The role of MnOx in Cu-MnOx/SiO2 catalysts for the gas-phase hydrogenation of furfural

Abstract

A series of Cu-MnOx/SiO2 catalysts was synthesized using different methodologies: incipient wetness impregnation and strong electrostatic adsorption for the incorporation of Cu species, and incipient wetness impregnation and controlled surface reactions for the addition of MnOx. The materials were characterized by H2-TPR, XRD, XPS, TEM/EDX, and N2 adsorption-desorption at -196 °C to study the interaction between Cu and MnOx species. These catalysts were evaluated in the gas-phase hydrogenation of furfural at 190 °C. While a highly dispersed Cu/SiO2 catalyst promoted the hydrogenolysis of furfuryl alcohol to methylfuran, it was found that the presence of oxygen vacancies in MnOx facilitated the interaction of the catalysts with the carbonyl group of furfural, thus promoting the formation of furfuryl alcohol as the main product.