Rapid synthesis of amorphous bimetallic copper-bismuth electrocatalysts for efficient electrochemical CO2 reduction to formate in a wide potential window

The electrochemical reduction of CO2 to produce valuable chemicals is a promising strategy for alleviating the environmental problems and energy crisis, but its development is limited by the poor catalytic activity and selectivity of most electrocatalysts. In this study, an amorphous bimetallic copper-bismuth (Cu-Bi) electrocatalysts for the efficient electrochemical reduction of CO2 to formate has been developed for the first time. Among the prepared electrocatalysts, CuBi-100 shows the maximum Faradaic efficiency (FE) of 94.7 % ± 2.8 % at −1.0 V vs. RHE for the conversion to formate and also exhibits long-term stability. Notably, the CuBi-100 electrocatalyst also exhibits high selectivity (FE > 85 %) toward formate in a wide potential window (400 mV). The superior performance is mainly attributed to the numerous reaction sites originating due to the inherent irregular atomic structures on the amorphous bimetallic Cu-Bi electrocatalysts. These structures, help in accelerating the charge transfer and facilitate the formation and adsorption of CO2*− intermediates, thereby improving the formate selectivity in the CO2RR.