Synthesis method of SAPO-34 molecular sieve with surface defects

Abstract

The invention provides a synthesis method of a SAPO-34 molecular sieve with surface defects. The method comprises the following steps: after mixing a silicon source, an aluminum source, a phosphorus source, a template agent and water according to the mol ratio of SiO2 to Al2O3 to P2O5 to R to H2O of (0.5 to 0.8) to 1 to (0.8 to 1.2) to (1 to 3) to (40 to 80), carrying out dynamic hydrothermal crystallization at the low temperature of 170 to 190 DEG C and under a short-time condition of 2 to 15h, so as to obtain a cubic-shape SAPO-34 molecular sieve with the surface defects. According to the technical scheme provided by the invention, the obtained SAPO-34 molecular sieve has the surface defects and excellent methanol to olefin catalytic performance.

Description

technical field [0001] The invention relates to a method for synthesizing a cubic shape SAPO-34 molecular sieve with surface defects, and belongs to the technical field of catalyst preparation. Background technique [0002] Ethylene and propylene, as basic organic raw materials in the modern chemical industry, can be used to produce various chemical products such as plastics, and their demand is increasing. The traditional diene production process is characterized by excessive dependence on petroleum resources. Under the background of unstable supply of petroleum resources and continuous price increase, the development of a new process route for producing ethylene and propylene has become a research focus. my country's energy structure is "rich in coal, short of oil, and low in gas", and the domestic process of methanol from coal is very mature, so the process of methanol to low-carbon olefins is of great significance to reduce dependence on oil and maintain my country's ene...

AI Technical Summary

Problems solved by technology

Therefore, the current methods for preparing SAPO-34 molecular sieves at home and abroad generally have defects such as high cost and complicated process, and the catalytic performance of the SAPO-34 molecular sieve thus prepared, for example, the ethylene selection of SAPO-34 molecular sieve in the MTO reaction Performance, reaction life and carbon capacity are not very good

In addition, if it is necessary to prepare a series of SAPO-34 molecular sieves with different grain shapes, it is necessary to change the template agent synthesized by the SAPO-34 molecular sieve, the way of feeding silicon-aluminum ratio, or the way of post-treatment modification. Obtaining different series of SAPO-34 molecular sieves with different grain shapes, the modulation process is cumbersome and complicated, and it is not easy to operate

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