Selective Sieving Effect of Multi‐Atomic Bismuth Interfaces for Efficient Formate Electrosynthesis and Evolution at Industrial Current Density

Abstract

Constructing multi‐atomic interfaces architectures are promising for electrocatalytic CO2 conversion, yet their synthesis and stability under industrial current densities remain challenging. Herein, multi‐atomic Bi interfaces (Bi0/Biδ+ moiety) were precisely engineered by embedding atomically dispersed Bi centers, encompassing both Bi single atoms and Bi atomic clusters into the substrate of porous Bi2O3‐x nanosheets. The composite showcases outstanding CO2 conversion performance, attaining remarkable faradaic efficiency for formate (FEformate) of 96.48% (at ultralow potential of ‐0.5 V vs. RHE) and 92.26% in alkaline and neutral electrolytes, along with exceptional long‐term stability over 150 h. Depending on designed CH3OH electrooxidation catalyst (CuOx/ZnCo(OH)x) at the anode, which couples CO2 conversion at the cathode, symmetrical/asymmetrical electrolyzer system were developed. The approach could obtain high‐added value products with FEformate >90% at both electrodes, achieving production rate of 4980 µmol h−1 cm‐2 under industrial current density. Combined In situ characterizations and theoretical calculations unravel that multiple atomic interfaces featuring interfacial atomic sieving effect effectively enhance preferential binding of *H and *CO2 to form *OCHO, while simultaneously suppressing the undesired recombination of hydrogen species into H2, rationalizing the high selectivity. Further intermediacy of concentrated formate precursors for subsequent C−N coupling toward urea synthesis, establishing pathway for sustainable evolution.