Insight into the Behavior of Interstitial Electrons in CuZn Alloy‐Functionalized Covalent Organic Framework Catalysts for Enhanced CO ₂ Electroreduction

Abstract

Abstract The development of application‐oriented, highly active, and selective CO 2 reduction reaction (CO 2 RR) electrocatalysts for high value‐added products is expected to achieve carbon neutrality and solve the problem of energy shortage. Cu‐based catalysts, as the most promising catalysts for high value‐added product generation, were often limited by slow CO generation and weak CO adsorption in practical applications. Guided by theoretical screening, herein, an atomic‐scale CuZn alloy cluster configuration was manipulated on covalent organic frameworks (COFs), and its CO 2 RR performance was further improved by the regulation of the electron‐donor functional groups. Through systematic characterization and theoretical simulations, we for the first time demonstrate and quantify the interstitial electrons in CuZn alloy clusters under the regulation of electron‐giving groups. Further in situ surface‐enhanced Raman spectroscopy (SERS) and simulation results reveal that the behavior of interstitial electrons with low work function and high mobility occupy the high‐energy orbital of the metal and easily transfer to *CO, therefore, the *CO is hydrogenated to *COH before coupling, and then the coupling energy barrier and path are optimized. Due to these attributes, the as‐developed CuZn alloy‐functionalized COF catalyst (CuZn–COF–OH) exhibits significantly improved activity and selectivity, with >200 mA cm −2 industrial‐grade current density and ethylene Faraday efficiency of up to ∼79% at −1.0 V versus RHE. This study provides innovative avenues and insights for the design and development of application‐oriented atomic‐scale catalysts.