Catalyst, preparation method and application of acetophenone hydrogenation to prepare α-phenylethanol

Abstract

The invention discloses a preparation method of a catalyst for preparing α-phenethyl alcohol by liquid-phase hydrogenation of acetophenone. sol, and stir evenly to prepare a silica sol water dispersion; configure a mixed salt solution containing copper, zinc, rare earth metal, alkaline earth metal compound salts and an alkaline precipitant, and add the two together to the silica sol water dispersion. In the process, the catalyst is obtained through precipitation reaction, aging, filtration, washing, drying, roasting and molding; the invention also discloses the prepared catalyst and its application. The invention adopts silica sol and silicate as composite silicon source, adds organic pore-forming agent before the precipitation process, and uses Zn, rare earth and alkaline earth metal to modify the catalyst, and is used for the liquid phase hydrogenation of acetophenone to prepare α-benzene When ethanol is used, it not only has high activity and good selectivity, but also effectively improves the liquid resistance of the catalyst, with high strength and good stability.

Description

technical field [0001] The invention belongs to the technical field of catalytic hydrogenation, and in particular relates to a catalyst for preparing α-phenethyl alcohol by liquid-phase hydrogenation of acetophenone, a preparation method and application thereof. Background technique [0002] α-Phenylethyl alcohol is an important chemical intermediate widely used in medicine, fragrance manufacturing, cosmetics, food and fine chemical industries. The existing α-phenylethanol synthesis methods mainly include microbial fermentation and acetophenone reduction / catalytic hydrogenation. [0003] Microbial fermentation generally uses phenylalanine and fluorophenylalanine as raw materials to produce α-phenylethanol through microbial fermentation. The raw materials used in the microbial method are expensive and the production cost is high. At present, the industrial production of α-phenylethanol usually adopts the hydrogenation method of acetophenone. This method has the advantages o...

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Problems solved by technology

CN1557545A prepared Ni-Sn-B / SiO by dipping method 2 Catalyst, after low-temperature roasting, KBH4 is used as a reducing agent for reduction. During the catalytic reaction, the highest selectivity of phenylethyl alcohol is 97.5%, but the interaction between the active component Ni and the carrier SiO2 is weak and easy to be lost

[0006] US4996374 discloses a kind of Pd-C catalyst, but its catalyst stability is relatively poor, needs to constantly improve reaction temperature when applying mechanically

CN1315226A discloses a reduction-treated copper-based catalyst and a method for preparing α-phenylethanol, but it needs to adopt a liquid-phase reduction method to improve the stability of the catalyst, and the process is complicated and the cost is high

CN1911883A discloses a method for preparing α-phenylethanol with Raney nickel as a catalyst, but there are more aromatic ring hydrogenation products α-cyclohexyl alcohol in its acetophenone hydrogenation product, and α-phenylethanol selectivity lower

[0010] In the prior art, copper-based catalysts used in liquid-phase hydrogenation reactions are not only affected by various internal or external forces in the process of storage / filling / reduction / reaction, but also due to liquid immersion, swelling, etc. The strength is greatly reduced, causing the catalyst to be easily broken and pulverized in the liquid phase hydrogenation system, threatening the stable operation of industrial equipment and affecting the life of the catalyst

[0011] At present, the hydrogenation of acetophenone prepared by the precipitation method to prepare α-phenylethyl alcohol copper catalysts usually has problems such as low dispersion of active component copper, strong catalyst acidity, weak interaction between the carrier and the active component, etc., resulting in acetophenone Low conversion rate, large amount of by-products such as ethylbenzene, poor selectivity of phenylethanol, poor catalyst strength

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