Strain-mediated control of H availability on Cu(1 0 0): A DFT-driven strategy for selective CO2 electroreduction to C1/C2 products

Electrochemical reduction of carbon dioxide on copper-based catalysts leads to a wide distribution of C1/C2 products via various hydrogenation steps. It is highly required to seek for feasible strategies towards targeting products through mechanistic insights of some of the key reaction steps. In this study, we theoretically rationalized that crucial intermediates towards desirable C1/C2 on Cu(1 0 0) surface are achievable by directing hydrogen source available locally at the catalytic interface. The relative concentration of *CO and *H was shown to determine the thermodynamic stability of intermediates which led to diverse energetic landscapes. Further by introducing planar lattice tension within Cu(1 0 0), a controllable H availability was realized and the formation affinity of *CHO, *OCCHO/*OCCOH was enhanced while competitive hydrogen evolution reaction (HER) was suppressed. Moreover, interactions between the local reactive environment and Cu(1 0 0) were important in modulating surface H availability characterized by the thermodynamics of subsurface H insertion and kinetic infusion/effusion of H. Overall, our work highlights the need for a deeper understanding of interactions between intermediates and the catalysts which can play pivotal roles in tuning CO2RR selectivity and activity.