Strained Cu(111) surface can be catalytic efficient for C–C coupling in CO2 electrochemical reduction

It is well accepted that the Cu(100) surface is catalytic active for C–C coupling in CO2 reduction. However, the (100) surface is less active for the preceding CO* formation process and, most importantly, less stable than other surfaces. In this work, we investigate the relationship between catalytic effects and general factors such as coordination number and spacing (strain) of the Cu surface atoms. We find that the former affects the CO* formation only and the latter affects both the CO* formation and the subsequent C–C coupling. Among all the strained surfaces with larger atomic spacing, the more stable Cu(111) surface is extraordinary and outperforms Cu(100) and the high index surfaces for CO2 reduction to C2 on Cu.