Journal of Energy Chemistry ›› 2023, Vol. 79 ›› Issue (4): 312-320.DOI: 10.1016/j.jechem.2022.11.058

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Achieving highly selective electrochemical CO2 reduction to C2H4 on Cu nanosheets

Huan Xiea,b,1, Ruikuan Xiea,1, Zhiyuan Zhangc, Yongyu Panga,d, Yuting Luoc, Jiong Lie, Bilu Liuc, Maria-Magdalena Titiricif, Guoliang Chaia,d,*   

  1. aState Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, Fujian, China;
    bJiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, International Innovation Center for Forest Chemicals and Materials, College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, Jiangsu, China;
    cShenzhen Geim Graphene Center (SGC), Tsinghua-Berkeley Shenzhen Institute (TBSI) and Tsinghua Shenzhen International Graduate School (TSIGS), Tsinghua University, Shenzhen 518055, Guangdong, China;
    dSchool of Chemical Science, University of Chinese Academy of Sciences, Beijing 100049, China;
    eShanghai Synchrotron Radiation Facility Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China;
    fDepartment of Chemical Engineering, Imperial College London, SW7 2AZ, UK
  • Received:2022-08-09 Revised:2022-11-30 Accepted:2022-11-30 Online:2023-04-15 Published:2023-05-30
  • Contact: * E-mail address: g.chai@fjirsm.ac.cn (G. Chai).
  • About author:1These authors contributed equally to this work.

Abstract: The conversion of CO2 into value-added chemicals coupled with the storage of intermittent renewable electricity is attractive. CuO nanosheets with an average size and thickness of ~ 30 and ~ 20 nm have been developed, which are in situ reduced into Cu nanosheets during electrochemical CO2 reduction reac-tion (ECO2RR). The derived Cu nanosheets demonstrate much higher selectivity for C2H4 production than commercial CuO derived Cu powder, with an optimum Faradaic efficiency of 56.2% and a partial current density of C2H4 as large as 171.0 mA cm-2 in a gas diffusion flow cell. The operando attenuated total reflectance-Fourier transform infrared spectra measurements and density functional theory simulations illustrate that the high activity and selectivity of Cu nanosheets originate from the edge sites on Cu nanosheets with a coordinate number around 5 (4-6), which facilitates the formation of *CHO rather than *COH intermediate, meanwhile boosting the C—C coupling reaction of *CO and *CHO intermediates, which are the critical steps for C2H4 formation.

Key words: Electrochemical CO2 reduction, Cu nanosheets, C2H4, High selectivity, Coordination number