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

Published

September 27, 2021

Author(s)

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

Abstract

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.

Citation

The Journal of Physical Chemistry Letters

Volume

12

Issue

39

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acs.jpclett.1c02369

Local Download

Keywords

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

Citation

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], https://doi.org/10.1021/acs.jpclett.1c02369, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=932403 (Accessed April 25, 2024)