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

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

doi:10.1002/anie.202206233

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

Angew Chem Int Ed Engl. 2022 Aug 8;61(32):e202206233. doi: 10.1002/anie.202206233. Epub 2022 Jun 28.

Authors

Shanyong Chen^{1

2}, Xiaoqing Li¹, Cheng-Wei Kao³, Tao Luo¹, Kejun Chen¹, Junwei Fu¹, Chao Ma⁴, Hongmei Li^{1

5}, Ming Li⁶, Ting-Shan Chan³, Min Liu¹

Affiliations

¹ Hunan Joint International Research Center for Carbon Dioxide Resource Utilization, State Key Laboratory of Powder Metallurgy, School of Physical and Electronics, Central South University, Changsha, 410083, China.
² Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 511443, China.
³ National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan.
⁴ School of Materials Science and Engineering, Hunan University, Changsha, 410082, China.
⁵ School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, 450001, China.
⁶ College of Science & Ministry-province jointly-constructed Cultivation Base for State Key Laboratory of Processing for Mom-ferrous Metal and Featured Materials & Key Lab. of Nonferrous Materials and New Processing Technology, Guilin University of Technology, Guilin, 541004, China.

PMID: 35674117
DOI: 10.1002/anie.202206233

Abstract

Heteroatom-doping in metal-nitrogen-carbon single-atom catalysts (SACs) is considered a powerful strategy to promote the electrocatalytic CO₂ reduction reaction (CO₂ RR), but the origin of enhanced catalytic activity is still elusive. Here, we disclose that sulfur doping induces an obvious proton-feeding effect for CO₂ RR. The model SAC catalyst with sulfur doping in the second-shell of FeN₄ (Fe₁ -NSC) was verified by X-ray absorption spectroscopy and aberration-corrected scanning transmission electron microscopy. Fe₁ -NSC exhibits superior CO₂ RR 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 H₂ O 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 CO₂ RR mechanism based on SAC catalysts.

Keywords: CO2 Electroreduction; Heteroatom Doping; Proton-Feeding Effect; Reaction Kinetics; Single-Atom Catalysts.

Abstract

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