Regulating Pd-catalysis for electrocatalytic CO2 reduction to formate via intermetallic PdBi nanosheets

Electrocatalytic CO2 reduction plays an important role in the reduction of the CO2 concentration in atmosphere and consequently the mitigation of greenhouse effects. Pd has been extensively investigated as an electrocatalyst for the CO2 reduction to formate, which is an important raw material in the production of organic chemicals. However, the low selectivity and competitive reaction (hydrogen evolution reaction (HER)) have hindered the performance of monometallic Pd catalysts. In this paper, intermetallic PdBi nanosheets (NSs) are prepared for efficient CO2 reduction to formate. The highest Faradaic efficiency (FE) of formate on fully ordered PdBi NSs reaches 91.9% at −1.0 V vs. RHE, which outperforms that of the disordered PdBi and pure Pd catalysts. Density functional theory calculations suggest that compared to disordered PdBi NSs, the ordered structure can decrease the free energy barrier of *OCHO (a key intermediate of formate formation) and inhibit H2 evolution as well, thereby enhancing the activity and selectivity for formate production.