Operando Converting BiOCl into Bi2O2(CO3)xCly for Efficient Electrocatalytic Reduction of Carbon Dioxide to Formate

Huai Qin Fu; Junxian Liu; Nicholas M Bedford; Yun Wang; Joshua Wright; Peng Fei Liu; Chun Fang Wen; Liang Wang; Huajie Yin; Dongchen Qi; Porun Liu; Hua Gui Yang; Huijun Zhao

doi:10.1007/s40820-022-00862-0

Operando Converting BiOCl into Bi₂O₂(CO₃)_xCl_y for Efficient Electrocatalytic Reduction of Carbon Dioxide to Formate

Nanomicro Lett. 2022 May 3;14(1):121. doi: 10.1007/s40820-022-00862-0.

Authors

Huai Qin Fu¹, Junxian Liu¹, Nicholas M Bedford², Yun Wang¹, Joshua Wright³, Peng Fei Liu⁴, Chun Fang Wen⁴, Liang Wang¹, Huajie Yin¹, Dongchen Qi⁵, Porun Liu⁶, Hua Gui Yang⁴, Huijun Zhao⁷

Affiliations

¹ Centre for Catalysis and Clean Energy, Gold Coast Campus, Griffith University, Gold Coast, QLD, 4222, Australia.
² School of Chemical Engineering, University of New South Wales, Sydney, NSW, 2052, Australia.
³ Department of Physics, Illinois Institute of Technology, Chicago, IL, 60616, USA.
⁴ Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai, 200237, People's Republic of China.
⁵ Centre for Materials Science, School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD, 4001, Australia.
⁶ Centre for Catalysis and Clean Energy, Gold Coast Campus, Griffith University, Gold Coast, QLD, 4222, Australia. p.liu@griffith.edu.au.
⁷ Centre for Catalysis and Clean Energy, Gold Coast Campus, Griffith University, Gold Coast, QLD, 4222, Australia. h.zhao@griffith.edu.au.

Abstract

Bismuth-based materials (e.g., metallic, oxides and subcarbonate) are emerged as promising electrocatalysts for converting CO₂ to formate. However, Bi^o-based electrocatalysts possess high overpotentials, while bismuth oxides and subcarbonate encounter stability issues. This work is designated to exemplify that the operando synthesis can be an effective means to enhance the stability of electrocatalysts under operando CO₂RR conditions. A synthetic approach is developed to electrochemically convert BiOCl into Cl-containing subcarbonate (Bi₂O₂(CO₃)_xCl_y) under operando CO₂RR conditions. The systematic operando spectroscopic studies depict that BiOCl is converted to Bi₂O₂(CO₃)_xCl_y via a cathodic potential-promoted anion-exchange process. The operando synthesized Bi₂O₂(CO₃)_xCl_y can tolerate - 1.0 V versus RHE, while for the wet-chemistry synthesized pure Bi₂O₂CO₃, the formation of metallic Bi^o occurs at - 0.6 V versus RHE. At - 0.8 V versus RHE, Bi₂O₂(CO₃)_xCl_y can readily attain a FE_HCOO- of 97.9%, much higher than that of the pure Bi₂O₂CO₃ (81.3%). DFT calculations indicate that differing from the pure Bi₂O₂CO₃-catalyzed CO₂RR, where formate is formed via a ^*OCHO intermediate step that requires a high energy input energy of 2.69 eV to proceed, the formation of HCOO^- over Bi₂O₂(CO₃)_xCl_y has proceeded via a ^*COOH intermediate step that only requires low energy input of 2.56 eV.

Keywords: Carbon dioxide reduction; Cathodic potential-promoted anion-exchange; Chloride-containing bismuth subcarbonate; Stability.