Atomically Dispersed Pd Promotes Water Activation and Electrochemical CO 2 Reduction to Formate on Bismuth Catalysts
Wenjing Tian, Fei Fan, Hui‐Zi Huang, Min Zhang, An‐Xiang YinABSTRACT
Electrocatalytic CO 2 reduction reaction (CO 2 RR) offers a sustainable route for converting CO 2 into value‐added chemicals, but its efficiency is limited by sluggish kinetics and poor selectivity. Herein, we report the controlled synthesis of atomically dispersed Pd‐modified Bi nanosheets (Pd 2.5% –Bi NSs) via a solvent‐guided solvothermal method followed by in situ electroreduction. Solvent engineering regulates the morphology of Bi 2 O 3 precursors, resulting in Bi NSs with a high electrochemically active surface area. The incorporation of Pd optimizes the electronic structure, enhances the adsorption of the *OCHO intermediate, and lowers the energy barrier for CO 2 RR. Notably, atomically dispersed Pd sites facilitate H 2 O dissociation to provide sufficient active hydrogen, thereby accelerating the protonation kinetics in CO 2 RR. As a result, Pd 2.5% –Bi NSs deliver a current density of 287 mA cm −2 at −1.0 V versus the reversible hydrogen electrode, while maintaining a high formate Faradaic efficiency (FE formate , >91.0%) over a wide current density range of 50–300 mA cm −2 , with a maximum FE formate of 95.7% at 200 mA cm −2 in an alkaline flow cell. These results highlight the synergistic effects of moderate morphological control and atomic‐level Pd incorporation, providing insights for the rational design of efficient CO 2 RR catalysts toward selective formate production.