Self-propagating high-temperature synthesis of composite materials containing tungsten carbides: The effect of phase composition on the yield of ethylene glycol and propylene glycol in the single-step hydrolysis-hydrogenolysis of cellulose

Abstract

It was shown that the hydrolysis-hydrogenolysis of cellulose to alcohols can be catalyzed by a two-component system Ca(OH) 2 – composite material containing tungsten carbides (W 2 C/WC), which are obtained by a combination of mechanochemical activation and self-propagating high-temperature synthesis (SHS) using an exothermic mixture of tungsten oxide, metallic magnesium and carbon black. The introduction of inert additives (metallic tungsten or calcium carbonate) in the exothermic mixture allowed controlling the amount and ratio of tungsten carbides (W 2 C, WC). The introduction order of reagents in the exothermic mixture and their activation affected the textural properties of materials. Advantages of the SHS method over mechanical activation were demonstrated. The catalytic properties of these materials were studied in the hydrolysis- hydrogenolysis of cellulose. Phase composition of the composite materials was found to affect the yield of ethylene glycol (EG) and 1,2-propylene glycol (1,2-PG) and their ratio. The maximum total yield of EG and 1,2-PG (25–31 %) was obtained in the presence of a sample with high W 2 C content.