Selective hydrodeoxygenation of fatty acid esters on PdZn/Mo-Al2O3: The influences of Mo and Zn on adsorption and selectivity.

The conversion of fatty acid esters to alkanes with high carbon chain number by hydrodeoxygenation (HDO) is of great significance in biomass conversion to fuels and chemicals. A PdZn/Mo-Al2O3-C catalyst was prepared for the preparation of octadecane from methyl stearate HDO. The coexistence of Pd and Zn on Mo-based catalysts greatly promoted the dispersion of active sites on the catalyst surface, which also effectively regulated the distribution of acid sites on the catalyst surface. The Zn modified Pd catalyst also effectively adsorbed the CO/C-O bond of the substrate to facilitate the cleavage of C-O bonds, as well as suppressing the decarboxylation side reaction, and achieving octadecane selectivity of 92%. The optimized catalyst also displayed high HDO selectivity for converting the fatty acid esters (C8 ∼ C18) to alkanes.