Aluminophosphate molecular sieve AlPO4-34 and fluoride-free preparation method thereof

Abstract

The invention provides an aluminophosphate molecular sieve AlPO4-34 and a fluoride-free preparation method thereof and belongs to the field of synthesis and preparation of molecular sieves. The fluoride-free preparation method of the aluminophosphate molecular sieve AlPO4-34 comprises steps as follows: firstly, evenly mixing an aluminum source, water and a phosphorus source to obtain gel, and evaporating and concentrating the gel to obtain half-dry gel; then adding an organic template to the obtained half-dry gel, and evenly strring the mixture to obtain synthetized gel, wherein the phosphorus source is phosphoric acid, and the organic template is morpholine. According to the fluoride-free preparation method of the aluminophosphate molecular sieve AlPO4-34, under the condition that no HF (hydrofluoric acid) is added, common organic amine is used as the template, the content of water in the gel is controlled through evaporation and concentration, and the aluminophosphate molecular sieve AlPO4-34 is synthetized with the high crystallinity and the high yield.

Description

technical field [0001] The invention relates to the technical field of synthesis and preparation of molecular sieves, in particular to an aluminum phosphate molecular sieve AlPO 4 -34 and its fluorine-free preparation method. Background technique [0002] It has been nearly 30 years since the discovery of aluminum phosphate molecular sieve in 1982. The aluminum phosphate molecular sieves found now have more than 53 structures, and most of these molecular sieves are small-pore, medium-pore, and macro-pore structures, and of course there are some ultra-large microporous compounds. Among so many aluminum phosphate structures, AlPO 4 The -34 is in a class of its own. [0003] AlPO 4 -34 has a chabazite-like structure, and the eight-membered ring has open channels. The skeleton is interlaced by double six-membered rings to form a cage structure. At the same time, 1 / 3 of Al in the framework adopts six-coordination, and adjacent six-coordinated Als are connected through F bri...

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Problems solved by technology

[0006] The problem to be solved in the present invention is to form AlPO without fluorine 4 The crystallization of -34 is very sensitive to the presence of water, and the interference of water in its structure formation cannot be controlled only under hydrothermal conditions, resulting in the formation of molecular sieves with other structures

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