times people have to do this back-and-forth and in a fast and repetitive way. 

2) Start a new experiment (from a dry to wet environment or vice versa) within minutes

Furthermore, for these experiments a lot of researchers would be interested in humidifying the gas composition. This is precisely where the Vaporizer comes in. Now what happens here is that when you are humidifying the gas, often people are afraid of the contamination that the water molecules would represent for the gas lines. And that is why systems have to baked or have to undergo lengthy pumping times. But that wouldn’t be the case with the Vaporizer, as we have designed it in such a way that the introduction of the water vapor to the gas mixture is the last thing before entering the holder. So that ensures that your Gas Supply System will remain clean, and that you don’t have to perform these baking procedures or keep it pumping over night. This ultimately means you can go from a dry environment to a wet environment, or vice versa, in just a few minutes. So it opens up a lot of possibilities because it gives users this flexibility. 

3) Safely work with explosive mixtures and independently control gas parameters

The fact that we’re dealing with extremely low volumes of gas also means that we can safely handle explosive mixtures even if you plan to do this under extreme conditions such as high temperatures (above 1000°C) in combination with high pressures (i.e. 2 bars) and high relative humidity (i.e. 100%). Not only can you safely handle these explosive mixtures, but you can also control the relative humidity independently from other parameters such as temperature, pressure, gas composition and flow rate. So having this independent control also brings a lot of flexibility to users. 

4) Perform real nano-calorimetry and calibrate for time delay

The Nano-Reactor is also something very unique as we have been heavily optimizing the design such that, for example, the microheater allows for real nano-calorimetry. And this is really unique because it means that you can start quantifying and measuring the tiniest changes in temperature dissipation to understand if you’re observing an exothermic or endothermic reaction. And this is also really beneficial because you can calibrate for time delay, which is an issue that systems usually suffer from due to the unavoidable delay from the Gas Supply System to the MEMS device and to the Mass Spectrometer. Now, we can calibrate for that. 

5)  Prevent bypasses and achieve a desirable SNR

Moreover, the unique design of the Nano-Reactor itself, for which we have a patent, ensures that we can have an on-chip inlet and outlet. In other words, we can ensure that the gas will flow from the inlet to the outlet via the region of interest in a uni-directional way. And that means we can prevent bypasses and therefore improve the signal-to-noise ratio and the sensitivity of the Gas Analyzer. So the combination of these offerings (for example that our MEMS device can go to these high pressures like 2 bar, or allow you to perform EDS experiments well above 900 degrees at high pressures) ends up bringing a very unique value proposition for the user. 

What inspired you and the entire team to develop Climate in the first place?

Certainly understanding the importance and the impact that environmental studies can have on our global society was a big source of inspiration for the entire team. Having said that, understanding the solid-gas interactions at the nanoscale is what sets the foundation such that scientists can really start understanding how to optimize and synthesize future catalytic nanoparticles, which will end up playing a crucial role in applications such as carbon capture, energy storage and conversion as well as food production. So it is really this profound information that we can get from in situ TEM that gives this understanding. Because when you can start correlating particle size with composition, crystal orientation, or with the atomic or the electronic structure, it really gives a deep level of understanding for all these kinds of experiments. 

Can you walk us through the development process of Climate?

It has been 5 or 6 years since we launched our first product line for in situ gas analysis. Ever since, what we have been doing is trying to make sure that we can stay as close as we can to our customers as well as prospects. Now the intention of doing that is when you start gathering the feedback and the vision that both groups have, you start understanding the pain points a little bit more. You start becoming more empathic to their experimental needs. And that helps us identify the product profile that we should have in place. And when you are aware of this product profile, then automatically you know what technologies must be developed, which is part of your roadmap. And subsequently when you have that in place, then you also know what people and processes must be involved. So, it’s a matter of doing that so that when we gather these market requirements, we can follow a defined product creation process that will allow us to develop a technology that will match these market requirements. 

What future applications do you envision for Climate?

Certainly everything related to green technologies. As I mentioned earlier, that is a big goal and motivation that we all have at this company. So these kinds of experiments and topics I was referring to like carbon capture, energy conversion and storage, and all sort of environmental protection kind of studies, that’s really where everything will head towards. 

Thank you for reading. To learn more about our Climate system please follow the links below.

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