Main‐Group Metal Single‐Atomic Regulators in Dual‐Metal Catalysts for Enhanced Electrochemical CO2 Reduction

Abstract Single‐atom sites can not only act as active centers, but also serve as promising catalyst regulators and/or promoters. However, in many complex reaction systems such as electrochemical CO 2 reduction reaction (CO 2 RR), the introduction of single‐atom regulators may inevitably induce the competitive hydrogen evolution reaction (HER) and thus reduce the selectivity. Here, the authors demonstrate that introducing HER‐inert main‐group metal single atoms adjacent to transition‐metal single atoms can modify their electronic structure to enhance the CO 2 RR to CO without inducing the HER side reaction. Dual‐metal Cu and In single‐site atoms anchored on mesoporous nitrogen‐doped carbon (denoted as Cu‐In‐NC) are prepared by the pyrolysis of a multimetallic metal–organic framework. Cu‐In‐NC shows a high faradic efficiency of 96% toward CO formation at −0.7 V versus reversible hydrogen electrode, superior to that of its monometallic single‐atom counterparts. Density functional theory studies reveal that the HER‐inert In sites can activate the adjacent Cu sites through electronic modifications, strengthening the binding of *COOH intermediate and thus boosting the electrochemical reduction of CO 2 to CO.