کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
41109 45877 2012 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Alkylation of 3-methylthiophene by 2-methyl-1-pentene over HY, HBEA and HMCM-22 acidic zeolites
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Alkylation of 3-methylthiophene by 2-methyl-1-pentene over HY, HBEA and HMCM-22 acidic zeolites
چکیده انگلیسی

The alkylation of 3-methylthiophene with 2-methyl-1-pentene was investigated over acidic zeolites at 85 °C under atmospheric pressure in a fixed bed reactor. Three zeolites were tested, HY, HBEA and HMCM-22, which presented different pore systems but the same Brønsted acidity. Over these zeolites, 3-methylthiophene was only transformed by alkylation whereas 2-methyl-1-pentene underwent isomerization, alkylation and dimerization. No effect of the zeolite pore architecture on the initial activity was noted, but differences in stability and selectivity were observed. Indeed, HBEA was the most stable whereas HMCM-22 was the most selective in alkylation compared to olefin dimerization. The addition of toluene led to a decrease of the initial activity and the stability for all zeolites, due to competitive adsorption and coke formation. An Eley–Rideal mechanism was proposed for the alkylation reaction, where the thiophenic molecule reacts with the protonated olefin. The product distribution obtained experimentally was explained on the basis of the calculated B3LYP/cc-pVDZ stabilities of the intermediate carbocations involved in the steps proposed as rate determining.

Figure optionsDownload high-quality image (222 K)Download as PowerPoint slideHighlights
► HBEA the most stable in alkylation of 3-methylthiophene with 2-methyl-1-pentene.
► HMCM-22 the most selective in alkylation compared to olefin dimerization.
► Alkylation by an Eley–Rideal mechanism.
► Stabilities of the intermediate carbocations.
► Inhibiting effect of toluene.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Catalysis A: General - Volumes 413–414, 31 January 2012, Pages 192–204
نویسندگان
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