低硅铝比ZSM-48分子筛合成及其正构十二烷临氢异构催化性能研究

Synthesis and hydroisomerization performance of n-C₁₂ over ZSM-48 molecular sieve with low silicon-aluminum ratio

摘要: 通过静态水热合成法，溴化六甲二铵作为结构导向剂合成出系列低硅铝比的ZSM-48沸石分子筛（Si/Al < 100），所合成样品中最低硅铝比为38.6（ICP-AES），这将拓宽ZSM-48高硅沸石分子筛的应用范围。制备Pt负载双功能催化剂，用于正构十二烷临氢异构催化反应。结果表明，硅铝比的改变可以影响催化剂的活性，投料硅铝比为70的双功能催化剂具有最优的催化性能，但硅铝比改变对异构产物的分布没有明显的影响，其异构产物以支链在中间位的异构体为主。

Abstract: A series of ZSM-48 zeolites with low Si/Al ratios (Si/Al < 100) were synthesized by hydrothermal synthesis method using hexamethydiammonium bromide as the structure directing agent. ICP-AES results showed that the Si/Al ratio of the synthesized sample was as low as 38.6, indicating the zeolite could be widely used. Pt supported on ZSM-48 with different Si/Al ratios were used for n-paraffin hydroisomerization. The catalytic reaction results showed that Pt/HZSM-48 with Si/Al ratio of 70 exhibited the best catalytic performance. However, the distribution of isomers had not been affected by Si/Al ratio of the ZSM-48, and the central-branched isomers were the main hydroisomerization products.