کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9608085 | 46036 | 2005 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Catalytic activity of micro/mesoporous composites in toluene alkylation with propylene
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
کاتالیزور
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Catalytic activity of micro/mesoporous composites in toluene alkylation with propylene Catalytic activity of micro/mesoporous composites in toluene alkylation with propylene](/preview/png/9608085.png)
چکیده انگلیسی
The gas phase alkylation of toluene with propylene was used to investigate the catalytic activity of pure zeolite Beta, pure mesoporous molecular sieve Al-MCM-41 and micro/mesoporous composites. The influence of the structural features and the concentration of acid sites of these catalysts on the toluene conversion and the selectivity to isopropyltoluenes (cymenes) was studied. Various characterization techniques, i.e., DLS, SEM, XRD, FT-IR, NMR, and nitrogen sorption measurements were applied for complete characterization of the catalysts. In addition, the concentrations of Brönsted and Lewis acid sites were determined based on the amount of adsorbed d3-acetonitrile using FT-IR spectroscopy. The catalytic activity in toluene alkylation with propylene was increased in the order: Al-MCM-41 < micro/mesoporous composites < commercial zeolites Beta < nanosized zeolite Beta. This sequence clearly shows the role of strong Brönsted acid sites in the reaction together with the decrease in the transport limitations with decreasing size of zeolite crystals. The enhancement of toluene conversion over micro/mesoporous composites compared to Al-MCM-41 is due to the presence of zeolite particles in composite catalyst increasing the acidity of this material.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Catalysis A: General - Volume 281, Issues 1â2, 18 March 2005, Pages 85-91
Journal: Applied Catalysis A: General - Volume 281, Issues 1â2, 18 March 2005, Pages 85-91
نویسندگان
Pavla ProkeÅ¡ová, NadÄžda Žilková, Svetlana Mintova, Thomas Bein, JiÅà Äejka,