摘要
研究了不同锌含量的Zn/HZSM 5分子筛的表面酸性及其对正己烷芳构化反应的催化活性、选择性和稳定性 .结果表明 ,锌组元的引入减少了HZSM 5表面的B酸 ,增加了L酸 ,总酸量增大 ;正己烷转化率随锌含量的增加先降低后升高 ;芳烃产率和芳构化选择性则随锌含量的增加先增大后趋于平缓 ;反应过程中催化剂的积炭速度、孔体积和比表面积下降速度都随着锌含量的增加而加快 ;锌含量大于 1%时 ,Zn/HZSM 5的催化稳定性不如HZSM 5 ,且随着锌含量的增加失活速度加快 .优选的锌含量为 1 0 %～ 2 9% .此外 ,讨论了Zn/HZSM 5的催化性能与其表面性质的关系 .
The surface properties of Zn/HZSM-5 zeolite with different zinc content and its catalytic performance for n-C6H14 aromatization were studied. The results showed that, by loading zinc, the Lewis acidity and the total acidity of HZSM-5 increased, while the Bronsted acidity decreased. With the increase of zinc content, the catalytic activity and aromatization selectivity were improved. The stability of the catalyst declined when the zinc content exceeded 1%, and the more zinc on HZSM-5, the more rapid did the catalyst deactivate. The preferred zinc content in Zn/HZSM-5 is 1.0% similar to 2.9%. It is supposed that the catalytic properties of Zn/HZSM-5 is closely correlated with its surface acidity and shape-selectivity, as well as the dehydrogenation function of zinc component.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
2001年第1期57-61,共5页
