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Real‐Time Atomic‐Scale Visualization of Reversible Copper Surface Activation during the CO Oxidation Reaction
Author(s) -
Luo Langli,
Nian Yao,
Wang Shuangbao,
Dong Zejian,
He Yang,
Han You,
Wang Chongmin
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201915024
Subject(s) - metastability , copper , catalysis , chemistry , atomic units , transmission electron microscopy , phase (matter) , amorphous solid , crystallography , chemical physics , photochemistry , materials science , nanotechnology , biochemistry , physics , organic chemistry , quantum mechanics
By using in situ aberration‐corrected environmental transmission electron microscopy, for the first time at atomic level, the dynamic evolution of the Cu surface is captured during CO oxidation. Under reaction conditions, the Cu surface is activated, typically involving 2–3 atomic layers with the formation of a reversible metastable phase that only exists during catalytic reactions. The distinctive role of CO and O 2 in the surface activation is revealed, which features CO exposure to lead to surface roughening and consequently formation of low‐coordinated Cu atoms, while O 2 exposure induces a quasi‐crystalline CuOx phase. Supported by DFT calculations, it is shown that crystalline CuOx reversibly transforms into the amorphous phase, acting as an active species to facilitate the interaction of gas reactants and catalyzing CO oxidation.