Modulating CO 2 Electroreduction on Dual-Atom Catalysts through Orbital Interactions

The electrochemical CO2 reduction reaction (CO2RR) efficiency and selectivity are limited by the high stability of the CO2 molecules and the complexity of the reaction pathways. We herein investigated the geometric configuration, orbital interaction, and spin states of Fe/Co dual-atom catalysts (DACs) that regulate the CO2RR mechanism by using density functional theory calculations. It is demonstrated that the spatial structure and orientation of frontier orbitals of DACs determine both the CO2 physisorption/chemisorption behavior and the following reaction pathway as well as product selectivity. Notably, the spin engineering effectively manipulates d-orbital energy splitting, thereby altering the rate-limiting step and reducing the limiting potential of CO2RR. Furthermore, the manipulation of the spin state of metals in DACs results in a clear volcano-type relationship between dual-metal dyz+z2+xz orbitally resolved energy level and the rate-limiting potential in CO2RR. This work provides an atomic-scale theoretical framework for the rational design of efficient dual-atom catalysts for CO2RR.