Hydrodeoxygenation of benzyl alcohol on transition-metal-containing mixed oxides catalysts derived from layered double hydroxide precursors

M-MgAlO mixed oxide catalysts were prepared by controlled thermal decomposition of layered double hydroxides (LDH) precursors and were tested in the hydrodeoxygenation of benzyl alcohol. LDH with Mg/Al= 3 and 10 at. % M with respect to cations (M = Mn, Fe, Co, Ni, Cu and Zn) were obtained by coprecipitation. A second series of copper-containing catalysts with copper content from 5 to 20 at. % was also prepared. The solids were characterized by X-ray diffraction, N-2 adsorption/desorption, temperature-programmed reduction in H-2 atmosphere, temperature-programmed desorption of CO2. The influence of the transition metal and, for the copper-containing samples, of the copper loading, reaction temperature, reaction time, amount of catalyst and reduction pre-treatment on the catalytic performance were investigated. With 97% alcohol conversion and 96% selectivity to toluene, Cu15MgAlO is the best hydrodeoxygenation catalyst. It was also tested in the hydrodeoxygenation of 1-heptanol.