High-Efficient Hydrogenolysis of Xylose to Polyols Over Ni-W/CeO2 Catalysts

Catalytic hydrogenolysis of xylose to ethylene glycol (EG) and 1,2-propanediol (1,2-PG) is an important way for the high-value valorization of biomass. Herein, Ni-W/CeO2 catalysts prepared by incipient-wetness impregnation method were used for the hydrogenolysis of xylose to EG and 1,2-PG. Several characterizations such as X-ray diffraction (XRD), Transmission electron microscopy (TEM) and X-ray photoelectronic spectroscopy (XPS) were used to analyze the physicochemical properties of the catalysts. The effects of different Ni/W ratios and reaction conditions on the hydrogenolysis performance of the catalyst were investigated. The doping of W promoted the selective cleavage of C-C and C-O bonds of xylose, thus improved the yield of EG 1,2-PG. The doping of W can form interactions with Ni and increase the oxygen vacancy concentration of CeO2, which have a significant impact on the catalyst activity. When the Ni: W ratio is around 1:1, the catalyst has the best activity, and the total yield of diols can reach about 43.2%.. When xylan was used as the substrate, the total yield of diols can reach to 58.7%. The possible reaction mechanism of xylose hydrogenolysis was also discussed. This work developed a new catalyst system for the directional conversion of xylose to EG and 1,2-PG, which provided a new idea for the design of catalyst to converting lignocellulose, especially carbohydrate into high-value chemicals. [GRAPHICS] .