偏高岭土基磷酸硅铝分子筛合成及其催化性能研究

以偏高岭土兼作Al、Si源，H3PO4作磷源，十六烷基三甲基溴化铵－三乙醇胺为复合模板剂，采用分段晶化的方法制备磷酸硅铝分子筛。利用X射线衍射分析、扫描电镜、XPS及NH3-TPD等手段对产物进行了表征。实验结果表明：产物为柱状的磷酸硅铝分子筛，其晶粒尺寸大约为20 μm×5 μm×5 μm，其晶体结构中P:Al:Si＝1:1.19:0.67（摩尔比），硅含量较高；采用分段晶化方式制备的SAPO-5分子筛的总酸量为578.0 μmol/g高于一段晶化方式制备的SAPO-5分子筛的总酸量；采用分段晶化生成的SAPO-5分子筛的催化正丁烷异构化反应初始活性可达到24.8 %，远高于一段晶化制备的SAPO-5分子筛的初始活性14.1 %。

Synthesis And Catalysis Performance Of Silicoaluminophosphate Molecular Sieves From Metakaolin

Silicoaluminophosphate(SAPO–5)molecular sieves were synthesized by the two step crystalline hydrothermal method,using metakaolin witha certain degree of activity as the silicon and aluminum sources,phosphoric acid as the phosphorus source and triethylamine com-bined with hexadecyl trimethyl ammonium bromide as the template agents.The silicoaluminophosphate molecular sieves were characterized by XRD,SEM,XPS and NH3-TPD analysis.The results show that the SAPO–5 has a pillar-like morphology with the size of about 20 μm×5 μm×5 μm.The ratio of P:Al:Si is 1:1.19:0.67 in its crystal structure, the content of Si is high. The total acidimety fo the SAPO–5 is 578.0 μmol/g , hihger than that of prepared by one step crystalline hydrothermal method.And its initial catalysis character performance on normal butane isomerization reaction reach 24.8 %, higher than that of prepared by one step crystalline hydrothermal method.