Volume 137, Issue 30 e202502834
Zuschrift

Dynamic Crystal-Structure and Active-Site of Defective ZnAl-Catalysts During CO2 Photoreduction

Zhengchao Wang

Zhengchao Wang

State Key Laboratory for Oxo Synthesis and Selective Oxidation, National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 P.R. China

University of Chinese Academy of Sciences, Beijing, 100049 P.R. China

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Prof. Rongsheng Cai

Prof. Rongsheng Cai

State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 P.R. China

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Dr. Yajun Zhang

Corresponding Author

Dr. Yajun Zhang

State Key Laboratory for Oxo Synthesis and Selective Oxidation, National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 P.R. China

E-mail: [email protected]; [email protected]

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Xiaojuan Huang

Xiaojuan Huang

State Key Laboratory for Oxo Synthesis and Selective Oxidation, National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 P.R. China

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Prof. Yingpu Bi

Corresponding Author

Prof. Yingpu Bi

State Key Laboratory for Oxo Synthesis and Selective Oxidation, National Engineering Research Center for Fine Petrochemical Intermediates, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000 P.R. China

E-mail: [email protected]; [email protected]

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First published: 15 May 2025

Abstract

Understanding of surface defects of a catalyst during the reaction process is critical to establish an accurate structure-activity relationship. Herein, combining operando X-ray diffraction/photoelectron spectroscopy with scanning probe microscope, we have first established the correlations between CO2 photoreduction activities and crystal-structure/active-site of defective ZnAl layered double hydroxides (ZnAl-LDH). Specifically, the introduction of oxygen vacancies in ZnAl-LDH could effectively promote the selective adsorption of both CO2 and H2O molecules on surface Al and Zn active sites, respectively, leading to opposite transition states and the evident shrinking of crystalline structures. Under light irradiation, the adsorbed CO2 molecules transformed into *COOH intermediate on surface Al active sites, while the H2O molecules dissociated into OH group on Zn sites to provide proton, simultaneously leading to the expansion of crystalline structures and increase of layer spacing. Accordingly, these defect-dependent evolutions of surface active sites and crystalline structure contributed to the significant improvement of CO2 reduction to CO activity (17.2 µmol g−1 h−1), much higher than that of pristine ZnAl-LDH (6.3 µmol g−1 h−1). This work provides new insights for in-depth understanding of the electronic and crystalline changes of defective photocatalysts during the reaction process.

Conflict of Interests

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available in the Supporting Information of this article.

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