Preparation method and application of SAPO-34 molecular sieves with flaky morphology

The invention belongs to the technical field of preparation of molecular sieves and particularly relates to synthesis of SAPO-34 molecular sieves with flaky morphology and an application of the SAPO-34 molecular sieves in preparation of methanol to olefin. The molecular sieves are subjected to one-step hydrothermal synthesis, a double-template agent is mixed with an aluminum source, a silicon source and a phosphorus source, hydrothermal crystallization is performed, and the SAPO-34 molecular sieves are prepared. The synthesized SAPO-34 product adopts the flaky morphology, the crystal size ranges from 0.5 mu m to 2 mu m, and the thickness ranges from 50 nm to 200 nm. The synthesis method is simple, other solvents, surfactants and the like do not need to be added. The prepared product has high low-carbon olefin selectivity, especially high ethylene selectivity in a methanol-to-olefin reaction. 本发明属于分子筛制备技术领域，具体涉及种片状形貌的SAPO-34分子筛的合成及其在甲醇制烯烃上的应用。该分子筛采用步法水热合成，将双模板剂与铝源、硅源及磷源混合，水热晶化制得。所合成的SAPO-34产品为片状形貌，其晶体粒度尺寸为0.5～