Dimethyl benzyl alcohol hydrogenolysis catalyst and preparation method thereof

Abstract

The invention discloses a dimethyl benzyl alcohol hydrogenolysis catalyst and a preparation method thereof. The catalyst comprises 35-70wt% of copper oxide, 5-25wt% of zinc oxide, 15-40wt% of silicondioxide, 0.5-15wt% of alkaline earth metal oxide and 0.1-5wt% of bismuth oxide and lead oxide. The preparation method comprises the following steps: (a) adding a mixed solution containing a Cu compound, a Zn compound, an alkaline earth metal compound, a Bi compound and a Pb compound and an alkaline precipitant solution into a silica sol aqueous solution for precipitation reaction and heating aging; (b) filtering, washing, drying and roasting the aged slurry to obtain complex compound powder; and (c) adding a binder, a forming assistant and the like into the complex compound powder, fully mixing, extruding and forming, drying and roasting to obtain the catalyst. When used for preparing cumene by hydrogenolysis of dimethylbenzyl alcohol, the method not only has good activity and selectivity,but also has good liquid resistance and high mechanical stability.

Description

technical field [0001] The invention belongs to the technical field of catalysis, and in particular relates to a dimethyl benzyl alcohol hydrogenolysis catalyst and a preparation method thereof. Background technique [0002] Propylene oxide (PO) is an important organic chemical raw material, mainly used in the production of polyether polyol (polyurethane raw material), propylene glycol, etc. developer etc. [0003] Industrial PO production methods mainly include chlorohydrin method, hydrogen peroxide direct oxidation method and co-oxidation method (Halcon method). The chlorohydrin method is the main route for producing PO in China. This process has serious problems such as equipment corrosion and environmental pollution. Due to the high raw material cost of the direct hydrogen peroxide oxidation route, the economy is affected. [0004] The co-oxidation method, also known as co-production method or indirect oxidation method, is to generate propylene oxide through the react...

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Problems solved by technology

[0007] The hydrogenolysis catalysts of dimethyl benzyl alcohol mainly include platinum-palladium precious metal catalysts, nickel-based catalysts and copper-based catalysts, etc., the cost of noble metal catalysts and nickel-based catalysts is high, and it is easy to cause Saturated aromatic ring, poor selectivity to cumene

[0018]The active center of the copper-based catalyst is the reduced metal copper grains. Because the melting point of metal copper is relatively low, the growth of copper grains and the Sintering will directly lead to a reduction in the number of active sites of the catalyst and a decrease in catalyst activity

The decrease in hydrogenolysis activity will induce side reactions such as polymerization, which will cause the active site of the catalyst to be covered by the polymer and the carrier pores to be blocked by the polymer, resulting in a decrease in the activity and stability of the catalyst.

[0019] In the prior art, copper-based catalysts used for hydrogenolysis reactions are not only affected by various internal or external forces in the process of storage, loading, reduction, and reaction, but also Due to liquid immersion, swelling and other reasons, the actual use strength of the catalyst will be greatly reduced, resulting in the catalyst being easily broken and pulverized in the liquid phase system, affecting the life of the catalyst and threatening the stable operation of industrial devices

[0020] At present, the Cu-based catalyst prepared by the prior art is used for the catalytic hydrogenolysis of dimethyl benzyl alcohol to prepare cumene, and there is a low dispersion of active component copper, The strong acidity of the catalyst and the weak interaction between the carrier and the active component lead to problems such as low catalyst activity, poor high temperature stability, poor liquid resistance, and serious environmental pollution.

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