氟氯有机化合物对HZSM-5分子筛改性过程中氟和氯的作用  

EFFECT OF FLUORINE AND CHLORINE DURING THE MODIFICATION OF HZSM-5 ZEOLITE WITH ORGANIC FLUOROCHLORO-COMPOUNDS

作　　者：邱平[1] 臧雅茹[1] 陶克毅[1] 高峰[1] 李赫晅 

机构地区：[1]南开大学化学系

出　　处：《Chinese Journal of Catalysis》1993年第6期466-472,共7页催化学报（英文）

基　　金：国家自然科学基金

摘　　要：利用XRD,MAS NMR,IR和XPS等手段研究了CF_(4-n)Cl_n改性的HZSM-5分子筛的体相和表面结构的变化。结果表明,改性过程中F和Cl均能使HZSM-5脱铝和脱硅。Cl可以使沸石骨架SiO_2/Al_2O_3升高,而F除使沸石骨架脱铝外,还会极化其晶格。F比Cl更容易在沸石表面富集。F和Cl是通过取代O或OH与沸石表面Si或Al作用的。改性后的沸石表面有数种含氟表面物种存在。The activity, stability and selectivity of zeolites could be improved by the modification with fluorochloro-compounds. However, the effect of F and Cl on modification is still unknown. The bulk and surface composition of HZSM-5 zeolite modified with CF4-nCln were characterized with XRD, MAS NMR, IR and XPS. The results showed that both fluorine and chlorine could make HZSM-5 zeolite dealuminized and desi-liconized. Chlorine could make the zeolite framework dealuminized, and fluorine not only dealuminized the zeolite framework, but also polarized its crystal. Both of them acted with Si or Al in the manner of substitution of F or Cl for O or OH on the zeolite surface, and fluorine enriched on the surface more easily than chlorine. Several kinds of surface fluoride species were formed after modification of HZSM-5 zeolite.

关 键 词：HZSM-5 分子筛 改性 氟氯有机化物 

分 类 号：O643.36[理学—物理化学]