J. Mater. Sci. Technol. ›› 2025, Vol. 218: 1-24.DOI: 10.1016/j.jmst.2024.08.029

• Review Article •     Next Articles

Understanding oxidation state of Cu-based catalysts for electrocatalytic CO2 reduction

Ping Zhua, Yuan-Chu Qina, Xin-Hao Caia, Wen-Min Wanga, Ying Zhoub, Lin-Lin Zhouc, Peng-Hui Liua, Lu Penga, Wen-Long Wanga, Qian-Yuan Wua,*   

  1. aShenzhen Key Laboratory of Ecological Remediation and Carbon Sequestration, Environmental Protection Key Laboratory of Microorganism Application and Risk Control, Institute of Environment and Ecology, Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China;
    bDepartment of Materials Science and Technology, University of Science and Technology of China, Hefei 230026, China;
    cCollege of Chemistry, Beijing University of Chemical Technology, Beijing 100029, China
  • Received:2024-04-25 Revised:2024-07-24 Accepted:2024-08-27 Published:2025-05-20 Online:2024-09-07
  • Contact: *E-mail address: wu.qianyuan@sz.tsinghua.edu.cn (Q.-Y. Wu).

Abstract: Electrocatalytic CO2 reduction (ECR) is a promising approach for achieving carbon neutrality due to its ability to convert CO2 to valuable chemicals. Recent advances have significantly enhanced the ECR performance of various catalysts by tuning their oxidation states, particularly for Cu-based catalysts that can reduce CO2 to multiple products. However, the oxidation state of copper (OSCu), especially Cu+, changes during the reaction process, posing significant challenges for both catalyst characterization and performance. In this review, the current understanding of the effect of oxidation states on product selectivity was first discussed. A comprehensive overview of in situ/operando characterization techniques, used to monitor the dynamic evolution of oxidation states during ECR, was then provided. Various strategies for stabilizing oxidation states through modification of catalysts and manipulation of external conditions were discussed. This review aimed to deepen the understanding of oxidation states in ECR and enlighten the development of more efficient electrocatalysts.

Key words: Electrocatalytic CO2 reduction, Cu-based catalysts, Oxidation state, In situ/operando characterization techniques, Stabilization strategies