Abstract:

Molecular sieves have been widely used as catalyst or adsorbent in petroleum refining and fine chemical industries. The synthetic chemistry of molecular sieve has advanced significantly in recent years, and the role of seed crystal in zeolite synthesis has become a research hotspot. Here the research progress of the role of seed in molecular sieve synthesis is reviewed and the impacts of seed are concluded to five aspects: accelerating crystallization rate, broadening the silica to alumina ratios of product, regulating product morphology, substituting organic templates and other functions. The focus is the role of seed crystal in the formation of molecular sieves with special morphology and the substitution of seed for organic template agent. According to the nucleation and growth mechanisms of molecular sieve, the principles of different effects of seed crystal in the synthesis process were analyzed, and it was revealed that the reduction of the activation energy of molecular sieve nucleation by seed crystal was the basis for its different effects. From the perspective of clean production, it is proposed that the specific structural changes of seed crystal in the process of molecular sieve synthesis and the synthesis of molecular sieve with high performance using seed crystal instead of organic template agent will become the focus of future research.

Key words: molecular sieve, zeolites, synthesis, nucleation, seed crystal

摘要：

分子筛材料作为催化剂或吸附剂已经在石油炼制和精细化工领域中实现广泛应用。近年来，分子筛合成化学研究取得了长足进展，晶种在分子筛合成中的作用成为本领域研究热点。本文将晶种在分子筛合成中的作用概括为5个方面：加快晶化速率、拓宽产物硅铝比范围、调变产物形貌、替代有机模板剂和其他作用，重点聚焦晶种导向特殊形貌分子筛的形成及晶种对有机模板剂的替代作用。从分子筛成核与生长机理出发，剖析了晶种在分子筛合成过程中不同作用的原理，揭示了晶种降低分子筛成核活化能是其发挥多种不同作用的基础。从清洁生产的角度出发，提出晶种在分子筛合成过程中具体的结构变化和晶种替代有机模板剂合成高性能分子筛材料将成为未来研究重点。

关键词: 分子筛, 沸石, 合成, 成核, 晶种