کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
75092 49108 2009 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Characterisation by adsorption of various organic vapours of the porosity of fresh and coked H-MCM-22 zeolites
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Characterisation by adsorption of various organic vapours of the porosity of fresh and coked H-MCM-22 zeolites
چکیده انگلیسی

The microporosity of H-MCM-22 samples, fresh and deactivated by coke during methylcyclohexane transformation at 350 °C for 10 h, was characterised by adsorption of nitrogen and organic molecules of different size, namely, p- and o-xylenes, mesitylene and methylcyclohexane. Nitrogen adsorption was also carried out on the fresh sample after pre-adsorption of the hydrocarbons. All of these can fit the outer 12 MR cups, but show differences in their ability to enter the internal microporosity. p-Xylene can enter all the inner micropores, methylcyclohexane adsorbs in the supercages and at some sinusoidal channel entrances, o-xylene is adsorbed at the pore windows of the supercages only, and mesitylene is completely excluded from the inner micropores. It was deduced that the microporosity of the MCM-22 sample investigated consists of 0.01 cm3 g−1 of outer pockets (∼5% of the total volume), 0.06 cm3 g−1 of sinusoidal channels (∼32%) and 0.12 cm3 g−1 of supercages (∼63%). Coke deposited during methylcyclohexane transformation caused the complete blockage of the supercages but had no effect on the outer cups and sinusoidal channels.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Microporous and Mesoporous Materials - Volume 118, Issues 1–3, 1 February 2009, Pages 473–479
نویسندگان
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