Two-dimensional MBene: a comparable catalyst to MXene for effective CORR towards C products.

Electrochemical CO reduction reaction (CORR) to high-value-added products is one of the most promising strategies for mitigating the greenhouse effect and energy shortage. Two-dimensional (2D) MXene materials are regarded as promising catalysts for electrocatalysis, and the boron-analogs of MXenes, 2D transition metal borides (MBenes), may exhibit superior CORR performance owing to their unique electronic properties. Herein, a novel 2D transition metal boride, MoB, is theoretically evaluated as a potential catalyst for the CORR by comparing it with traditional MoC. MoB shows metallic nature and exhibits excellent electrical conductivity. MoB can effectively activate CO with a larger interaction energy of -3.64 eV than that of MoC. Both density of states and charge difference density reveal a significant charge transfer from MoB to CO. MoB shows higher catalytic selectivity due to its inhibited hydrogen evolution reaction and low reaction energy for the CORR. At potentials more negative than -0.62 V, the CORR on MoB becomes a high-throughput reaction process towards CH. This work discovered that MoB exhibited comparable CORR performance to MoC and forecasted MBenes as promising catalysts for electrocatalysis.