Understanding the Electrochemical Carbon Dioxide Reduction Reaction Mechanism of Lattice Tuning of Copper by Silver Single-Crystal Surface.

Intermolecular interactions and adsorbate coverage on a metal electrode's surface/interface play an important role in CO reduction reaction (CORR). Herein, the activity and selectivity of CORR on bimetallic electrode, where a full monoatomic Cu layer covers on Ag surface (Cu/Ag) are investigated by using density functional theory calculations. The surface geometric and electronic structure results indicate that there is high electrocatalytic activity for CORR on the Cu/Ag electrode. Specifically, the Cu/Ag surface can accelerate the HO and CO adsorption and hydrogenation while lowering the reaction energy of the rate-determining step. The structure parameters of chemisorbed CO with and without HO demonstrate that activated HO not only promotes the C-O dissociation but also provides the protons required for CORR on the Cu/Ag electrode surface. Furthermore, the various reaction mechanism diagrams indicate that the Cu/Ag electrode has high selectivity for CORR, and the efficiency of products can be regulated by modulating the reaction's electric potential.