Enhanced electrochemical CO 2 -to-ethylene conversion through second-shell coordination on a Cu single-atom catalyst

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2024-04, Vol.12 (15), p.9075-9087
• Main Authors: Shen, Yi, Pan, Yongliang, Xiao, Huanyong, Zhang, Haizhong, Zhu, Chao, Fang, Qile, Li, Yungui, Lu, Lun, Ye, Liqun, Song, Shuang
• Format: Article
• Language: English
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/D3TA08073K

Electrocatalytic reduction of carbon dioxide (CO 2 RR) to C 2+ products presents an ideal approach to mitigate the continuous accumulation of CO 2 for achieving carbon neutrality. However, the selectivity for C 2+ products is constrained by the high energy barrier associated with C–C coupling and the sluggishness of multiple proton-coupled electron transfer (PCET), resulting in reduced efficiency and selectivity. Herein, a single-atom Cu catalyst with second-shell S coordination (Cu–C 3 N 4 –S) is prepared, exhibiting higher ethylene (C 2 H 4 ) faradaic efficiency (60.2% at −0.9 V vs. RHE). The second-shell S doping structure is confirmed using a DFT theoretical model combined with synchrotron X-ray absorption spectroscopy. Simultaneously, the adsorption of *CO 2 intermediates is detected by in situ Raman spectroscopy, allowing for the inference of potential reaction pathways. It is confirmed that through the regulation of second-shell S doping, a notable reduction in the energy barrier of C–C coupling ensues, concurrently tackling the electron demand in the PECT reaction via the construction of an electron transfer pathway (S–N–Cu) at a lower overpotential. This study contributes novel insights to the design of atomic-sized copper-based catalysts inspired by the indirect coordination and heteroatom regulation technique.