氟硅酸铵同晶置换改性ZSM-22分子筛的催化性能  

Catalytic Properties of(NH_4)_2SiF_6-Modified ZSM-22 Zeolite

作　　者：王瑜[1] 吴伟[1] 李程[1] 杨杰[1] 周亚静[1] 

机构地区：[1]黑龙江大学化学化工与材料学院黑龙江省普通高校高效转化的化工过程与技术重点实验室,黑龙江哈尔滨150080

出　　处：《石油学报（石油加工）》2011年第5期681-686,共6页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家自然科学基金(21076065);中俄政府间合作项目(CR12-43)资助

摘　　要：分别采用不同浓度的(NH4)2SiF6水溶液对ZSM-22分子筛进行同晶置换改性,并采用XRD、N2吸附-脱附、NH3-TPD、Py-IR、29Si MAS NMR对同晶置换改性前后的分子筛进行了表征,考察(NH4)2SiF6改性对分子筛孔道结构及酸性的影响。将改性前后的分子筛用浸渍法制备了0.5%Pd/ZSM-22双功能催化剂,并在连续微型固定床反应装置上考察了其对正癸烷(n-C10)加氢异构化反应的催化性能。结果表明,(NH4)2SiF6改性选择性地脱除了分子筛的部分强酸中心,有效地抑制了正癸烷的裂化反应。用0.3mol/L(NH4)2SiF6溶液改性后的分子筛制备的Pd/ZSM-22催化剂的加氢异构化反应活性和异构化选择性均得到提高。Crystal replacement modification to ZSM-22 zeolite was made in（NH4）2SiF6 aqueous solution of different concentrations.The parent and（NH4）2SiF6-modified ZSM-22 zeolites were characterized by X-ray diffraction,N2 adsorption-desorption,29Si MAS NMR,NH3 temperature-programmed desorption and FT-IR spectroscopy of adsorbed pyridine,to investigate the effect of（NH4）2SiF6 modification on the structure of pores and acidity of HZSM-22 zeolite.The hydroisomerization of n-decane over Pd supported on the ZSM-22 and modified ZSM-22 was carried out,respectively.The results showed that part of strong acid sites of HZSM-22 were removed selectively by（NH4）2SiF6 modification,and the cracking of n-decane was effectively suppressed.The conversion of n-decane and the isomerization selectivity were increased over the bifunctional catalyst Pd/ZSM-22 modified by 0.3mol/L（NH4）2SiF6 aqueous solution.

关 键 词：ZSM-22分子筛 正癸烷 双功能催化剂 加氢异构化 氟硅酸铵改性 

分 类 号：TQ032.41[化学工程]