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

Abstract Constructing multi‐atomic interfaces architectures is promising for electrocatalytic CO 2 conversion, yet their synthesis and stability under industrial current densities remain challenging. Herein, multi‐atomic Bi interfaces (Bi 0 /Bi δ+ −O moiety) were precisely engineered by embedding atomically dispersed Bi centers, encompassing Bi single atoms and Bi atomic clusters into the substrate of porous Bi 2 O 3‐x nanosheets. The composite showcases outstanding CO 2 conversion performance across a wide pH range, attaining remarkable Faradaic efficiency for formate (FE formate ) of 96.48% (at ultralow potential of −0.5 V versus RHE) and 92.26% in alkaline and neutral electrolytes, along with exceptional long‐term stability over 150 h. Depending on the designed CH 3 OH electrooxidation catalyst (CuO x /ZnCo(OH) x ) at the anode to couple with CO 2 conversion, symmetrical/asymmetrical electrolyzers were developed. The approach could obtain high‐added value products with FE formate >90% at both electrodes, achieving a 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 effects effectively enhance preferential binding of *H and *CO 2 to form *OCHO, while simultaneously suppressing the undesired recombination of hydrogen species into H 2 , rationalizing the high selectivity. Further intermediacy of concentrated formate precursors for subsequent C–N coupling toward urea synthesis, establishing a pathway for sustainable evolution.