A highly selective and durable electrocatalyst for carbon dioxide (CO2) conversion to formate is developed, consisting of tin (Sn) nanosheets decorated with bismuth (Bi) nanoparticles. Owing to the formation of active sites through favorable orbital interactions at the Sn‐Bi interface, the Bi‐Sn bimetallic catalyst converts CO2 to formate with a remarkably high Faradaic efficiency (96%) and production rate (0.74 mmol h−1 cm−2) at −1.1 V versus reversible hydrogen electrode. Additionally, the catalyst maintains its initial efficiency over an unprecedented 100 h of operation. Density functional theory reveals that the addition of Bi nanoparticles upshifts the electron states of Sn away from the Fermi level, allowing the HCOO* intermediate to favorably adsorb onto the Bi‐Sn interface compared to a pure Sn surface. This effectively facilitates the flow of electrons to promote selective and durable conversion of CO2 to formate. This study provides sub‐atomic level insights and a general methodology for bimetallic catalyst developments and surface engineering for highly selective CO2 electroreduction.

Transition metal atoms with corresponding nitrogen coordination are widely proposed as catalytic centers for the oxygen reduction reaction (ORR) in metal–nitrogen–carbon (M–N–C) catalysts. Here, an effective strategy that can tailor Fe–N–C catalysts to simultaneously enrich the number of active sites while boosting their intrinsic activity and utilization is reported. This is achieved by edge engineering of FeN4 sites via a simple ammonium chloride salt‐assisted approach, where a high fraction of FeN4 sites are preferentially generated and hosted in a graphene‐like porous scaffold. Theoretical calculations reveal that the FeN4 moieties with adjacent pore defects are likely to be more active than the nondefective configuration. Coupled with the facilitated accessibility of active sites, this prepared catalyst, when applied in a practical H2–air proton exchange membrane fuel cell, delivers a remarkable peak power density of 0.43 W cm−2, ranking it as one of the most active M–N–C catalysts reported to date. This work provides a new avenue for boosting ORR activity by edge manipulation of FeN4 sites.

Electrochemical CO 2 reduction (CO 2 RR) using renewable energy sources represents a sustainable means of producing carbon-neutral fuels. Unfortunately, low energy efficiency, poor product selectivity, and rapid deactivation are among the most intractable challenges of CO 2 RR electrocatalysts. Here, we strategically propose a "two ships in a bottle" design for ternary Zn−Ag−O catalysts, where ZnO and Ag phases are twinned to constitute an individual ultrafine nanoparticle impregnated inside nanopores of an ultrahigh-surface-area carbon matrix. Bimetallic electron configurations are modulated by constructing a Zn−Ag−O interface, where the electron density reconfiguration arising from electron delocalization enhances the stabilization of the *COOH intermediate favorable for CO production, while promoting CO selectivity and suppressing HCOOH generation by altering the rate-limiting step toward a high thermodynamic barrier for forming HCOO*. Moreover, the pore-constriction mechanism restricts the bimetallic particles to nanosized dimensions with abundant Zn−Ag−O heterointerfaces and exposed active sites, meanwhile prohibiting detachment and agglomeration of nanoparticles during CO 2 RR for enhanced stability. The designed catalysts realize 60.9% energy efficiency and 94.1 ± 4.0% Faradaic efficiency toward CO, together with a remarkable stability over 6 days. Beyond providing a high-performance CO 2 RR electrocatalyst, this work presents a promising catalyst-design strategy for efficient energy conversion.

CO2 electroreduction reaction offers an attractive approach to global carbon neutrality. Industrial CO2 electrolysis towards formate requires stepped-up current densities, which is limited by the difficulty of precisely reconciling the competing intermediates (COOH* and HCOO*). Herein, nano-crumples induced Sn-Bi bimetallic interface-rich materials are in situ designed by tailored electrodeposition under CO2 electrolysis conditions, significantly expediting formate production. Compared with Sn-Bi bulk alloy and pure Sn, this Sn-Bi interface pattern delivers optimum upshift of Sn p-band center, accordingly the moderate valence electron depletion, which leads to weakened Sn-C hybridization of competing COOH* and suitable Sn-O hybridization of HCOO*. Superior partial current density up to 140 mA/cm2 for formate is achieved. High Faradaic efficiency (>90%) is maintained at a wide potential window with a durability of 160 h. In this work, we elevate the interface design of highly active and stable materials for efficient CO2 electroreduction.