The formation of centrally branched iso-dodecane was controlled by absorption modes of alkene intermediates on ZSM-22, which included pore mouth type and key lock type. In this paper, we have designed and synthesized two kinds of ZSM-22 catalysts for selective formation of iso-dodecane with branched chain at more central positions from n-dodecane hydroisomerization. Aluminosilicate ZSM-22 was modified via carbonization of template to block the micropores and borosilicate ZSM-22 was synthesized. The characterization results and performance evaluation validated that micropore blockage could limit the pore mouth type at low reaction temperatures which favored the formation of iso-dodecane with side chain near the end of the carbon chain. Owing to the weak acid strength, higher temperatures, which favored the key lock mode, were needed to run the n-dodecane hydroisomerization over Pt/borosilicate ZSM-22. Both the two strategies for catalyst design achieved key lock adsorption mode and improvement of the selectivity for centrally branched iso-dodecane. Most importantly, weak acid sites on borosilicate ZSM-22 could catalyze double-bond isomerization reactions, which enhanced centrally branched iso-dodecane distribution up to more than 47%. Our research provides a prospective strategy for selective formation of centrally branched iso-alkanes and Pt/borosilicate ZSM-22 is expected to have potential applications in n-alkane hydroisomerization.

ZSM-22上烯烃中间体的吸收方式控制了中心支链异十二烷的形成，包括孔口型和键锁型。在本文中，我们设计并合成了两种ZSM-22催化剂，用于选择性地从n到更多中心位置形成带有支链的异十二烷。-十二烷加氢异构化。通过模板的碳化来改性铝硅酸盐ZSM-22，以封闭微孔，并合成了硼硅酸盐ZSM-22。表征结果和性能评估证实，微孔堵塞可以限制低反应温度下的孔口类型，这有利于在碳链末端附近形成带有侧链的异十二烷。由于弱酸强度，较高的温度，这有利于在按键锁定模式，还需要运行Ñ-Pt /硼硅酸盐ZSM-22上的十二烷加氢异构化。两种催化剂设计策略均实现了键锁吸附模式并提高了中心支化异十二烷的选择性。最重要的是，硼硅酸盐ZSM-22上的弱酸位可以催化双键异构化反应，从而将中心支链异十二烷的分布提高至47％以上。我们的研究为选择性形成中心支链异烷烃提供了前瞻性策略，并且Pt /硼硅酸盐ZSM-22有望在正构烷烃加氢异构化中具有潜在的应用。