小粒径SAPO-11分子筛合成的研究进展

传统的SAPO-11分子筛颗粒尺寸较大，将其作为烷烃加氢异构化双功能催化剂的载体时，会增加烷烃分子在孔道内的停留时间，并降低载体的孔体积和酸中心利用率。小粒径SAPO-11分子筛孔道长度短，更便于烷烃分子扩散，并且具有更多暴露的孔口，提高了催化活性位的可及性。本文针对传统水热法合成的SAPO-11分子筛因颗粒尺寸较大而降低其孔体积和酸中心利用率，以及增加烷烃分子在孔道内的停留时间，使得烷烃分子在孔道内酸性位的作用下发生过度裂化等问题，综述了小粒径SAPO-11分子筛制备方法的最新研究进展及其优缺点，介绍了小粒径SAPO-11分子筛合成过程中的影响因素，并分析了小粒径SAPO-11分子筛合成技术中的关键要点和亟待解决的问题以及未来的发展趋势，指出未来应着重于具有良好热稳定性的小粒径多级孔SAPO-11分子筛的研究，并且应注重实现合成过程的方法绿色化、模板剂绿色化和溶剂绿色化。

Research progress in the synthesis of small particle-size SAPO-11 molecular sieves

The particle size of conventional SAPO-11 molecular sieve is large. When it is used as the support for a bifunctional catalyst for alkane hydroisomerization, it will reduce the utilization ratio of the pore volume and acid center of the support, and increase the residence time of alkane molecules in the pores. SAPO-11 molecular sieve with small particle size has short pore length, which makes it easier for alkane molecules to diffuse, and has more exposed pores, which improves the accessibility of catalytic active sites. Aiming at the problem that SAPO-11 molecular sieve synthesized by conventional hydrothermal method has a large particle size, which reduces the utilization ratio of pore volume and acid center, and increases the residence time of alkane molecules in the pores, so that the alkane molecules undergo cracking reactions under the further action of acid sites in the pores. The latest research progress of the preparation methods of small-particle SAPO-11 molecular sieves and their advantages and disadvantages were reviewed, and the influencing factors in the synthesis of small-particle SAPO-11 molecular sieves were introduced. The key points, urgent problems to be solved and development trends of the synthesis technology of small-particle SAPO-11 molecular sieves were analyzed, and pointed out that the future research should focus on the SAPO-11 molecular sieves with small particles and hierarchical pores, which also have a good thermal stability, and realize the greening of the synthesis process, the greening of the template agent and the greening of the solvent.