Synthesis method of defective zeolite molecular sieve rich in hydroxyl nests

Abstract

The invention provides a synthesis method of a defective zeolite molecular sieve rich in hydroxyl nests. The synthesis method comprises the following steps: mixing an inorganic silicon source and an organic silicon source which serve as a mixed silicon source with an aluminum source and an OSDA template agent to obtain sol, and crystallizing; and filtering, drying and roasting the obtained solid to obtain the defective zeolite molecular sieve rich in hydroxyl nests. The organic silicon source is alkylsiloxane. Alkylsiloxane is introduced in the process of constructing a framework of the molecular sieve, part of Si-C bond connection is formed, then C is burnt out in the roasting process of the molecular sieve, so that a single T-site framework point defect of the molecular sieve is formed, the hydroxyl nests are formed, the point defect almost has no influence on the crystallinity of the material, and the integrity of the molecular sieve framework is maintained to a great extent; and in the synthesis process, the defect degree of the molecular sieve can be relatively accurately controlled by controlling the variety and content of alkylsiloxane, so that the defect type zeolite molecular sieve rich in hydroxyl nests is obtained.

Description

technical field [0001] The invention belongs to the field of aluminosilicate zeolite synthesis, and in particular relates to a method for synthesizing a defective zeolite molecular sieve rich in hydroxyl nests. Background technique [0002] Zeolite molecular sieves are the most widely distributed inorganic microporous materials in nature. Since the Swedish scientist Cronstedt first discovered natural zeolite in 1756, due to its unique molecular sieving ability and good adsorption performance, it has attracted extensive attention from scientific researchers and has gradually been applied in people's actual production and life. Although natural zeolites have the characteristics of various types, wide distribution, large reserves and low cost, they have many impurities and low purity, which limits large-scale industrial applications. Therefore, the artificial synthesis of zeolites has become a new research direction. In the late 1940s, Barrer, an outstanding chemist in the fie...

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Problems solved by technology

At present, the more commonly used method is to prepare a zeolite molecular sieve containing defect sites by post-modification method of removing part of the skeleton aluminum or silicon by immersing the molecular sieve matrix in acid / alkaline solution, but how to precisely control The location and size of defect sites without disrupting the topology of the molecular sieve framework is a major challenge in the synthesis of defect-rich molecular sieves

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