CatalysisOperando TEM Catalysis at atmospheric pressure

Atomistic interaction of gas-solid phase is important to understand the working mechanism of various catalyst materials. This is specially for heterostructures with different structures. Researchers at Argonne National Laboratory used Hummingbird Scientific’s Gas TEM system and observed atomic interaction of Ag/AgCl heterostructures during the redox process using the beam. In the experiment, Ag/AgCl nanocatalyst was first reduced to Ag, and then Ag was oxidized to different phases of silver oxide under different O2 partial pressures. Ag2O formed at low O2 partial pressure, whereas AgO formed at atmospheric pressure.

The TEM image of the top left shows the atomic scale redox dynamics of Ag/AgCl heterostructures studied using in-situ TEM gas holder.

Reference: Yimin A. Wu, Liang Li, Zheng Li, Alper Kinaci, Maria K. Y. Chan, Yugang Sun, Jeffrey R. Guest, Ian McNulty, Tijana Rajh, and Yuzi Liu. “Visualizing Redox Dynamics of a Single Ag/AgCl Heterogeneous Nanocatalyst at Atomic Resolution,” ACS Nano (2016) pp. 3738-3746. Abstract

Image copyright © 2016 American Chemical Society

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