Acta Phys. -Chim. Sin. ›› 2023, Vol. 39 ›› Issue (2): 2207026.doi: 10.3866/PKU.WHXB202207026

• ARTICLE • Previous Articles     Next Articles

Oxygen Vacancy-Rich Amorphous Copper Oxide Enables Highly Selective Electroreduction of Carbon Dioxide to Ethylene

Tianran Wei1, Shusheng Zhang2, Qian Liu3, Yuan Qiu4, Jun Luo4,5, Xijun Liu1,*()   

  1. 1 MOE Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials, and Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured Materials, School of Resource, Environments and Materials, Guangxi University, Nanning 530004, China
    2 College of Chemistry, Zhengzhou University, Zhengzhou 450000, China
    3 Institute for Advanced Study, Chengdu University, Chengdu 610106, China
    4 Shenzhen Institute for Advanced Study, University of Electronic Science and Technology of China, Shenzhen 518110, Guangdong Province, China
    5 Institute for New Energy Materials and Low-Carbon Technologies, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China
  • Received:2022-07-12 Accepted:2022-09-08 Published:2022-09-15
  • Contact: Xijun Liu
  • About author:Xijun Liu, Email:
  • Supported by:
    the National Natural Science Foundation of China(22075211);the National Natural Science Foundation of China(21601136);the National Natural Science Foundation of China(51971157);the National Natural Science Foundation of China(51621003);Tianjin Science Fund for Distinguished Young Scholars(19JCJQJC61800)


The ever-increasing carbon dioxide (CO2) emissions caused by excessive fossil fuel consumption induce environmental issues such as global warming. To overcome this, the electrocatalytic CO2 reduction (ECR) under ambient conditions offers an appealing approach for converting CO2 to value-added chemicals and realizing a closed carbon loop. Among the ECR products, ethylene (C2H4), an important building block for plastics and other chemicals, has attracted considerable attention owing to its compatibility with existing infrastructure and the promising substitution of industrial steam cracking. In recent years, numerous efforts have been devoted to developing highly active and selective catalysts for converting CO2 to C2H4, with most studies having focused on Cu-based materials. Despite the significant advancements made to date, the development of the ECR-to-C2H4 process is still hindered by the lack of suitable catalysts that can effectively activate CO2 and strengthen the surface binding of *CO and *COH species. In this study, an amorphous copper oxide (CuOx) nanofilm that is rich in oxygen vacancies was prepared via a facile vacuum evaporation method for the efficient electrocatalytic conversion of CO2 to C2H4. It was expected that the nano-scale electrode thickness would greatly accelerate charge- and mass-transfer during CO2 electrolysis. Moreover, the introduction of oxygen vacancies favored the adsorption of CO2 and intermediates. As a result, in a typical H-cell, the synthesized defective catalyst delivered a maximum Faradaic efficiency of 85 ± 3% at −1.3 V versus the reversible hydrogen electrode and maintained a stable C2H4 selectivity over 48 h in a 0.1 M potassium bicarbonate solution. Interestingly, the performance observed with the synthesized electrocatalyst in this study is comparable with that of state-of-the-art Cu-based ECR catalysts. Additional structural and chemical characterizations confirmed the robust nature of the as-prepared catalyst. Moreover, when the catalyst was utilized in a membrane electrode assembly cell, it achieved a maximum C2H4 partial current density of approximately 115.4 mA∙cm−2 at a cell voltage of −1.95 V and Faradaic efficiency of 78 ± 2% at a cell voltage of −1.75 V. Furthermore, theoretical and experimental analyses revealed that oxygen defects not only favored CO2 adsorption but also enabled strong affinities for *CO and *COH intermediates, which synergistically contributed to a high selectivity for C2H4 formation. We believe that our present work will motivate the exploration of amorphous Cu-based materials for achieving efficient CO2-to-C2H4 electrolysis and be a guide towards fundamentally understanding the mechanism of catalytic CO2 reduction.

Key words: CO2 fixation, C2 product, Electrocatalysis, Amorphous catalyst, Cu oxide