Dynamic reconstructuring of CuS/SnO2-S for promoting CO2 electroreduction to formate

• Published in: Journal of energy chemistry 2023-07, Vol.82, p.497-506
• Main Authors: Dou, Tong, He, Jinqing, Diao, Shuteng, Wang, Yiping, Zhao, Xuhui, Zhang, Fazhi, Lei, Xiaodong
• Format: Article
• Language: English
• Subjects: CO2 reduction; CuSn alloy; Electrocatalysis; Structural reconstruction
• ISSN: 2095-4956
• DOI: 10.1016/j.jechem.2023.03.016

CuS/SnO2-S nanoparticles were transformed to Cu/Sn/Cu6.26Sn5 nanowires via structural reconstruction during the initial CO2 electroreduction and showed a CO2-to-formate conversion with a Faradaic efficiency of 84.9% at −0.8 V vs. RHE. [Display omitted] As the “emission peak and carbon neutrality peak” are proceeding all over the world, CO2 electroreduction is studied extensively as it is a powerful way to transform CO2 into value-added products. The earth-abundant Sn-based materials and copper sulfides as electrochemical catalysts have shown activity for generating formate from CO2 electroreduction. Herein, the composite of CuS and S-doped SnO2 (CuS/SnO2-S) was synthesized by a redox reaction under room temperature. The unique structural reconstruction of CuS/SnO2-S nanoparticles to Cu/Sn/Cu6.26Sn5 nanowires decreases the energy barrier of the adsorption of CO2, and increases the adsorption of *H, primarily suppressing the competing reaction of hydrogen evolution reaction (HER). As a result, at − 0.8 V vs. RHE, it reaches an electrochemical CO2-to-formate conversion with a Faradaic efficiency (FE) of 84.9% at a yield of 8860 µmol h−1 cm−2 under a partial current density of ∼18.8 mA cm−2 in an H-type reactor. This study provides significant insight into the structural evolution of the CuSn sulfides and the mechanism of formate formation.