Gou Ming-Lei, Ru Xuan, Yang Yongli, Liu Zhen, Peng Shuge
School of Chemistry and Chemical Engineering, Henan University of Science and Technology Luoyang Henan 471023 PR China
RSC Adv. 2025 Jun 2;15(23):18266-18274. doi: 10.1039/d5ra03351a. eCollection 2025 May 29.
A facile strategy affording hierarchical nano-ZSM-5 zeolites with high yields (approaching 100%) and crystallinity using a seed-assisted dry-gel conversion (SA-DGC) method is developed. Only a small amount of tetrapropylammonium hydroxide (TPAOH) was used for the synthesis of protozeolite seeds without involving the use of any structure-directing agents (, SiO/TPA = 30). A very small amount of water (, 1.0 mL) was required for crystallization conditions. Protozeolite seeds with a size not exceeding 20 nm can provide a high-activity nucleus for zeolite crystallization, and the precursor is not in direct contact with water and freely migrates, resulting in the formation of nano-zeolites (100-200 nm) around the microregion of the seeds during steaming treatment. Owing to the high-quality nanosized crystals, the as-prepared hierarchical nano-ZSM-5 zeolites exhibit outstanding performance in the rearrangement of styrene oxide and its derivatives compared with conventional ZSM-5 zeolites.
开发了一种简便的策略，即使用种子辅助干凝胶转化（SA-DGC）方法，以高产率（接近100%）和结晶度制备分级纳米ZSM-5沸石。在合成原沸石种子时仅使用少量的氢氧化四丙基铵（TPAOH），且不使用任何结构导向剂（SiO/TPA = 3）。结晶条件只需极少量的水（1.0 mL）。尺寸不超过20 nm的原沸石种子可为沸石结晶提供高活性晶核，且前驱体不与水直接接触并能自由迁移，从而在蒸汽处理过程中在种子的微区周围形成纳米沸石（100-200 nm）。由于具有高质量的纳米晶体，与传统ZSM-5沸石相比，所制备的分级纳米ZSM-5沸石在环氧苯乙烷及其衍生物的重排反应中表现出优异的性能。
