Stable core-shell Janus BiAg bimetallic catalyst for CO2 electrolysis into formate

• Published in: Chinese chemical letters Vol. 36; no. 3; p. 110300
• Main Authors: Lou, Yaoyin, Huang, Xiaoyang Jerry, Zhao, Kuang-Min, Douthwaite, Mark J., Fan, Tingting, Lu, Fa, Akdim, Ouardia, Tian, Na, Sun, Shigang, Hutchings, Graham J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2025
• Subjects: BiAg; Cascade catalysis; CO2 reduction; Formate; Janus; Formate; BiAg; CO2 reduction; Janus; Cascade catalysis
• ISSN: 1001-8417
• DOI: 10.1016/j.cclet.2024.110300

CO2 electrolysis into formate is a promising technology with the potential to simultaneously alleviate energy shortages and global warming. However, the limited stability of the catalysts during long-term electrolysis hinders their widespread implementation. Herein, we show that a core-shell bimetallic BiAg catalyst with a multifaceted Janus structure at its core can achieve a stability of up to 300 h with a formate faradaic efficiency (FEformate) over 90% at −0.75 V vs. RHE (reversible hydrogen electrode) in an H-type cell. Our investigations reveal the important role of the Janus structure on the transfer of electrons, favoring their delocalization across the catalyst and enhancing their mobility. We propose that the compressive strain inclined to grain boundaries within this structure would lower the energy barrier for electrons transfer and promotes the cooperation between Ag and Bi. Indeed, Ag initiates the activation of CO2 through a series of cascade reactions and is subsequently hydrogenated on Bi. Additionally, our study suggests that Ag plays a crucial role in stabilizing the catalyst structure after long-term electrolysis. This work highlights a new strategy for tandem CO2 electrolysis, providing novel insights for the design of formate formation catalysts. Core-shell BiAg alloy enhances carbon dioxide electroreduction into fromate, through a cascade reaction mechanism, while simultaneously inhibiting the electrocorrosion of Bi during the process. This synergistic effect results in sustained formate generation with high selectivity across a broad potential range. [Display omitted]