纳米级SAPO-34分子筛的制备及其在甲醇制烯烃反应中的应用进展

SAPO-34分子筛被广泛应用于甲醇制烯烃(MTO)反应中,目前已实现工业化应用。传统的SAPO-34分子筛在催化过程中容易发生积碳、焦化,导致分子筛失活,单程使用寿命短等问题。纳米级SAPO-34分子筛具有较小晶体尺寸,较高比表面积,减少扩散限制、增强催化剂活性中心和抗积炭能力。在MTO中催化性能相较于传统分子筛更佳。本文从晶种辅助、增加添加剂、双模板剂和优化结晶条件等角度,介绍纳米级SAPO-34的制备方法,进一步研究分析了各不同条件对纳米晶体尺寸的影响,同时对不同纳米尺寸的纳米级SAPO-34在MTO中催化性能进行了探讨。提出了目前研究的问题及未来发展的方向。

Progress in preparation of Nano-scale SAPO-34 Molecular sieves and application of methanol to olefins

SAPO-34 molecular sieve is widely used in the reaction of methanol to olefin (MTO). Traditional SAPO-34 molecular sieve is prone to carbon deposition and coking in the catalytic process, which leads to molecular sieve deactivation and short service life. Nano-scale SAPO-34 molecular sieves have smaller crystal size, higher specific surface area, less diffusion limitation, stronger catalyst activity center and anti-carbon deposition ability. In this paper, the preparation methods of nanometer SAPO-34 were introduced from the perspectives of seed assist, additive addition, double template agent and optimization of crystallization conditions, and the effects of different conditions on the size of nanometer crystals were further studied and analyzed. Meanwhile, the catalytic performance of SAPO-34 with different nanometer size in MTO was discussed. The current research problems and future development directions are put forward.