摘要
运用二元碱氮置换吸附红外光谱法、分子筛孔径分布测定技术、XPS技术,考察了丝光沸石表面酸性与孔结构的相互关系、钯在丝光沸石上分布情况和价态及其与沸石的相互作用。结果表明,随着丝光沸石脱铝程度的增加,表面出现大量不规整晶格,存在较多的次级孔道。强质子酸中心主要分布在它的“外表面”。钯在其表面富集,并与“外表面”上的质子酸中心协同作用,促进了轻质烷烃异构化反应。
The relationship between surface acidity and pore structure of mordenite was investigated by FT-IR of binary basic nitrogen compounds displacement, BET and pore size distribution calculated using MP method. The distribution, surface state and interaction of palladium on mordenite were studied by XPS. It is shown that large number of irregular framework and secondary pore will emerge on the surface of mordenite as its dealuminized extent increases. The stronger Bronsted acid site is mainly distributed on the external surface, the more palladium exists on the surface of mordenite. An isomerization of light paraffin is promoted by the interaction between palladium and Bronsted acid site on external surface of mordenite.
关键词
沸石
孔分布
钯
催化剂
熔烃
汽油
zeolite
pore size distribution
acidity
palladium
secondary pore
catalysis
