Real‐Time Imaging of Nanoscale Redox Reactions over Bimetallic Nanoparticles
Shu Fen Tan See Wee Chee Zhaslan Baraissov Hongmei Jin Teck Leong Tan Utkur Mirsaidov
Published in Advanced Functional Materials on 16 July 2019
Video 1: In situ TEM movie of a Pt–Ni rhombic dodecahedron NP undergoing oxidation reaction in 20% O2 / 80% N2 gaseous environment at 400 °C inside a gas cell.
Video 2: In situ TEM movie of a Pt–Ni rhombic dodecahedron NP undergoing reduction reaction in 5% H2 / 95% N2 gaseous environment at 400 °C inside a gas cell.
This recent article from National University of Singapore about the catalyst activity of bimetalic nanoparticles clearly demonstrates the versatility of the Climate G+ gas & heating system that was used for the in situ TEM experiments.
Figure S4. In situ TEM images showing the evolution of Pt–Ni NPs (A) before and (B) after the oxidation (20% O2 / 80% N2) reaction followed by (C) the reduction (5% H2 / 95% N2) reaction at 400 °C inside a gas cell. Here, t = 0 s marks the start of 20% O2 / 80% N2 flow. At t = 133.1 s, the gas mixture was switched to 5% H2 / 95% N2.
Fast switching between oxidizing and reducing gas conditions allows direct observation of the morphological changes in the catalyst material. The video’s above also demonstrate the UHR image stability at in situ conditions.
Combining the images and video’s from this experiment with SAED, EDS and Mass Spectroscopy results gives valuable information about the areas where the catalyst is most active.