High‐density single‐atom Ni doping into α ‐ MoC 1 − x triggers orbital rehybridization for enhanced catalytic hydrogenation

Abstract

Cubic α ‐phase molybdenum carbide ( α ‐MoC 1− x ) exhibits a noble‐metal‐like electronic structure arising from the hybridization of Mo d‐orbital and C p‐orbital, yet the intrinsic activity is constrained by suboptimal substrate binding. Herein, a Ni single‐atom‐doped α ‐MoC 1− x catalyst with a Ni loading up to 5 wt% is prepared via one‐step carburization, which exhibits remarkable catalytic performance for hydrogenation of carbonyls, nitroarenes, and N‐heterocycles. In situ experiments and theoretical calculations demonstrate Ni promotes the low‐temperature formation of α ‐MoC 1− x and achieves high‐density atomic dispersion within the carbide lattice. Mo–C sites serve as the real active centers for hydrogenation, and Ni single atoms can trigger d‐p orbital rehybridization in α ‐MoC 1− x and an upward shift of the d‐band center, leading to optimized adsorption, dissociation, and migration of H‐species. This work provides an efficient pathway to improve the intrinsic property of α ‐MoC 1− x at the atomic level, thereby enhancing catalytic performance for, but not limited to, hydrogenation reactions.