Volume 62, Issue 8 e202218167
Research Article

Tuning the CO2 Hydrogenation Selectivity of Rhodium Single-Atom Catalysts on Zirconium Dioxide with Alkali Ions

Shang Li

Shang Li

Department of Chemical Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026 China

These authors contributed equally to this work.

Search for more papers by this author
Yuxing Xu

Yuxing Xu

Department of Chemical Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026 China

These authors contributed equally to this work.

Search for more papers by this author
Dr. Hengwei Wang

Corresponding Author

Dr. Hengwei Wang

Department of Chemical Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026 China

Search for more papers by this author
Prof. Botao Teng

Prof. Botao Teng

Tianjin Key Laboratory of Brine Chemical Engineering and Resource Eco-utilization, College of Chemical Engineering and Materials Science, Tianjin University of Science and Technology, Tianjin, 300457 China

Search for more papers by this author
Dr. Qin Liu

Dr. Qin Liu

Department of Chemical Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026 China

Search for more papers by this author
Dr. Qiuhua Li

Dr. Qiuhua Li

Department of Chemical Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026 China

Search for more papers by this author
Lulu Xu

Lulu Xu

Department of Chemical Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026 China

Search for more papers by this author
Xinyu Liu

Xinyu Liu

Department of Chemical Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026 China

Search for more papers by this author
Prof. Junling Lu

Corresponding Author

Prof. Junling Lu

Department of Chemical Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026 China

Search for more papers by this author
First published: 27 December 2022
Citations: 20

Graphical Abstract

Doping alkali ions (e.g., Na) into Rh1/ZrO2 enables complete switching of the reaction product from CH4 to CO in CO2 hydrogenation over a broad temperature range. It was found that Na+ ions change the surface intermediate from HCOO* to COOH* and render the Rh1 atoms electron deficient with restrained H2 activation capability and weakened CO adsorption, thus cooperatively boosting CO formation.

Abstract

Tuning the coordination environments of metal single atoms (M1) in single-atom catalysts has shown large impacts on catalytic activity and stability but often barely on selectivity in thermocatalysis. Here, we report that simultaneously regulating both Rh1 atoms and ZrO2 support with alkali ions (e.g., Na) enables efficient switching of the reaction products from nearly 100 % CH4 to above 99 % CO in CO2 hydrogenation in a wide temperature range (240–440 °C) along with a record high activity of 9.4 molCO gRh−1 h−1 at 300 °C and long-term stability. In situ spectroscopic characterization and theoretical calculations unveil that alkali ions on ZrO2 change the surface intermediate from formate to carboxy species during CO2 activation, thus leading to exclusive CO formation. Meanwhile, alkali ions also reinforce the electronic Rh1-support interactions, endowing the Rh1 atoms more electron deficient, which improves the stability against sintering and inhibits deep hydrogenation of CO to CH4.

Conflict of interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.