Preparation and application methods of transition-metal-supported tungsten-base catalyst

Abstract

The invention relates to preparation and application methods of a transition-metal-supported tungsten-base catalyst. The method comprises the following steps: preparing a tungsten-base catalyst by low-temperature liquid-phase hydrothermal synthesis, and directly supporting one or more transition metals onto the support surface by sodium borohydride chemical reduction to obtain the supported tungsten-base catalyst; and uniformly mixing the tungsten-base catalyst with cellulose and water, and carrying out hydrogenation catalytic degradation in a closed high-pressure reaction kettle to prepare ethanediol. The cellulose can be catalytically converted into ethanediol in a high-efficiency high-selectivity high-yield way, and the ethanediol yield is up to 76.3%. The method has the advantages of simple technique, favorable reproducibility, mild reaction conditions, high cellulose conversion rate and high ethanediol yield; all the raw materials are inorganic compounds; and the reaction raw materials in the application direction are renewable resources. The ethanediol is an important chemical raw material.

Description

technical field [0001] The invention relates to the preparation of a transition metal-loaded tungsten-based catalyst and its application on cellulose, especially a novel tungsten-based supported catalyst composed of tungsten trioxide and iridium, rhodium, platinum, palladium, ruthenium and other supporting components Degrade cellulose and convert it to ethylene glycol with high selectivity. Background technique [0002] In today's society, human beings' demand for energy is increasing, but traditional non-renewable fossil fuels such as oil and coal are facing increasing shortages, and the consumption of fossil fuels has made ecological deterioration and environmental problems more severe. Therefore, it is necessary to look for efficient, non-polluting The renewable biomass resources are imminent. Cellulose is the renewable resource with the largest yield on the earth, and its sources are very abundant, such as straw in agricultural production, wood waste in forestry product...

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Problems solved by technology

[0003] The preparation of ethylene glycol by degrading cellulose is considered to be a promising topic, but due to the large number of intramolecular and intermolecular hydrogen bonds in cellulose, the structure of cellulose is very stable. The cellulose is acid hydrolyzed first, and then the glucose obtained is used for later conversion and utilization. This process is not only cumbersome, but also causes serious environmental pollution problems (US 4476331)

Chinese patent (CN 101648140 A) uses water as solvent, adopts W 2 C / Al 2 o 3 , W 2 C / AC, Ni-W 2 Catalysts such as C / AC degrade cellulose by catalytic hydrogenation at 120-300°C for 30 minutes, and realize efficient conversion of cellulose into ethylene glycol through a one-step reaction process, but the preparation process of the catalyst is complicated and not suitable for scale-up production

According to the literature review, there is no transition metal directly supported on tungsten trioxide nanosheets to catalyze the hydrogenation degradation of cellulose, so that the cellulose is completely converted, and high-yield ethylene glycol is prepared by this method.

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