Si Doping-Induced Electronic Structure Regulation of Single-Atom Fe Sites for Boosted CO2 Electroreduction at Low Overpotentials

Changsheng Cao; Shenghua Zhou; Shouwei Zuo; Huabin Zhang; Bo Chen; Junheng Huang; Xin-Tao Wu; Qiang Xu; Qi-Long Zhu

doi:10.34133/research.0079

Si Doping-Induced Electronic Structure Regulation of Single-Atom Fe Sites for Boosted CO₂ Electroreduction at Low Overpotentials

Research (Wash D C). 2023:6:0079. doi: 10.34133/research.0079. Epub 2023 Mar 15.

Authors

Changsheng Cao¹, Shenghua Zhou^{1

2}, Shouwei Zuo³, Huabin Zhang³, Bo Chen⁴, Junheng Huang⁵, Xin-Tao Wu^{1

2

6}, Qiang Xu^{7

8}, Qi-Long Zhu^{1

2

6}

Affiliations

¹ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, China.
² University of Chinese Academy of Science, Beijing, 100049, China.
³ KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
⁴ Department of Chemistry, City University of Hong Kong, Hong Kong, 999077, China.
⁵ CAS Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Provincial Key Laboratory of Nanomaterials, FujianInstitute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, 350002, China.
⁶ Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, 350108, China.
⁷ Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto 606-8501, Japan.
⁸ Shenzhen Key Laboratory of Micro/Nano-Porous Functional Materials (SKLPM), SUSTech-Kyoto University Advanced Energy Materials Joint Innovation Laboratory (SKAEM-JIL), and Department of Materials Science and Engineering, Southern University of Science and Technology (SUSTech), Shenzhen, 518055, China.

Abstract

Transition metal-based single-atom catalysts (TM-SACs) are promising alternatives to Au- and Ag-based electrocatalysts for CO production through CO₂ reduction reaction. However, developing TM-SACs with high activity and selectivity at low overpotentials is challenging. Herein, a novel Fe-based SAC with Si doping (Fe-N-C-Si) was prepared, which shows a record-high electrocatalytic performance toward the CO₂-to-CO conversion with exceptional current density (>350.0 mA cm^-2) and ~100% Faradaic efficiency (FE) at the overpotential of <400 mV, far superior to the reported Fe-based SACs. Further assembling Fe-N-C-Si as the cathode in a rechargeable Zn-CO₂ battery delivers an outstanding performance with a maximal power density of 2.44 mW cm^-2 at an output voltage of 0.30 V, as well as high cycling stability and FE (>90%) for CO production. Experimental combined with theoretical analysis unraveled that the nearby Si dopants in the form of Si-C/N bonds modulate the electronic structure of the atomic Fe sites in Fe-N-C-Si to markedly accelerate the key pathway involving *CO intermediate desorption, inhibiting the poisoning of the Fe sites under high CO coverage and thus boosting the CO₂RR performance. This work provides an efficient strategy to tune the adsorption/desorption behaviors of intermediates on single-atom sites to improve their electrocatalytic performance.