NH4+-TPA+-SiO2-Al2O3-H2O体系中ZSM-5沸石分子筛合成的研究

七十年代初期美国Mobil公司首先研究成功的ZSM-5沸石分子筛,由于它具有独特的孔道结构,对烷基化,异构化,选择裂化和甲醇合成汽油等反应具有独特的催化性能,目前已成为被普遍重视的新型催化剂材料^1-4]。

ASTUDY ON THE SYNTHESIS OF ZEOLITE ZSM-5 IN THE SYSTEM OF NH4+-TPA+-SiO2 -Al2O3 -H2O

Zeolite HZSM-5 has been found to possess excellent quality as a catalyst. It can usually be prepared by exchange reaction between HCl or NH₄ Cl and NaZSM-5.The product Thus obtained is HZSM-5 or NH₄ZSM-5 respectively; the latter is capable of being transformed into HZSM-5 by heating. We report here a new procedure for synthesis of Zeolite HZSM-5. The NH₄ ZSM-5 is prepared in the systems of NH₄⁺-tetrapropylamonium bromide without the presence of NaOHand reaction of ion exchange. The reaction temperature from 1.00℃ to 160℃ is good enough for the synthesis of NH₄ ZSM-5; the range of SiO₂/Al₂O₃ ratio of the product is from 52to 180.The lower mole limit of TPABr used is 0.02 mole. The thermal stability of the product is good. It is shown by curves of TGAand DTAthat there is no phase transform peak in the range of temperature up to 1200℃. Its scanning electron micrographs,X-ray diffraction patterrn and the results of adsorption measurement are given.