First Principles Investigations of Electrocatalyst Design for Mg-CO2 Batteries

Abstract

Carbon di-oxide (CO2) is the leading greenhouse gas responsible for global warming and catastrophic consequences on environmental imbalance. Metal-CO2 batteries have grabbed significant attention in the scientific community because of the unique feature of simultaneously consuming CO2 for the production of green electricity. In this regard, Mg- CO2 battery is especially highly promising because of its high volumetric capacity, low-cost, natural abundance. However, several roadblocks such as sluggish reaction kinetics of CO2 reduction, poor reversibility during charging and discharging cycles, and high charge overpotential needs to overcome the practical realization of Mg-CO2 batteries. The target performance of Mg-CO2 batteries can only be achieved through developing efficient cathode catalysts. In this study, we employ first-principles density functional theory (DFT) calculations to screen for electrocatalysts to achieve expedited reaction kinetics. Single-atom catalysts (SACs) are atomically dispersed metal atoms on a substrate and have evolved as an established strategy for ensuring the maximum utilization of catalytically active atoms in heterogeneous catalysis. The high throughput DFT simulations will be leveraged to understand the adsorption behavior of the reaction intermediates of Mg-CO2 batteries on the SACs. The derived free energy profile will illustrate the favorable reaction pathways to identify high performing SACs. The screening will be spanned over the first two rows of the transition metals.