Single-phase mixed molybdenum-niobium carbides: Synthesis, characterization and multifunctional catalytic behavior in toluene conversion

•Carbide precursors synthesized by hydrothermal and flash-freezing methods.•Single-phase molybdenum-niobium carbides with cubic or hexagonal structure produced.•Structure and bi-functionality (metallic, acidic) tunable by varying metal ratio.•Mo-rich carbides selective toward toluene hydrogenation and hydrogenolysis.•Nb-rich carbides catalyze hydrogenation, hydrogenolysis and ring contraction.