Influence of Brønsted acid sites on the product distribution in the hydrodeoxygenation of methyl laurate over supported Ru catalysts

The production of biofuels (hydrocarbons) from renewable biomass resources has attracted much attention in the fields of green energy and sustainable chemistry. Herein, catalytic hydrodeoxygenation of methyl laurate ( n -C 11 H 23 COOCH 3 ) to produce hydrocarbons n -C 12 H 26 and n -C 11 H 24 has been investigated over Ru dispersed on acidic supports H-ZSM-5, Al 2 O 3 and SiO 2 , and the reaction rate and the product distribution were discussed and correlated with surface Brønsted and Lewis acid sites and active Ru species in detail. The reaction rate at the initial stage increased with the amount of the total acid sites, and the ratio of n -C 12 H 26 / n -C 11 H 24 and the selectivity to n -C 12 H 26 were positively correlated with the amount of Brønsted acid sites. The Ru active species presented to be more electron-deficient on the catalysts with a larger amount of Brønsted acid sites on which an η 1 -(O) adsorption configuration of 1-C 11 H 23 CHO was confirmed, which favoured the formation of n -C 12 H 26 , thus varying the product distribution. Besides, Brønsted acid sites could provide protons to promote the hydrogenolysis of n -C 11 H 23 COOCH 3 and the following dehydration to produce n -C 12 H 26 .