(569bt) Computational Design of Graphene-Based Single-Atom Catalysts for Electrochemical Carbon Dioxide Upgrading

Perpetuating CO₂ emissions generated by traditional fossil fuels will offset progress made by renewables. CO₂ upgrading via electrochemical CO₂ reduction (CO₂R) could create a circular carbon economy that will simultaneously curtail rising concentrations in the atmosphere and reduce unsustainable petroleum consumption. However, none of the existing catalysts can achieve high production rates at relatively low applied potentials. Graphene-based single-atom catalysts (SACs) have emerged as promising catalysts for multiple reactions due to their highly tunable electronic structures and atom-efficiency, yet the relationship between composition, structure, and catalytic performance for electrochemical CO₂R remains unclear. In this work, we use multi-scale quantum mechanical simulations to understand the role of metal centers and dopants in tuning SAC activity. We then elucidate possible reaction mechanisms of CO₂R towards generating methane and methanol on selected SACs and identify several promising SACs with high activity and selectivity. Our work offers fundamental insights into improving catalytic performance of SACs by controlling their compositions and structures, as well as surface chemistry of CO₂R on SACs, which is different from our conventional understanding on metallic surfaces.