Structure-activity relationship of Cu-based catalysts for the highly efficient CO2 electrochemical reduction reaction

Runzhi An; Xuanqi Chen; Qi Fang; Yuxiao Meng; Xi Li; Yongyong Cao

doi:10.3389/fchem.2023.1141453

Structure-activity relationship of Cu-based catalysts for the highly efficient CO₂ electrochemical reduction reaction

Front Chem. 2023 Feb 9:11:1141453. doi: 10.3389/fchem.2023.1141453. eCollection 2023.

Authors

Runzhi An¹, Xuanqi Chen¹, Qi Fang¹, Yuxiao Meng^{1

2}, Xi Li¹, Yongyong Cao¹

Affiliations

¹ College of Biological, Chemical Science and Engineering, Jiaxing University, Jiaxing, Zhejiang, China.
² College of Chemical Engineering, State Key Laboratory Breeding Base of Green-Chemical Synthesis Technology, Zhejiang University of Technology, Hangzhou, China.

Abstract

Electrocatalytic carbon dioxide reduction (CO₂RR) is a relatively feasible method to reduce the atmospheric concentration of CO₂. Although a series of metal-based catalysts have gained interest for CO₂RR, understanding the structure-activity relationship for Cu-based catalysts remains a great challenge. Herein, three Cu-based catalysts with different sizes and compositions (Cu@CNTs, Cu₄@CNTs, and CuNi₃@CNTs) were designed to explore this relationship by density functional theory (DFT). The calculation results show a higher degree of CO₂ molecule activation on CuNi₃@CNTs compared to that on Cu@CNTs and Cu₄@CNTs. The methane (CH₄) molecule is produced on both Cu@CNTs and CuNi₃@CNTs, while carbon monoxide (CO) is synthesized on Cu₄@CNTs. The Cu@CNTs showed higher activity for CH₄ production with a low overpotential value of 0.36 V compared to CuNi₃@CNTs (0.60 V), with *CHO formation considered the potential-determining step (PDS). The overpotential value was only 0.02 V for *CO formation on the Cu₄@CNTs, and *COOH formation was the PDS. The limiting potential difference analysis with the hydrogen evolution reaction (HER) indicated that the Cu@CNTs exhibited the highest selectivity of CH₄ among the three catalysts. Therefore, the sizes and compositions of Cu-based catalysts greatly influence CO₂RR activity and selectivity. This study provides an innovative insight into the theoretical explanation of the origin of the size and composition effects to inform the design of highly efficient electrocatalysts.

Keywords: Cu-based catalysts; compositional effect; density functional theory (DFT); electrochemical CO2 reduction reaction (CO2RR); size effect.

Grants and funding

This work is financially supported by the National Natural Science Foundation of China (grant no. 22108093), the National Key Research and Development Program of China (grant no. 2018YFB1502900), the Natural Science Foundation of Zhejiang Province (grant nos. LY19B060006 and LQ20E030016), and the Innovation Jiaxxing Elite Leadership Plan and Technology Development Project of Jiaxing University (70518040).