作　　者： ; ; ; ;

机构地区： 华东理工大学

出　　处： 《石油化工》 2006年第10期948-952,共5页

摘　　要： 采用三段晶化法合成了MCM-22分子筛,研究了MCM-22分子筛的热稳定性,分别用盐酸、NaOH和铵盐溶液在沸腾条件下处理MCM-22分子筛6h,考察MCM-22分子筛对酸、碱、铵盐的稳定性。实验结果表明,MCM-22分子筛的热稳定性较好,当焙烧温度达950℃时,MCM-22分子筛的相对结晶度下降30%,骨架结构基本保持不变;MCM-22分子筛的相对结晶度随盐酸浓度的增加而略有下降,但骨架结构保持不变,MCM-22分子筛具有良好的耐酸性;当c(NaOH)≤2mol/L时,MCM-22分子筛结构完全被破坏,成为无定形物,当c(NaOH)>3mol/L时,不仅原分子筛结构全部破坏,且形成了新的化合物,MCM-22分子筛的耐强碱性较差;MCM-22分子筛经1.5mol/L的NH4F溶液处理后,骨架结构完全被破坏,但对其他铵盐表现出较好的稳定性。 MCM-22 zeolite was synthesized by three-step crystallization method and its physicochemical properties were characterized by means of XRD, PTIR and TG-DTA. Its stability was investigated after calcination and after separate treatments in boiling acid, base and different ammonium salt solutions for 6 h. XRD results show that although relative crystallinity of MCM-22 zeolite deceases by 30% at most when calcination temperature range is within 550 ℃ to 950 ℃,its framework basically remains unchanged. In boiling media treatment, relative crystallinity of zeolite goes down slightly with increase of HCl solution concentration. When concentration of NaOH solution is 1 - 2 mol/L, zeolite turns into amorphous state, and new compounds form when NaOH solution concentration is more than 3 mol/L. After boiling in ammonium salt solutions, the framewok of MCM-22 zeolite does not change, but when treated with boiling NH4F solution, framewok of MCM-22 zeolite is destroyed completely.

关 键 词： 分子筛 稳定性 酸 碱 铵盐 催化剂

领　　域： [化学工程]