Chinese Journal of Catalysis ›› 2021, Vol. 42 ›› Issue (9): 1500-1508.DOI: 10.1016/S1872-2067(20)63754-8

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Tuning the intermediate reaction barriers by a CuPd catalyst to improve the selectivity of CO2 electroreduction to C2 products

Li Zhua, Yiyang Lina, Kang Liua, Emiliano Cortésb, Hongmei Lia, Junhua Huc, Akira Yamaguchid, Xiaoliang Liua,#(), Masahiro Miyauchid,$(), Junwei Fua,(), Min Liua,*()   

  1. aShenzhen Research Institute, School of Physics and Electronics, Central South University, Changsha 410083, Hunan, China
    bChair in Hybrid Nanosystems, Nanoinstitute Munich, Faculty of Physics, Ludwig-Maximilians-Universität München, 80539 München, Germany
    cSchool of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450052, Henan, China
    dDepartment of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Tokyo 152-8552, Japan
  • Received:2020-11-18 Accepted:2020-12-09 Online:2021-09-18 Published:2021-05-16
  • Contact: Xiaoliang Liu,Masahiro Miyauchi,Junwei Fu,Min Liu
  • About author: E-mail: fujunwei@csu.edu.cn
    $ E-mail: mmiyauchi@ceram.titech.ac.jp;
    # E-mail: xl_liu@csu.edu.cn;
    * Tel: +86-13787082527; E-mail: minliu@csu.edu.cn;
  • Supported by:
    Natural Science Foundation of China(21872174);Natural Science Foundation of China(22002189);Natural Science Foundation of China(51673217);Natural Science Foundation of China(U1932148);International Science and Technology Cooperation Program(2017YFE0127800);International Science and Technology Cooperation Program(2018YFE0203402);Hunan Provincial Science and Technology Program(2017XK2026);Hunan Provincial Natural Science Foundation(2020JJ2041);Hunan Provincial Natural Science Foundation(2020JJ5691);Hunan Provincial Science and Technology Plan Project(2017TP1001);Shenzhen Science and Technology Innovation Project(JCYJ20180307151313532)

Abstract:

Electrochemical CO2 reduction is a promising strategy for the utilization of CO2 and intermittent excess electricity. Cu is the only single metal catalyst that can electrochemically convert CO2 into multicarbon products. However, Cu exhibits an unfavorable activity and selectivity for the generation of C2 products because of the insufficient amount of CO* provided for the C-C coupling. Based on the strong CO2 adsorption and ultrafast reaction kinetics of CO* formation on Pd, an intimate CuPd(100) interface was designed to lower the intermediate reaction barriers and improve the efficiency of C2 product formation. Density functional theory (DFT) calculations showed that the CuPd(100) interface enhanced the CO2 adsorption and decreased the CO2* hydrogenation energy barrier, which was beneficial for the C-C coupling. The potential-determining step (PDS) barrier of CO2 to C2 products on the CuPd(100) interface was 0.61 eV, which was lower than that on Cu(100) (0.72 eV). Encouraged by the DFT calculation results, the CuPd(100) interface catalyst was prepared by a facile chemical solution method and characterized by transmission electron microscopy. CO2 temperature-programmed desorption and gas sensor experiments further confirmed the enhancement of the CO2 adsorption and CO2* hydrogenation ability of the CuPd(100) interface catalyst. Specifically, the obtained CuPd(100) interface catalyst exhibited a C2 Faradaic efficiency of 50.3% ± 1.2% at ‒1.4 VRHE in 0.1 M KHCO3, which was 2.1 times higher than that of the Cu catalyst (23.6% ± 1.5%). This study provides the basis for the rational design of Cu-based electrocatalysts for the generation of multicarbon products by fine-tuning the intermediate reaction barriers.

Key words: Carbon dioxide reduction, C2 products, Electrocatalyst, Copper-palladium interface, Intermediate reaction barriers