Vanadium-doped molybdenum carbides as a promising catalyst for C–N/C–C coupling reactions

Abstract

Vanadium-doped molybdenum carbides (V-Mo₂C) encapsulated in nitrogen-doped carbon have been prepared by annealing phosphovanadomolybdate (PMo₁₀V₂O₄₀⁵⁻)-paired ionic hybrids as the carbonization precursors. The V-Mo₂C@NC_t catalysts were pyrolyzed at various temperatures and characterized by XRD, BET, XPS, TEM, and Raman spectroscopy. The synthesized MoCV@NC₈₀₀ showed a pomegranate-like structure with V-Mo₂C nanocrystals well-dispersed in the NC shell. More importantly, MoCV@NC₈₀₀ revealed extremely good catalytic activity and stability in the oxidative C–N coupling of amines to imines under mild conditions, which was much better than those of the monometallic carbide control catalysts. It was also observed that MoCV@NC₈₀₀ exhibited high catalytic activity for the C–C bond couplings of alcohols and ketones. This work might provide a significant and interesting approach for designing more transition metal carbides as efficient organic synthesis heterogeneous catalysts.