Synthesis method of silicoaluminophosphate molecular sieve SAPO-34

Abstract

The invention provides a synthesis method of a silicoaluminophosphate molecular sieve SAPO-34, belonging to the field of catalyst preparation methods. The method comprises the following steps: by using a recovered mother solution of a previously synthesized sample as the volume consumption required by synthesis, adding a phosphorus precursor into the recovered mother solution, uniformly mixing, slowly adding an aluminum precursor, and sufficiently stirring uniformly; adding a silicon precursor, sufficiently stirring, and regulating the pH value of the colloid to 6.0-7.0 with an organic template while stirring; and sufficiently stirring uniformly, crystallizing in a crystallizing kettle at 160-220 DEG C for 0.5-100 hours, centrifuging, washing, and drying to obtain the SAPO-34 molecular sieve catalyst. The method is novel, has the advantages of high efficiency and favorable repetitiveness, greatly lowers the synthesis cost, effectively avoids the environmental pollution caused by mother solution discharge, and implements circular and efficient utilization of the raw material.

Description

technical field [0001] The invention belongs to the field of catalyst preparation methods, and in particular relates to a synthesis method of silicoaluminophosphate molecular sieve SAPO-34. Background technique [0002] In 1984, the United States Union Carbide Corporation (UCC) developed a series of silicoaluminophosphate molecular sieves (SAPO-n, n represents the structural model). One of the most eye-catching is SAPO-34 molecular sieve. SAPO-34 molecular sieve made of PO 4 , AlO 4 and SiO 4 The tetrahedrons are connected with each other; it has an elliptical cage and a three-dimensional pore structure composed of oxygen eight-membered rings. The shape of the oxygen eight-membered ring may be oval, circular or wrinkled, and the size of the pore varies with the shape of the oxygen eight-membered ring, but the effective diameter of the pore remains between 0.43 and 0.50 nm. The pore volume is 0.42cm3 / g, the space symmetry group is R3m, it belongs to the trigonal crystal ...

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Problems solved by technology

These templates are generally expensive and the cost of synthesis is too high, which is not conducive to large-scale industrial production and promotion.

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