Hierarchical pore nanometer flower-like structure Ag catalyst of methyl glycolate prepared through oxalic ester hydrogenation

Abstract

The invention relates to a hierarchical pore nanometer flower-like structure Ag catalyst of methyl glycolate prepared through oxalic ester hydrogenation. Titanium-doped hierarchical pore nanometer flower-like silica balls are taken as a carrier, and silver is taken as an active ingredient; the weight percentage of the components in the catalyst is as follows: the weight percentage of the active ingredient such as silver is equal to 5 wt% to 20 wt%, the weight percentage of an additive such as TiO2 is equal to 0.5 wt% to 2.5 wt%, and the balance is silicon oxide; the preparation method comprises the following steps: adding a mixed liquor containing a silicon oxide precursor into a template mixed liquor, adding a titanium precursor after uniform stirring, carrying out hydrothermal crystallization, taking a product to carry out centrifugal separation and washing, vacuum drying and calcinations to obtain a hierarchical pore nanometer flower-like titanium silicon compound carrier; and adding a soluble silver precursor solution into the carrier, stirring, aging, and finally carrying out calcinations and reduction on an obtained drying product. The catalyst is of a hierarchical pore nanometer flower-like structure, so that the accessibility of active metal silver can be improved; and besides, the carrier is regulated and controlled by adopting titanium, and the dispersity of silver is improved through mutual effect of silver and titanium, so that the hydrogenation reaction activity of oxalic ester and the selectivity of methyl glycolate are strengthened.

Description

technical field [0001] The invention relates to an Ag catalyst with a hierarchical porous nanoflower structure for preparing methyl glycolate by hydrogenating oxalate. Background technique [0002] Methyl glycolate is a high value-added organic chemical intermediate, and is an excellent solvent for many cellulose, resins, and rubbers. It is widely used in industries such as chemical industry, medicine, pesticide, feed, spices and dyes. The downstream product branch of the center has broad application prospects. [0003] The methods of synthesizing methyl glycolate mainly include formaldehyde carbonylation esterification method of petroleum route, one-step oxidative esterification method and methyl formate and formaldehyde coupling method, and oxalate gas phase hydrogenation method of coal-to-synthesis gas route . The formaldehyde carbonylation esterification method requires substances such as strong acid or strong alkali, which is severely corrosive to the equipment, and t...

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Problems solved by technology

[0006] CN104923219A has reported a catalyst for the hydrogenation of oxalate to methyl glycolate, using silver as the main active component, palladium, platinum, ruthenium, barium, zinc, copper, calcium, magnesium, nickel, cobalt, manganese, cerium, iron , lanthanum or molybdenum as the catalytic component, silicon oxide, aluminum oxide, zirconium oxide, titanium oxide or silicon aluminum molecular sieve as the carrier, which better solves the problems of poor catalyst activity and low selectivity of methyl glycolate

[0009] Judging from the technology reported so far, methyl glycolate can be synthesized with high selectivity by using silver-based catalysts to catalyze the hydrogenation of oxalate, but due to the full d electron structure of silver, the adsorption capacity of hydrogen is weak, so silver The hydrogenation activity of the base catalyst is not high, and the selectivity of methyl glycolate obtained on the catalyst is not high, which affects the economics of this route. Therefore, how to achieve high conversion and high selectivity for the synthesis of glycolic acid Methyl ester is still a difficult research point for this technology

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