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

Abstract

A series of indium oxide-modified Cu/SiO2 catalysts were synthesized and used to produce ethanol via methyl acetate hydrogenation. In-Cu/SiO2 catalyst containing 1.0 wt% In2O3 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/SiO2 increased the copper dispersion, diminished the copper crystallite size, and enriched the surface Cu+ concentration. Furthermore, the Cu/SiO2 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.