Preparation method of alkene epoxidation catalyst as well as catalyst prepared thereby

Abstract

The invention relates to a preparation method of an alkene epoxidation catalyst. The preparation method of the alkene epoxidation catalyst comprises the following steps: (1) preparing titanium silicongel; (2) performing pore-enlarging treatment on the titanium silicon gel by using organic amine or liquid ammonia, drying and roasting to obtain titanium silicon composite oxide; (3) optionally performing alcohol solution treatment on organic alkali metal salt; and (4) optionally performing gas phase silanization treatment. The pore diameter of the catalyst prepared by the method is adjustable, so that the catalyst has higher activity on epoxidation reaction of olefin molecules with different kinetic diameter; and the catalyst is subjected to two-step modification, the surface acidity of thecatalyst is effectively reduced and the catalyst has higher epoxidation product selectivity.

Description

technical field [0001] The invention relates to a preparation method of an olefin epoxidation catalyst, in particular to a preparation method of a titanium-silicon composite oxide catalyst. The invention also relates to the olefin epoxidation catalyst prepared by the preparation method and its application in olefin epoxidation. Background technique [0002] For chemicals such as epoxy resins, surfactants, coatings, adhesives, and surface coating reagents that are widely used in life and industry, epoxy compounds are a class of general-purpose intermediate raw materials for the synthesis of these chemicals and have great potential. demand. The traditional production process of synthesizing epoxy compounds is generally chlorohydrin method or co-oxidation method, but this kind of method has the disadvantages of heavy pollution, large corrosion of equipment, many by-products, and high cost. [0003] Therefore, many companies at home and abroad are devoting themselves to the de...

AI Technical Summary

Problems solved by technology

Both the vapor deposition method and the sol-gel method have the following disadvantages: the preparation process is cumbersome, the operation is complicated, the conditions are harsh and difficult to control, and the reaction time is long.

In addition, once the conditions are not properly controlled, the resulting catalyst is likely to generate more extra-skeletal titanium compounds (mainly free titanium dioxide), the surface of the catalyst is more acidic, and the effective utilization rate of organic peroxides is lower when used in the epoxidation of propylene.

[0008] In summary, the current conventional microporous titanium-silicon molecular sieves are too small for C 6 The above macromolecular olefin epoxidation reaction activity is very low, which limits its application in olefin epoxidation; Mesoporous molecular sieve materials such as Ti-MCM-41 and Ti-SBA-15 can be used for macromolecular olefins and EBHP Or the epoxidation reaction of CHP as the oxidant, but these catalysts have the characteristics of difficult synthesis, difficult preparation and high price of the template used, resulting in high cost and limited industrial application; SiO 2 Titanium-silicon catalyst prepared by vapor deposition method or liquid phase impregnation method as a carrier, due to the presence of acidic free TiO on the surface 2 , and the loading of titanium active centers is low, resulting in low catalyst selectivity and reactivity

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