Direct Catalytic Conversion Of Glucose Into Low Carbon Glycols Over Transition Metal Carbide Catalysts

With the development of chemical industry, it has been received more attention to produce chemical raw materials from renewable biomass resources. In this paper, carbon nanofibers supported carbide and precious metal catalysts were prepared and then evaluated in the glucose hydrogenolysis system to prepare ethylene glycol and 1,2-propylene glycol. The results indicated carbide catalysts had better catalytic performance than precious metal Pt. Moreover, tungsten carbide catalyst was better than molybdenum carbide. The differences in glucose conversion and yields to glycols among nickel and cobalt promoted carbide catalysts were also investigated. It was shown that the existence of nickel promoted the catalytic performance more than cobalt. The promotion of nickel on catalyst preparation and evaluation were studied in detail. The highest glucose conversion 93%, ethylene glycol yield 38% and 1,2-propylene glycol 15% were obtained over the optimized Ni-W2C catalyst. Meanwhile, the effect of different carbon supports on glucose hydrogenolysis process was studied. The results showed that the pore structures of supports had a obvious influence on product distribution. The larger the pore size was, the higher the relative selectivities of macromolecule 1,2-propylene glycol, glycerol and sorbitol were. When the micropores were dominant in the catalysts, the content of micromolecule product ethylene glycol was higher. For carbon nanofibers/graphite supported Ni-W2C catalyst, the product distribution after glucose hydrogenolysis reaction could be regulated by controlling the growth content of CNFs.