Hydrodeoxygenation of biomass-derived fatty acids and esters to biofuels on RuRe/ZSM-5 catalysts: Synergistic effects of ReOx and Brønsted acid sites

The hydrodeoxygenation of fatty acids and esters is a critical pathway to produce biofuels. We report an efficient RuRe/ZSM-5(18) catalyst for hydrodeoxygenation of methyl laurate, the selectivity of n -C 12 H 26 reached up to 95.2 % at complete conversion under the reaction conditions of 200 °C, 3 MPa H 2 , 3 h. The contribution of ReO x and acid sites was discussed from the perspective of dynamics and thermodynamics. ReO x was available for the adsorption of substrate and intermediates, the acidity from ReO x species and ZSM-5 are conducive to the cleavage of C O bond. The synergistic effects of ReO x and Brønsted acid sites induced Ru 0 species to be electron-deficient, which preferred to adsorb aldehyde group in a linear adsorption configuration and facilitated for the hydrogenation of the aldehyde intermediate to alcohol, followed by dehydration to produce hydrocarbons. Thus, RuRe/ZSM-5(18) catalyst presented superior activity and chemoselectivity in the hydrodeoxygenation of methyl laurate as well as a series of fatty acids and esters without loss in carbon numbers in reactant.