Preparation method of FER (Ferritin) zeolite molecular sieve with high silica-alumina ratio

Abstract

The invention discloses a preparation method of an FER (Ferritin) zeolite molecular sieve with high silica-alumina ratio. The method comprises the following steps of: first, dissolving an aluminum source in a mixed liquid of sodium hydroxide, alkali and alkaline earth salt of weak acid; after adding the aluminum source, stirring and dispersing for a period of time by strong magnetic force at room temperature; mixing uniformly dispersed aluminum source and aluminum source liquid at room temperature to form glue; adding the FER zeolite molecular sieve as crystal seeds; after uniformly stirring and mixing at room temperature by strong force, transferring to a reaction crystallization kettle; crystallizing for 0.5-3 days by 130-170 DEG C microwave; and conventionally, filtering, washing and drying to obtain the sieve. According to the preparation method provided by the invention, expensive organic amine is not used as a structure-directing agent, and the FER zeolite molecular sieve is used as a crystal seed for microwave crystallization in an inorganic system with low alkalinity and high salinity. The crystallization degree and purity of products prepared are high, the silica-alumina ratio is easy to regulate, the synthetic cost is low, the environmental-pollution less, and the method is convenient for industrial large-scale production.

Description

technical field [0001] The invention relates to the synthesis of zeolite molecular sieves, in particular to a synthesis method of zeolite molecular sieves with FER topological structure. Specifically, without using an organic amine as a structure-directing agent system, by adding a seed crystal as a nucleation accelerator, in the presence of an alkali or an alkaline-earth metal inorganic salt, the synthetic route of using microwave heating is used to rapidly prepare a silicon-aluminum ratio modulation FER microporous zeolite molecular sieve. Background technique [0002] Ferrierite FER was originally a natural mineral, and ZSM-35 molecular sieve, which was first artificially synthesized by Plank et al. in 1977, is a kind of FER family. The structure of FER is a two-dimensional channel system composed of ten-membered rings of 0.438×0.55nm and eight-membered rings of 0.34×0.48nm. Due to the narrower pore free diameter and stronger surface acidity than ZSM-5, it has good cata...

AI Technical Summary

Problems solved by technology

Due to the introduction of a large amount of organic templates in the above synthetic methods, a large amount of wastewater containing high-concentration templates will be produced in the zeolite molecular sieve washing process, which will cause a lot of pollution to the environment and waste of resources (Microporous and Mesoporous Materials 119 (2009) 60– 67; Phys. Chem. Chem. Phys., 2001, 3, 4164-4169; ACS Catal. 2013, 3, 617-621; Chemical Acta, 2003, 61, 835-839)

[0004] In addition to the introduction of structure-directing agents, many zeolite molecular sieve synthesis experts are also committed to the research of template-free zeolite molecular sieve synthesis, such as USP3,992,446, USP4,016,245, USP4,088,739, USP4251499, etc., all adopt the synthesis method without using templates , but the template-free method has disadvantages such as high reaction temperature, long reaction time, narrow synthesis interval, and low silicon-aluminum ratio of FER molecular sieve (Top.Catal. 2009, 52, 67; J. Mater. Chem. , 2011,21, 9494-9497; J. Am. Chem. Soc., 2012, 134, 11542), thus greatly limiting the industrial application of FER

Images