Enhanced CO2 electrochemical reduction on single-atom catalysts with optimized environmental, central and axial chemical ambient

Single-atom catalysts (SACs) have received significant research interests for electrocatalytic CO₂ reduction reaction (CO₂RR) to produce valuable chemicals. Designing optimal SACs for CO₂RR is a great challenge because of the strong scaling relationship among the many carbon-containing intermediates. In this study, we designed high-performance SACs, breaking the scaling relationship through changing environmental nonmetals, central atoms and axial nonmetals together via a series of density functional theory (DFT) calculations. After screening through configuration stabilities, CO and CO₂ adsorption energy, limiting potential of H₂, product adsorption energy, limiting potential of products, energy barrier of C-C coupling process and AIMD simulations, we finally observed ten optimal SACs (Ti-N4-B, Ti-N4-Si, Ti-CN3-Si, Ti-CN2O(1)-S, Sc-C2NO(1)-B, Sc-C2NO(1)-Si, Ti-BCN2(2)-N, Sc-CN2O(3)-Si, Ru-C2NO(3)-C and Ti-BONC-C) after considering 4311 possible configurations with high activity and selectivity for HCOOH, CH₄ and C₂H₆O formation. Among them, Ti-N4-B, Ru-C2NO(3)-C, and Sc-C2NO(1)-B have the lowest overpotentials for producing HCOOH, CH₄, and C₂H₆O with U_L of -0.2 V, -0.29 V, and -0.51 V, respectively. Subsequently, electronic analysis is implemented to provide a more comprehensive explanation at the electronic level for the enhanced CO₂RR performance of the discovered SACs. Our research demonstrates that the performance of SACs on CO₂RR can be significantly enhanced and altered by the combination of environmental nonmetals, central atoms, and axial nonmetals in a rational design. Importantly, it also establishes a design principle for the rapid screening of prospective catalysts for CO₂RR with high activity and selectivity.