کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
75864 49125 2010 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Modification of MOR by desilication treatments: Structural, textural and acidic characterization
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Modification of MOR by desilication treatments: Structural, textural and acidic characterization
چکیده انگلیسی

The effect of several desilication experimental parameters (base concentration, temperature and time) on the characteristics of MOR zeolite was studied. The samples were characterized by X-ray diffraction, 27Al and 29Si MAS-NMR, chemical analysis, and FTIR (framework vibration region). The textural characterization was made by N2 adsorption and the acidity was evaluated by pyridine adsorption followed by FTIR and by the catalytic model reaction of n-heptane cracking. The alkaline treatments promoted the Si extraction from the zeolite framework, without considerable loss of crystallinity and, as it was envisaged, an important increase of the mesoporous structure was attained. A linear correlation between the number of framework Si per unit cell, NSi, and the asymmetric stretching wavenumber, ν1, was observed. The acidity characterization shows that the desilicated samples exhibit practically the same acid properties than the parent HMOR zeolite. The optimum desilication conditions were those used to obtain sample M/0.2/85/2, i.e., sample treated with 0.2 M NaOH solution at 85 °C for 2 h.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Microporous and Mesoporous Materials - Volume 131, Issues 1–3, June 2010, Pages 350–357
نویسندگان
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