Impact of Subsurface Oxygen on CO2 Charging Energy Changes in Cu Surfaces

Abstract

Subsurface oxygen in oxide-derived copper catalysts significantly influences CO₂ activation. However, its effect on the molecular charging process, the key to forming the CO₂^δ− intermediate, remains poorly understood. We employ many-body perturbation theory to investigate the impact of the structural factors induced by the subsurface oxygen on the charged activation of CO₂. By computing the molecular single-particle state energy of the electron-accepting orbital on the Cu (111) surface, we examined how this molecular quasi-particle (QP) energy changes with the varying vicinity of adsorption and multiple-subsurface oxygen configuration. We demonstrate that subsurface oxygen impairs CO₂ charging, with its presence and coverage being influential factors. However, we remark that density functional theory calculations do not predict such an excitation energy discrepancy induced by subsurface oxygen. The nonlocal potential proves to be substantial for accurate excitation energy predictions yet is not sensitive to minor atomic structural changes. More importantly, state delocalization and hybridization are critical for determining QP energy. These insights are enlightening for designing atomic architectures to optimize catalytic performance on modified surfaces.