Method for rapidly synthesizing mesoporous Silicalite-1 molecular sieve by taking silica gel as silicon source

Abstract

The invention relates to the field of preparation of a zeolite molecular sieve Silicalite-1 and particularly relates to a method for rapidly synthesizing mesoporous Silicalite-1 molecular sieve by taking silica gel as a silicon source. The method comprises the steps of with a small amount of tetrapropylammonium bromide as a microhole template agent, a cheap KF as a mesoporous template agent, silicon sol as the silicon source as well as deionized water as a solvent, adding a trace amount of seed crystals, heating in a reaction kettle, carrying out crystallization to obtain a crystallization solution, and carrying out centrifugation, washing, drying and calcination, so as to obtain the Silicalite-1 molecular sieve. The preparation method has the beneficial effects that the selected raw materials are economic, the reaction time is short, and data is full and accurate.

Description

technical field [0001] The invention relates to the field of preparation of zeolite molecular sieve Silicalite-1, in particular to a method for rapidly synthesizing mesoporous Silicalite-1 molecular sieve using silica sol as a silicon source. Background technique [0002] Among the many researched zeolite molecular sieve materials, materials with mesoporous pores have attracted the attention of experts in many fields because of their characteristics of improving mass transfer and increasing active sites. Silicalite-1 is the pure silicon form of ZSM-5 molecular sieve, which has a very high ratio of silicon to aluminum and micropores of 0.46-0.54nm. Mesoporous Silicalite-1 molecular sieve has hydrophobicity and two pore sizes of micropore and mesopore, and has application potential in specific catalytic field. [0003] In 2008, Xie Zaiku et al. reported that nano-CaCO 3 As a mesoporous template, TPAOH (tetrapropylammonium hydroxide) synthesized mesoporous Silicalite-1 as a m...

AI Technical Summary

Problems solved by technology

In 2014, AnilKumarSinha and others synthesized mesoporous Silicalite-1 by using organosilane as mesoporous template and TPAOH as microporous template, in which TPAOH / SiO 2 =0.5, the amount of microporous template agent is relatively large, the price of mesoporous template agent organosilane is expensive, and the reaction time is as long as 5 days

Although no mesoporous template was used and the synthesis time was short, the synthesis was continuously stirred at 70°C until it became a gel, and the degree of water evaporation was difficult to grasp, and the reaction at 130°C in the later stage required strict sealing, making the synthesis difficult , it is difficult to achieve large-scale synthesis

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