In2O3-modified Cu/SiO2 as an active and stable catalyst for the hydrogenation of methyl acetate to ethanol

A series of indium oxide-modified Cu/SiO 2 catalysts were synthesized and used to produce ethanol via methyl acetate hydrogenation. In-Cu/SiO 2 catalyst containing 1.0 wt% In 2 O 3 exhibited the best catalytic activity and stability. The physicochemical properties of the synthesized catalysts were investigated using several characterization methods and the results showed that introducing suitable indium to Cu/SiO 2 increased the copper dispersion, diminished the copper crystallite size, and enriched the surface Cu + concentration. Furthermore, the Cu/SiO 2 catalyst gradually deactivated during the stability test, which was mainly attributed to copper sintering and the valence change in surface copper species. In contrast, indium addition can inhibit the thermal transmigration and accumulation of copper nanoparticles to stabilize the catalyst.