Y/MCM-48 composite molecular screen and preparation method thereof

Abstract

The invention relates to a catalytic material of a composite molecular sieve containing micropore Y-zeolite phase and mediated hole MCM- 48 phase, which is produced by taking mixed cationic and non-ion surfactant as template; the invention also relates to a preparation method of the catalytic material. By adopting a method of overgrowth and employing mixed aqueous solution of cationic surfactant: cetylíítrimethyl ammonium bromide(CTAB) and nonionic surfactant: p -octyl polyethylene phenyl ether OP-10 as template, under the alkaline hydrothermal condition the invention synthesizes composite molecular sieve which is provided with Y / MCM-48 with micropore and two-mode mediated holes. The framework ratio Si / Al of microporous phase Y-zeolite of the composite molecular sieve is higher than traditional Y-zeolite, and the ratio Si / Al and the content of the framework of microporous phase can be adjusted by changing synthesis conditions. The method of the invention has simple operation and good repeatability, which provides with optional materials for developing novel catalyst with industrial application prospect, and the synthesis has practical application value.

Description

Technical field [0001] The invention relates to a kind of composite molecular sieve catalyst material prepared by using a mixed cationic-nonionic surfactant as a template and simultaneously containing a microporous Y zeolite phase and a mesoporous MCM-48 phase and a preparation method thereof. Background technique [0002] Since the advent of synthetic microporous molecular sieves in the 1960s, microporous molecular sieves have played a very important role in acid-catalyzed reactions due to their uniform pore structure and strong acidity, creating huge wealth for mankind. The mainstay of the development of petrochemical industry, but with the demand of heavy oil products and the reaction of medicine and biological macromolecules, the narrow pores of microporous molecular sieve limit its application. The emergence of mesoporous molecular sieve has brought dawn to the application of heavy oil and macromolecules, but its weak acidity and hydrothermal instability caused by the disord...

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Problems solved by technology

However, most of them are limited to the composite of MCM-41 with one-dimensional straight channels and micropores, and are synthesized with a single surfactant as a template, which only solves the problem of presence or absence, and does not realize the content of microporous phase in composite molecular sieves. Controllable Synthesis of Framework Si / Al

Another important member of the MCM41S series, the three-dimensional double-helical channel MCM-48, has better diffusion performance than the one-dimensional straight channel MCM-41, but it is difficult to synthesize because of its narrow formation phase region and harsh formation conditions. In addition, the synthesis conditions of Y and MCM-48 are quite different, and the concentration required for the synthesis of a single cationic surfactant is large and uneconomical, so there is no report on the Y / MCM-48 composite molecular sieve so far, and the current heavy oil cracking Catalysts usually use Y-type molecular sieve as the main active component. The content of Y component in the composite molecular sieve and the skeleton Si / Al ratio can be adjusted to meet the needs of different catalytic reactions. Therefore, the Y / MCM-48 composite molecular sieve can be synthesized under control. will have more practical significance

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