Two-dimensional MBene: a comparable catalyst to MXene for effective CO 2 RR towards C 1 products.

Electrochemical CO 2 reduction reaction (CO 2 RR) 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 CO 2 RR performance owing to their unique electronic properties. Herein, a novel 2D transition metal boride, MoB, is theoretically evaluated as a potential catalyst for the CO 2 RR by comparing it with traditional Mo 2 C. MoB shows metallic nature and exhibits excellent electrical conductivity. MoB can effectively activate CO 2 with a larger interaction energy of -3.64 eV than that of Mo 2 C. Both density of states and charge difference density reveal a significant charge transfer from MoB to CO 2 . MoB shows higher catalytic selectivity due to its inhibited hydrogen evolution reaction and low reaction energy for the CO 2 RR. At potentials more negative than -0.62 V, the CO 2 RR on MoB becomes a high-throughput reaction process towards CH 4 . This work discovered that MoB exhibited comparable CO 2 RR performance to Mo 2 C and forecasted MBenes as promising catalysts for electrocatalysis.