小晶粒FeZSM-5分子筛合成过程中晶粒大小和分布的控制

Control of Crystal Size in the Synthesis of Small Crystalline FeZSM-5

用水热法合成了晶粒大小在 2 0 0～ 10 0 0nm的小晶粒FeZSM -5分子筛 ,并对碱度、温度、模板剂和初始凝胶浓度等对分子筛晶粒大小和分布的影响进行了研究。结果表明 ,较高的碱度和反应物浓度有利于小晶粒杂原子分子筛的合成 ;程序升温法合成的分子筛颗粒小、粒度均匀 ,抑制了二次成核过程 ;模板剂的种类对FeZSM -5分子筛的尺寸也有显著影响 ,分别以正丁胺、乙二胺和己二胺为模板剂合成了FeZSM -5分子筛 ,晶粒大小顺序为正丁胺 <己二胺 <乙二胺。

FeZSM-5 zeolites with small crystal sizes(200～1000 nm) were synthesized hydrothermally under different conditions.The influences on crystal size and size distribution of alkalinity,templates,temperature and initial gel concentration were investigated systematically.The results suggest that high alkalinity and concentraion of the reaction mixture are favorable for the formation of small crystallites,and the pre aging of the reaction mixture at lower temperature give uniform small crystal size product owing to the suppression of secondary nucleation process.Templates can also influence the size of the final product. [