Multi-doped borophene catalysts with engineered defects for CO₂ reduction: A DFT study

Carbon dioxide reduction reaction (CO₂RR) to convert carbon dioxide (CO₂) into value-added products via the electrochemical method is a conducive way to tackle the hazard of high CO₂ emissions. The present DFT study reports a novel dual chromium-anchored tri-vacancy borophene (Cr₂/TV-β₁₂) electrocatalyst, which showed high selectivity and stability for CO₂RR. A tri-vacancy defect was introduced in β₁₂ borophene to create an 11-membered ring borophene sheet (TV-β₁₂), and 28 different electrocatalysts were explored via doping various transition metals (Co, Cr, Cu, Fe, Mn, Ni, Zn). Density functional theory simulation results revealed that the Cr₂/TV-β₁₂ electrocatalyst adsorbs and activates CO₂ efficiently, which was validated by the partial density of states, charge density difference, Bader charge, and crystal orbital Hamilton population analyses. The limiting potential for CO₂RR was evaluated to be -0.45 V, against hydrogen evolution reaction (HER) (0.57 V), with the main product being formaldehyde. The catalyst showed selectivity towards CO₂ reduction and suppressed HER. The usual problem of carbon monoxide poisoning encountered in CO₂ reduction was also assessed and a high resistance against the same was established. At the outset, the research revealed that dual atom-doped tri-vacancy β₁₂ borophene has tremendous potential to be utilized as an efficient catalyst for CO₂RR.