Method for synthesizing silicoaluminophosphate molecular sieve SAPO-11 at normal pressure

Abstract

The invention provides a method for synthesizing a silicoaluminophosphate molecular sieve SAPO-11 at normal pressure. The method is characterized in that the main process comprises the following steps of 1) preparation of eutectic mixture: fully grinding and mixing quaternary ammonium salt and organic acid or organic alcohol in a mortar with a mol ratio of 0.1 to 1.0; placing the mixture in a beaker, heating the beaker at a temperature of 80-180 DEG C to melt the mixture into transparent liquid, so as to obtain the eutectic mixture; 2) preparation of crystallization reaction mixture: adding phosphorus source, silicon source, mineralizing agent, template agent and aluminum source into the molten eutectic mixture in sequence, uniformly stirring the mixture at a mixing temperature range from 80 to 150 DEG C to form a reaction mixture; 3) crystallizing the reaction mixture prepared by step 2); and 4) water cooling the reactant reacted in step 3) to a room temperature, washing and separating the mixture, and drying and baking the washed and separated mixture, wherein the washed filtrate is recovered after rotary evaporation.

Description

technical field [0001] The invention belongs to the field of inorganic synthesis, and relates to a method for synthesizing molecular sieves; more precisely, it relates to an ionothermal synthesis method of silicoaluminophosphate molecular sieve (SAPO-11) in eutectic mixture. Background technique [0002] Aluminum phosphate molecular sieves are a new generation of molecular sieves (USP4310440) developed by Union Carbide in the early 1980s following the silica-alumina molecular sieves. AlPO 4 -11 molecular sieve (skeleton topological structure code named AEL), which contains a one-dimensional ten-membered ring straight pore structure, with an elliptical orifice and a size of 0.39×0.63 nm. The silicoaluminophosphate SAPO (MAPO) molecular sieve introduced by silicon (or other metal heteroatoms M) has an acidic site in the framework, thus expanding the use of the molecular sieve, especially in the alkane hydroisomerization reaction, carrying noble metals SAPO-11 molecular siev...

AI Technical Summary

Problems solved by technology

[0004] However, ionic liquids are not very convenient to synthesize, and the price is relatively high; eutectic mixtures have similar properties to ionic liquids, and can also be used as solvents for the synthesis of molecular sieves, which are convenient and cheaper to prepare

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