Core-shell type dehydration-hydrogenation bifunctional catalyst, preparation method and application of core-shell type dehydration-hydrogenation bifunctional catalyst in preparation of dihydric alcohol from xylose

Abstract

The invention discloses a core-shell type dehydration-hydrogenation bifunctional catalyst, a preparation method and application of the core-shell type dehydration-hydrogenation bifunctional catalyst in preparation of dihydric alcohol from xylose, the core of the prepared core-shell type dehydration-hydrogenation bifunctional catalyst is an S-1 molecular sieve for packaging metal, the shell layer is an S-1 molecular sieve for packaging solid acid, and the metal and the solid acid are active components. The catalyst is respectively used for catalytic hydrogenation reaction and dehydration reaction. According to the catalyst, a dehydration reaction and a hydrogenation reaction are connected in series through a core-shell structure, xylose is controlled to be converted according to a route of dehydration first and then hydrogenation, xylose is remarkably inhibited from being directly hydrogenated into xylitol, and the yield of dihydric alcohol is increased to 85.0%; the S-1 molecular sieve is used for coating, the active component is limited in the pore channel of the molecular sieve, the sintering of the active component is prevented, the catalyst has good stability, and the cyclic utilization can be realized through roasting and reduction.

Description

technical field [0001] The invention belongs to the technical field of catalyst preparation and application, and in particular relates to a core-shell type dehydration-hydrogenation dual-function catalyst, a preparation method and its application in preparing dihydric alcohol from xylose. Background technique [0002] Xylose can be obtained from cheap and renewable lignocellulosic biomass. Under acidic conditions, xylose can be dehydrated to obtain important platform compounds. These platform compounds can be hydrogenated under the action of suitable catalysts to produce high value-added products binary alcohol. Glycol compounds are very important polyester polymer monomers. Ethylene glycol, propylene glycol, pentylene glycol, etc. can all be used to react with diacids to prepare polyester materials with excellent properties. [0003] Xu Jie et al. disclosed (Chinese patent CN101186560A) a method for preparing ethylene glycol, propylene glycol and glycerol from corncobs thr...

AI Technical Summary

Problems solved by technology

These widely reported molecular sieve-encapsulated metal catalysts can solve the problems of agglomeration and loss of active components, but only cover metal or hydrogenation active centers, and cannot be used to catalyze xylose to prepare diols

Chinese patent CN111514888A discloses a core-shell dual active site catalyst, the core is a hydrogenation metal, and the shell molecular sieve provides acid sites, but the catalyst synthesized by this method has the defects of uncontrollable acid active site types and content , which is obviously not suitable for the one-pot xylose conversion process that requires strict control of acid species and acid-hydrogenation active site ratio

Images