Electrocatalytic CO2 Reduction Mechanisms on Two-Dimensional TM2B3 (TM = V, Cr, Fe, Co) Catalysts: A Density Functional Theory Investigation

The electrocatalytic CO₂ reduction reaction (CO₂RR) can create value-added chemicals and offer a dual solution for addressing climate change and energy crises. MBenes, a class of two-dimensional transition metal borides, exhibit promising potential in catalysis due to their unique electronic properties and uniformly exposed metal sites. Here, we theoretically evaluated the CO₂RR performance of a class of MBene, TM₂B₃ (TM = V, Cr, Fe, Co), monolayers. These materials effectively activated CO₂ due to the significant charge transfer from TM₂B₃ to *CO₂. Among them, Cr₂B₃ exhibits superior catalytic selectivity due to its ability to suppress the competing hydrogen evolution reaction (HER) and its low limiting potential (U_L = −0.31 V) in the process of the conversion of CO₂ to CH₄. Furthermore, the Gibbs free energies of various CO₂RR intermediates show a strong correlation with the *CO adsorption energy, highlighting its pivotal role as a descriptor for predicting the CO₂RR activity in these catalysts.