摘要
考察了 K2 O-Al2 O3-Si O2 -TPABr(四丙基溴化铵 ) -H2 O体系中水热合成制备 ZSM-5分子筛时各因素对晶粒大小和形貌的影响。降低投料硅铝比、增加 K+ 含量、使用碱性较弱的 K2 CO3或升高晶化温度都能促进产品 ZSM-5分子筛晶粒的增大。提高投料硅铝比或引入 NO- 3易使产物形貌趋于球形。采用晶化前预老化的方法 ,可以方便地制备出不同晶粒大小 ( 1 .0～ 4 0 μm)且不含微晶、无微晶聚集体的产品。
Factors affecting the hydrothermal crystallization of zeolite ZSM-5 in K2O-Al2O3-SiO2-TPABr (tetrapropyl ammonium bromide) -H2O aluminosilicate gels system were studied. The high crystalline ZSN-5 zeolites of larger size were obtained from these gels, and their crystal morphology tended to transform from spherulite to euhedralite and grew larger when increasing either Al2O3 content or crystallization temperature or replacing KOH by less alkaline K2CO3. Oxydation such as NO3- played a role in preventing the formation of euhedralite in richer alumina recipe. Compared with seeding, a combination of aging and crystallization was more facile in tailoring of crystal size from 1.0 to 40 μm. The results show that the aged gel does not have the structural characteristics of ZSM-5 crystallite.
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2001年第2期24-29,共6页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
国家自然科学基金!资助项目 ( 2 9973 0 17
2 973 3 0 70)
关键词
ZSM-5分子筛
氧化钾
晶粒粒度
晶体形貌
合成
Aging of materials
Crystal structure
Crystallization
Hydrothermal synthesis
Morphology
Silica gel
