Sustainable production of methanol from one-pot catalytic conversion of cellulose over non-precious copper-based catalysts

Abstract

Methanol is an important bio-based platform molecule that can be used directly as a fuel or fuel additive, and can also be used to catalytically produce bulk chemicals and drop-in fuels. Currently, methanol is mainly produced from methane and coal via an indirect syngas route, which has the disadvantage of higher energy consumption. Here, we report a novel approach for the sustainable production of methanol from catalytic conversion of cellulose over a series of non-precious Cu-based catalysts, including Cu-TiO2-Al2O3 (Cu-TiAl), Cu-ZnO-Al2O3 (Cu-ZnAl), Cu-ZrO2-Al2O3 (Cu-ZrAl), and so on. The effects ofcatalyst supports, Culoading, and reaction conditions on the methanol yield from catalytic conversion of cellulose were systematically evaluated. It is demonstrated that 5%Cu-TiAl showed the highest methanol yield of 30.7 wt% during catalytic conversion of cellulose at 250 °C and 1Mpa H2 for 10 h. The catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunner − Emmett − Teller analysis (BET), high-resolution transmission electron microscope (HR-TEM), and temperature-programmed desorption of ammonia (TPD) to reveal the possible catalyst structure–reactivity relationship of these Cu-based catalysts. It is found that the unique xOTi–Cu–AlOx interfacial structure and high acidity of 5%Cu-TiAl are beneficial for the selective cleavage of the C–C and C–O bonds within cellulose to form methanol. This work provides a simple and efficient method to produce cellulosic methanol with relatively low energy consumption.