Effect of Preparation Conditions on the Structure and MTO Activity of SAPO-34 Molecular Sieve

The hydrothermal method was used to synthesize SAPO-34 molecular sieve. XRD analysis and micro-reverse evaluation showed that changing the material ratio may form pure SAPO-5 molecular sieve, SAPO-34 molecular sieve, SAPO-5 and SAPO-34 mixed crystal or amorphous material. The MTO catalytic properties of the products are also different; although different template agents can induce the production of SAPO-34 crystal nuclei and synthesize pure SAPO-34 crystals, the molecular sieves synthesized with different template agents have obvious crystal structure and catalytic activity. The difference is that SAPO-34 synthesized with triethylamine (Et3N) as a template has better catalytic performance and crystal stability than SAPO-34 synthesized with diethylamine (DRA) as a template; the calcination process has a significant degree of perfection of the crystals. Effect, and may also change the unit cell size, so that the XRD diffraction peak position of the crystal shifts