Unveiling the Proton-Feeding Effect in Sulfur-Doped Fe-N-C Single-Atom Catalyst for Enhanced CO2 Electroreduction

作者：Chen, Shanyong; Li, Xiaoqing; Kao, Cheng-Wei; Luo, Tao; Chen, Kejun; Fu, Junwei; Ma, Chao; Li, Hongmei; Li, Ming; Chan, Ting-Shan^*; Liu, Min^*

来源：Angewandte Chemie - International Edition, 2022, 61(32): e202206233.

DOI：10.1002/anie.202206233

• CO2 Electroreduction
• Heteroatom Doping
• Proton-Feeding Effect
• Reaction Kinetics
• Single-Atom Catalysts

Heteroatom-doping in metal-nitrogen-carbon single-atom catalysts (SACs) is considered a powerful strategy to promote the electrocatalytic CO2 reduction reaction (CO2RR), but the origin of enhanced catalytic activity is still elusive. Here, we disclose that sulfur doping induces an obvious proton-feeding effect for CO2RR. The model SAC catalyst with sulfur doping in the second-shell of FeN4 (Fe-1-NSC) was verified by X-ray absorption spectroscopy and aberration-corrected scanning transmission electron microscopy. Fe-1-NSC exhibits superior CO2RR performance compared to sulfur-free FeN4 and most reported Fe-based SACs, with a maximum CO Faradaic efficiency of 98.6 % and turnover frequency of 1197 h(-1). Kinetic analysis and in situ characterizations confirm that sulfur doping accelerates H2O activation and feeds sufficient protons for promoting CO2 conversion to *COOH, which is also corroborated by the theoretical results. This work deepens the understanding of the CO2RR mechanism based on SAC catalysts.

• 单位
  郑州大学; 桂林理工大学