摘要
考察了水热处理对 Zn/ HZSM- 5催化剂丙烷芳构化反应的影响 ;并采用 FT- IR手段 ,研究了处理温度对催化剂表面酸性的影响 .结果表明 ,随着水热处理温度的升高 ,单位晶胞中的 B酸中心数减少 ,而 L酸中心数增加 ,丙烷的转化率和芳烃选择性升高 ,水热处理温度为 40 0℃时达到最大值 ,此时催化剂的脱氢中心 Zn2 + 与聚合、环化的 B酸中心为最佳匹配状态 .随着处理温度的进一步升高 ,B酸中心数显著下降 ,丙烷的转化率和芳烃选择性下降 .
Zn/HZSM 5 catalysts for aromatization of propane were modified by hydrothermal treatment method, and the catalyst performance was investigated. It was found that the propane conversion and aromatics selectivity increase with treatment temperature. The catalysts treated at 400 ℃ had the best performance for aromatics synthesis, the conversion of propane and selectivity to aromatics reach 81% and 73%, respectively, under the reaction conditions of 550 ℃ and 600 h -1 . FT IR results showed that Lewis acid centers increased while Brnsted acid centers decreased with the increase of treatment temperatures. However, both of them declined markedly above 500 ℃. The best B/L acid ratio for aromatics was obtained with the catalyst treated at 400 ℃.
出处
《分子催化》
EI
CAS
CSCD
北大核心
2000年第4期289-293,共5页
Journal of Molecular Catalysis(China)
