Dual-metal-boron system: A promising candidate electrocatalyst towards CO2 reduction reaction

Abstract

Metal borides have found extensive use in breaking the inert chemical bonds in small molecules due to their outstanding catalytic capabilities. Meanwhile, the dual-metal catalysts (DACs) have garnered much attention owing to their numerous active sites and adjustable chemical properties. Inspired by these findings, 55 different dual-metal-boron based systems were constructed by introducing two transition metal atoms (TMs) into boron-doped graphene (BG). Their catalytic performance towards CO₂ reduction reaction (CO₂RR) was studied by employing density functional theory calculations. It is found that the MnZn@BG electrocatalyst could effectively reduce the CO₂ into CH₄ with a low limiting potential of -0.29 V. The catalytic performance of MnZn@BG is enhanced under acidic conditions. Furthermore, the competitive hydrogen evolution reaction is effectively suppressed on MnZn@BG, contributing to its high selectivity for CO₂RR. Machine learning analysis revealed that, except for the widely used d-band center descriptor, the number of d-electrons on TMs significantly influences the CO₂ adsorption strength on TM1TM2@BG. These results suggest that the MnZn@BG is a promising candidate as a CO₂RR electrocatalyst, offering insights into the application of dual-metal-boron systems in sustainable energy conversion.