CO2 Hydrogenation over Copper/ZnO Single-Atom Catalysts: Water-Promoted Transient Synthesis of Methanol

Wenlong Wu; Yanan Wang; Lei Luo; Menglin Wang; Zhongling Li; Yue Chen; Zhiqi Wang; Jingbo Chai; Zeyan Cen; Yongliang Shi; Jin Zhao; Jie Zeng; Hongliang Li

doi:10.1002/anie.202213024

CO₂ Hydrogenation over Copper/ZnO Single-Atom Catalysts: Water-Promoted Transient Synthesis of Methanol

Angew Chem Int Ed Engl. 2022 Nov 25;61(48):e202213024. doi: 10.1002/anie.202213024. Epub 2022 Oct 27.

Authors

Wenlong Wu¹, Yanan Wang^{1

2

3}, Lei Luo¹, Menglin Wang¹, Zhongling Li¹, Yue Chen¹, Zhiqi Wang¹, Jingbo Chai¹, Zeyan Cen¹, Yongliang Shi^{1

4}, Jin Zhao¹, Jie Zeng¹, Hongliang Li¹

Affiliations

¹ Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, National Synchrotron Radiation Laboratory, Department of Chemical Physics, Department of Physics, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
² Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, P. R. China.
³ Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, P. R. China.
⁴ Center for Spintronics and Quantum Systems, State Key Laboratory for Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi'an Jiaotong University Xi'an, Shanxi, 710049, P. R. China.

PMID: 36173974
DOI: 10.1002/anie.202213024

Abstract

The hydrogenation of CO₂ by renewable power-generated hydrogen offers a promising approach to a sustainable carbon cycle. However, the role of water during CO₂ hydrogenation is still under debate. Herein, we demonstrated that either too low or too high contents of water hampered the methanol synthesis over Cu/ZnO based catalysts. For Cu single atoms on ZnO supports, the optimal content of water was 0.11 vol. % under 30 bar (CO₂ : H₂ =1 : 3) at 170 °C. Upon the introduction of optimal-content water, the methanol selectivity immediately became 99.1 %, meanwhile the conversion of CO₂ underwent a volcano-type trend with the maximum of 4.9 %. According to mechanistic studies, water acted as a bridge between H atoms and CO₂ /intermediates, facilitating the transformation of COOH* and CH₂ O*. The enhanced activity induced the generation of more water to react with CO via water-gas shift reaction, resulting in the increase in methanol selectivity.

Keywords: CO2; Cu/ZnO; Methanol; Single-Atom Catalysis; Water.

Abstract

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