Chinese Journal of Catalysis ›› 2026, Vol. 87: 47-58.DOI: 10.1016/S1872-2067(26)65092-9

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Neighboring Ni-Cu dual single-atom sites regulate the local environment of interfacial water for promoting CO2 electroreduction kinetics in CO2-to-CO conversion

Qi Haoa,b,1, Qi Tangc,d,1, Junxiu Wue, Kai Liub,f,*(), Jun Lue,*(), Tianpin Wue,*()   

  1. a School of Materials Science & Engineering, Zhejiang University, Hangzhou 310027, Zhejiang, China
    b School of Engineering, Westlake University, Hangzhou 310030, Zhejiang, China
    c State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Jilin, China
    d School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, Anhui, China
    e College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, Zhejiang, China
    f Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou 310030, Zhejiang, China
  • Received:2025-11-09 Accepted:2026-02-04 Online:2026-08-18 Published:2026-06-24
  • About author:1Contributed equally to this work.
  • Supported by:
    Westlake-Muyuan Institute of Synthetic Biology(N14116522401);Westlake Education Foundation(103506022001);Leading Innovative and Entrepreneurial Projects in Zhejiang Province(2023R01007)

Abstract:

We develop a Ni-Cu dual single-atom catalyst (DSAC) as a model catalyst to investigate the neighboring synergy in dual single-atom sites for promoting the electrocatalytic carbon dioxide reduction reaction (ECO2RR) kinetics. Through detailed electrochemical tests, in situ spectroscopic observations and theoretical calculations, we found that during ECO2RR, the neighboring Ni-Cu dual single-atom sites synergistically weaken the rigidity of the hydrogen-bond networks of interfacial water and optimize the spatial configuration of water molecules surrounding the Ni-Cu dual single-atom sites, which increases the proportion of easily dissociated water species in the interfacial water, thus accelerating the CO2 protonation kinetics during the conversion of CO2 to CO. As a result, Ni-Cu DSAC exhibits a 1.5-fold increase and a 15-fold increase in ECO2RR activity compared to Ni SAC and Cu SAC, respectively. In flow cell electrolyzer, Ni-Cu DSAC achieves almost 100% Faradaic efficiency for CO production (FECO) from applied current density of 50 to 400 mA cm−2, with the optimal full-cell energy efficiency of 61.1% for CO production, reflecting the excellent catalytic performance of neighboring Ni-Cu dual single-atom sites for selective conversion of CO2 to CO. Benefiting from the efficient suppression of carbonates formation in acidic media, Ni-Cu DSAC achieves an outstanding single-pass carbon efficiency of 67.3% for CO2-to-CO conversion at 200 mA cm−2. Additionally, Ni-Cu DSAC also exhibits excellent long-term stability, with less than 10% decay of FECO throughout a 170-h continuous electrolysis in strong acid (pH = 1, j = 200 mA cm−2).

Key words: CO2 electroreduction, Neighboring synergistic effect, Microenvironment regulation, Optimized CO2 protonation kinetics, Industrial-level current densities