Ultrasonic-assisted titanium silicalite molecular sieve modification method

Abstract

The invention discloses an ultrasonic-assisted titanium silicalite molecular sieve modification method, and relates to the technical field of molecular sieve modification, and the modification methodcomprises the following steps: S1, mixing a silicalite molecular sieve raw powder mother liquor, a template agent and mesoporous silica in proportion, and then carrying out primary heating for alcoholremoval; then adding tetra-n-butyl titanate, the template, mesoporous silica and tetra-n-butyl titanate in a molar ratio of (33-42): (5.5-14.8): 1; and S2, after heating and alcohol removal, carryingout secondary heating and alcohol removal on the mixed solution to prepare a titanium-silicon gelling reaction solution, heating and crystallizing the titanium-silicon gelling reaction solution at the temperature of 170-195 DEG C for 55-65 hours, carrying out solid-liquid separation on the obtained solid-liquid mixture to obtain a raw powder mother solution and a solid, and washing, drying and roasting the solid, carrying out superfine grinding treatment after roasting, and filtering with a 80-mesh sieve to obtain titanium silicalite molecular sieve raw powder. The method is beneficial to combination of the metal salt and the titanium silicalite molecular sieve, and the catalytic oxidation activity is further improved.

Description

technical field [0001] The invention relates to the technical field of molecular sieve modification, in particular to an ultrasonic-assisted modification method for titanium-silicon molecular sieves. Background technique [0002] Titanium silicate molecular sieve is made of Ti 4+ Part of Si instead of all-silicon molecular sieve 4+ A class of zeolite molecular sieves with MFI-type structure formed. Due to ion Ti 4+ It has the characteristics of six coordination and has the potential to accept electron pairs, so molecular sieves are suitable for H 2 o 2 Or organic peroxygen compounds have good adsorption and activation properties. [0003] Cyclohexanone oxime is considered as an important raw material for chemical production, and it is a key intermediate in the production of nylon-6 monomer ε-caprolactam. In the 1980s, Montedipe S.p.A, Italy successfully developed the ammoximation process of cyclohexanone, which uses cyclohexanone, ammonia and H 2 o 2 As a raw materia...

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Problems solved by technology

[0004] However, the existing titanium-silicon molecular sieves have large grain size and large pore volume, which is not conducive to actual catalysis. At the same time, metal compounds are not easy to graft in the pore volume of titanium-silicon molecular sieves.

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