Chemoselective hydrodeoxygenation of palmitic acid to diesel-like hydrocarbons over Ni/MoO2@Mo2CTx catalyst with extraordinary synergic effect

Abstract

Chemoselective hydrodeoxygenation (HDO) of lipids to diesel-like hydrocarbons is important for biomass to biofuel conversion. Here we design a new Ni-based catalyst (Ni/MoO2@Mo2CTx) with extraordinary catalytic performance in the HDO of palmitic acid. To relieve the loss of C atom for Ni-based catalyst, partial oxidation of Mo2CTx MXene was used as a novel support. As a result, the catalytic activity and selectivity ratio of hexadecane/pentadecane (C16/C15) were enhanced over Ni/MoO2@Mo2CTx catalyst, and the major product of palmitic acid HDO is C16, demonstrating a high C atom economy. This facilitated catalytic performance may be ascribed to the synergic effect of metal Ni, Mo2CTx MXene as well as MoO2 active sites. The palmitic acid (–COOH) can convert into hexadecanal (–CHO) and hexadecanol (–CH2OH) over Ni/MoO2@Mo2CTx catalyst in the initial stage. The metal Ni further contributes to the hydrogenation of the hexadecanal to C15 with the cleavage of C–C bonds by decarbonylation (DCO) route. MoO2 nanoparticles obtained from Mo2CTx oxidation accelerate the scission of C–O bonds of the hexadecanol to improve the selectivity of C16 by hydrogenation-dehydration route.