Bi-Eu bimetallic catalysts enabling ultrastable electroreduction of CO2 with a ∼ 100% formate Faradaic efficiency

Electrochemical reduction of CO 2 (ERCO 2 ) is an effective way to convert CO 2 into useful chemical products. However, most catalysts used for ERCO 2 show poor selectivity and stability. Here, we design a Bi 8 Eu 1 bimetallic catalyst, which exhibits both excellent stability (>400 h) and Faradaic efficiency for formate production (∼100% at − 0.89 V RHE ). Moreover, high Faradaic efficiency (>97%) is observed over a wide potential window (from − 0.89 V RHE to − 1.19 V RHE ). In a flow-cell, the Bi 8 Eu 1 catalyst shows an ultra-high current density of 250 mA cm −2 at − 0.77 V RHE . Density functional theory calculations indicate that the Bi-Eu interactions activate the Bi sites for strongly stabilizing *OCHO intermediates, thus promoting the conversion of CO 2 to formate. This work provides insights into the design of excellent electrocatalysts for ERCO 2 with improved activity and durability.