Engineering the structural formula of N-doped molybdenum carbide nanowires for the deoxygenation of palmitic acid

Abstract

Molybdenum carbides are known to be promising substitutes for noble metals used in the upgradation of bio-oil. The catalytic properties depend on the structure and heteroatom modification significantly. Herein, N-doped molybdenum carbide (Mo_xCN_y) nanowires were synthesized at a very low temperature (≤500 °C) by the one-step pyrolysis of an Mo-based organic–inorganic hybrid (Mo-3atrz) for the first time. The relationship between the structural formula and performance of the as-prepared Mo_xCN_y nanowires in the deoxygenation of palmitic acid was explored. The conversion of palmitic acid over the Mo_xCN_y nanowires proceeds mainly via the hydrodeoxygenation route: palmitic acid → hexadecanal → hexadecanol → hexadecene → hexadecane. Adjusting “x” and “y” in the Mo_xCN_y nanowires efficiently changes their intrinsic electron distribution and leads to electron transfer within Mo, C and N, thus resulting in alterable Mo_xCN_y properties. The connection between the regioselective cleavage of the C–O bonds and the structural formula of Mo_xCN_y is verified. Mo_2.56CN_0.50 with an optimized formula exhibits excellent activity (99.6% conversion of palmitic acid) and 99.2% selectivity to alkanes.