Efficient catalytic transfer hydrogenation of furfural to furfuryl alcohol in near-critical isopropanol over Cu/MgO-Al2O3 catalyst

Abstract

Catalytic transfer hydrogenation of furfural to furfuryl alcohol is considered to be a very important industrial process. In this work, non-noble Cu supported on MgO-Al2O3 catalysts have been prepared by co-precipitation and have shown excellent catalytic performance for conversion of furfural to furfuryl alcohol in near-critical iso-propanol. The effects of the Cu state (reduction degree and dispersion) and loading in Cu/MgO-Al2O3, acidity of catalysts have been investigated by X-ray diffraction (XRD), coupled plasma optical emission spectrometry (ICP-OES), N2 adsorption and desorption (N2-BET) and temperature-programmed desorption of ammonia (NH3-TPD), which have led to high activity for producing furfuryl alcohol. The results have shown that the selectivity of furfuryl alcohol has been influenced by the Cu state, Lewis acidity, reaction temperature and reaction time. The mechanisms, Lewis acid- and metal mediated hydrogenation, have shown that a desirable balance of Cu loading and Lewis acidity of catalyst has influenced the activity significantly. Almost 100% furfural conversion, with 89.3% furfuryl alcohol yield has been obtained. Cycling tests have shown that the prepared catalysts have been stable, where recycling the catalysts at least four times has not shown any reduction in activity.