最低硅铝比八面沸石MAX合成条件的研究

Studies on Synthesis Conditions of Maximum Aluminum X(MAX)

研究了SiO2/Al2O3为2.0的LSX（又称 MAX）的合成条件．结果表明，对于 MAX体系，适合的老化温度为 70℃，老化时间为6 h．老化温度不仅影响反应速度，而且还影响诱导期产生晶核的类型，从而影响产物的纯度．对原料配比的研究表明，合成MAX的体系对水摩尔比的变化相当敏感．由于MAX体系的硅铝反应完全，便于原料中碱的回收和利用，从而可降低生产成本并减少对环境的污染．

Abstract Low-silica X, especially Maximum Aluminum X(so called for its lowest molar ratio SiOz to A12O3 are promising for their prospects of application. We synthesized MAX and studied its synthesis conditions. The results showed that the most appropriate ageing temperature was 70 'C and ageing time was 6 h. Ageing temperature not only played an important role in shortening the overall time of the synthesis, but also determined the purity of products by influencing the types of nuclei formed during the induction period. Pure MAX could be obtained only within a rather narrow range of composition. The experiments showed that the mother liquid was easily reusable as alkaline source which made the manufacture of MAX more economic and environment-friendly.