High-selectivity CO2-to-CH4 electrochemical reduction on copper trimer: A theoretical insight

The pursuit of enhanced catalysts represents a pivotal yet challenging undertaking in the realm of CO2 reduction to CH4 powered by renewable electricity. The development of high-performance catalysts has been constrained by the scaling between *CO and *CHO, coupled with inadequate selectivity. Here, we report a design strategy that addresses the limitation by formulating Cu trimer-anchored MXene-based catalysts using density functional theory studies. This advancement was achieved by enhancing the selectivity of *OCHO via constructing oxyphilic sites, introducing a hydrogen bond promoter for *HCOOH deep reduction, and a multi-site synergy strategy for stabilizing complex intermediates (e.g., *H2COOH), and therefore reshaping the linear relationship between adsorbates. Consequently, a novel volcano model was constructed using the adsorption free energy of *OCHO as an activity descriptor. Based on the microkinetic analysis, it is predicted that a high current density could potentially be achieved on Cu3@V2NO2 at an applied potential of -1.10 V vs. reversible hydrogen electrode. This study proposes new catalyst design approaches for CO2 conversion, accompanied by a thorough exploration of the thermodynamic and kinetic aspects of the reduction process.