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Atomic Origin of the Autocatalytic Reduction of Monoclinic CuO in a Hydrogen Atmosphere



Xianhu Sun, Dongxiang Wu, Wenhui Zhu, Xiaobo Chen, Renu Sharma, Judith Yang, Guangwen Zhou


Reducibility is a prerequisite for the use of bulk metal oxides in chemical transformation 17 involving redox reactions but probing microscopic processes of oxide reduction is challenging as 18 the insulating nature of bulk oxides restricts ion and electron spectroscopic measurements of oxide 19 surfaces. Herein, using a combination of environmental transmission electron microscopy and 20 atomistic modeling, we report direct in-situ atomic-scale observations of the surface and 21 subsurface dynamics and show that the hydrogen induced CuO reduction occurs via the surface 22 decay of Cu-O/Cu bilayer atomic steps, formation of partially reduced CuO superstructure by the 23 self-ordering of O vacancies in the subsurface, and collapse of Cu-O layers in the bulk. All these 24 substeps can be traced back to the progressively increased concentration and activity of O 25 vacancies in the surface and subsurface of the oxide, thereby leading to the self-accelerated oxide 26 reduction. These results demonstrate the microscopic details that may have broader applicability 27 in modulating various redox processes.
The Journal of Physical Chemistry Letters


Autocatalysis, In situ Environmental TEM, Copper oxide, Redox reaction


Sun, X. , WU, D. , Zhu, W. , Chen, X. , Sharma, R. , Yang, J. and Zhou, G. (2021), Atomic Origin of the Autocatalytic Reduction of Monoclinic CuO in a Hydrogen Atmosphere, The Journal of Physical Chemistry Letters, [online],, (Accessed June 20, 2024)


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Created September 27, 2021, Updated November 29, 2022