Recent advances of bismuth-based electrocatalysts for CO2 reduction: Strategies, mechanism and applications

Electrocatalytic CO2 reduction reaction (CO2RR), driven by clean electric energy such as solar and wind, can not only alleviate environmental greenhouse effect stemming from excessive CO2 emissions, but also realize the storage of renewable energy, for it guarantees the production of value-added chemicals and fuels. Among CO2RR products, formic acid shows great advantages in low energy consumption and high added-value, and thus producing formic acid is generally considered as a profitable line for CO2RR. Bismuth-based electrocatalysts exhibit high formic acid selectivity in CO2RR. Herein, we review the recent progress in bismuth-based electrocatalysts for CO2RR, including material synthesis, performance optimization/validation, and electrolyzers. The effects of morphologies, structure, and composition of bismuth-based electrocatalysts on CO2RR performance are highlighted. Simultaneously, in situ spectroscopic characterization and DFT calculations for reaction mechanism of CO2RR on Bi-based catalysts are emphasized. The applications and optimization of electrolyzers with high current density for CO2RR are summarized. Finally, conclusions and future directions in this field are prospected.