The pore architecture and acidity of zeolite materials play crucial roles in the activity and selectivity of catalytic reactions. Herein, hierarchical SAPO-11 molecular sieve microspheres with uniform intercrystalline mesoporosity (ca. 4.3 nm) and tunable acidity were synthesized via dry-gel conversion (DGC) of a silicoaluminophosphate–organosilane composite. The products were comprehensively characterized using multiple techniques, including XRD, SEM, TEM, N₂ adsorption–desorption, NH₃-TPD, pyridine-adsorbed IR (Py-IR), TG and ²⁹Si MAS NMR measurements. It is revealed that the products' acidity can be precisely tuned in a wide range by simply adjusting the water content used in the synthesis. The growth of such hierarchical SAPO-11 underwent a rearrangement of the mesopores: the original mesopores (ca. 17 nm) of the precursor were collapsed at the initial stage of crystallization and the final mesopores of the products were directed by the organosilane. More importantly, the Pt/hierarchical SAPO-11 catalysts exhibited enhanced isomerization selectivity in the hydroisomerization of n-dodecane, attributed to their excellent diffusion properties resulting from the hierarchical pore network. This work demonstrates a facile approach to synthesize hierarchical zeolites with tunable acidity, which is beneficial for catalytic reactions involving bulky molecules.

中文翻译：

---

具有可调酸度的高介孔SAPO-11分子筛：正十二烷加氢异构化反应的简便合成，形成机理和催化性能

沸石材料的孔结构和酸度在催化反应的活性和选择性中起着至关重要的作用。本文中，通过硅铝磷酸盐-有机硅烷复合材料的干凝胶转化（DGC）合成了具有均匀晶间介孔（约4.3 nm）和可调酸度的分级SAPO-11分子筛微球。使用多种技术对产品进行了全面表征，包括XRD，SEM，TEM，N ₂吸附-解吸，NH ₃ -TPD，吡啶吸附的IR（Py-IR），TG和²⁹Si MAS NMR测量。结果表明，只需调节合成中使用的水含量，即可在宽范围内精确调节产品的酸度。这种分级SAPO-11的生长经历了中孔的重排：在结晶的初始阶段，前体的原始中孔（约17 nm）塌陷，产物的最终中孔由有机硅烷引导。更重要的是，Pt /分层SAPO-11催化剂在n的加氢异构化中表现出增强的异构化选择性-十二烷，归因于其由分层孔隙网络产生的出色扩散性能。这项工作证明了一种容易的方法来合成具有可调酸度的分级沸石，这对于涉及大分子的催化反应是有益的。