Theoretical Design of Cage-like Borophene Single Atom Catalyst for High Efficiency CO₂RR

Using renewable energy to reduce carbon dioxide (CO2) into a value-added chemical or fuel is regarded as an effective way to achieve energy conversion, chemical energy storage, and carbon neutrality. Borocagene is a cage-like borophene structure with large surface area, good chemical stability, and electrical conductivity. This research employs density functional theory (DFT) to construct metal atom-loaded borocagene (TM@Bcg) as a potential catalyst for the CO2 reduction reaction (CO2RR). The results indicate that TM@Bcg exhibit good stability and conductivity, and significantly inhibit the hydrogen evolution reaction (HER). Co@Bcg and Ni@Bcg are located at the top of the volcano where the CO and HCOOH product is generated with overpotential of 0.08 and 0.03 V, implying minimal additional voltage required to reduce CO2 to CO and HCOOH. Furthermore, Ni@Bcg shows superior catalytic activity for reducing CO2 to CH3OH and CH4, primarily due to its optimal adsorption strength for the crucial *CO intermediate, with Gibbs free energy of only 0.23 eV for the potential determining step (PDS). This study provides valuable guidance for the rational design of highly active and selective CO2RR catalysts.