亚微米FeAlMFI沸石合成、表征及甲醇转化性能

以硅溶胶、硝酸铁和硫酸铝为原料,四丙基溴化铵为模板剂,甲基纤维素(MC)为微反应器模板,采用水凝胶制约法合成亚微米FeAlMFI沸石。考察了晶化时间、晶化温度和甲基纤维素浓度等因素对合成沸石粒度的影响。利用XRD,ICP,LPSA等手段对样品结构和粒度尺度进行了表征,所合成的沸石为粒径100～200nm的FeAlMFI亚微米沸石。采用催化甲醇制低碳烯烃(MTO)的反应考察了ZSM-5和FeAlMFI沸石的催化性能,结果表明,亚微米FeAlMFI沸石具有较高的活性稳定性,其低碳烯烃选择性可达85.9%。

Preparation and Characterization of Submicron FeA1MFI Zeolite and Methanol Conversion Catalytic Performance

Submicron zeolites FeA1MFI were synthesized by hydrogel constraint synthesis method,with silica sol, ferric nitrate and aluminum sulfate being used as silicon, iron and aluminum sources, respectively, and TPABr as template agent, methyl cellulose as micro-reactor template. The factors that influence particle size were also discussed, such as crystallization time, crystallization temperature and MC. The structure and particle size of samples obtained were characterized by means of XRD, ICP and LPSA. The results indicate that the synthesized zeolite samples are submicron FeA1MFI zeolites, with 100-200 nm particle sizes. The catalytic performance of ZSM 5 and FeA1MFI zeolites was investigated by the methanol- to- olefins reaction. The results of methanol reaction tests show that submicron FeA1MFI zeolite catalyst exhibited a high active stability of methanol conversion and the selectivity to light olefins is increased significantly to 85.9 %.