Controllable Cu0‐Cu+ Sites for Electrocatalytic Reduction of Carbon Dioxide

Abstract Cu‐based electrocatalysts facilitate CO 2 electrochemical reduction (CO 2 ER) to produce multi‐carbon products. However, the roles of Cu 0 and Cu + and the mechanistic understanding remain elusive. This paper describes the controllable construction of Cu 0 ‐Cu + sites derived from the well‐dispersed cupric oxide particles supported on copper phyllosilicate lamella to enhance CO 2 ER performance. 20 % Cu/CuSiO 3 shows the superior CO 2 ER performance with 51.8 % C 2 H 4 Faraday efficiency at −1.1 V vs reversible hydrogen electrode during the 6 hour test. In situ attenuated total reflection infrared spectra and density functional theory (DFT) calculations were employed to elucidate the reaction mechanism. The enhancement in CO 2 ER activity is mainly attributed to the synergism of Cu 0 ‐Cu + pairs: Cu 0 activates CO 2 and facilitates the following electron transfers; Cu + strengthens *CO adsorption to further boost C−C coupling. We provide a strategy to rationally design Cu‐based catalysts with viable valence states to boost CO 2 ER.