Promising Ru-based cathode catalysts for Li-CO₂ batteries via single-atom alloying

Lithium-carbon dioxide (Li-CO₂) batteries have garnered increased attention due to their high energy density and the utilization of the greenhouse gas CO₂. However, the weak CO₂ activation and low cathode activity hinder the development of current Li-CO₂ batteries. Ru-based catalysts have become the preferred choice of catalysts in Li-CO₂ batteries; in this study, 10 single atom alloy catalysts (SAAs) composed of ruthenium (Ru) doped with 3d transition metal atoms (MRu) as cathode materials for Li-CO₂ batteries were investigated by first principles calculations. The thermodynamic stability and CO₂ activation capability of pure Ru and 10 SAAs were determined by calculating the formation energy of MRu and the adsorption energy of CO₂ on the catalysts. The selectivity of reaction pathways and catalytic activity of the catalysts were evaluated by thermodynamic reaction energy and kinetic reaction energy barriers. Among 10 MRu SAAs, ScRu and TiRu were screened as superior catalysts compared to the Ru metal. This work offered a rational theory design for promising Ru-based catalysts.