کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5362544 1388289 2009 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Assessment of surface acidity in mesoporous materials containing aluminum and titanium
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Assessment of surface acidity in mesoporous materials containing aluminum and titanium
چکیده انگلیسی
The surface acidity of mesoporous molecular sieves of aluminum and titanium was evaluated using four different techniques: n-butylamine volumetry, cyclohexylamine thermodesorption, temperature-programmed desorption of ammonia and adsorption of pyridine. The nature, strength and concentration of the acid sites were determined and correlated to the results of a probe reaction of anthracene oxidation to 9,10-anthraquinone (in liquid phase). In general, the surface acidity was highly influenced by the nature, location and coordination of the metal species (Al and Ti) in the mesoporous samples. Moderate to strong Brönsted acid sites were identified for the Al-MCM-41 sample in a large temperature range. For mesoporous materials containing Ti, the acidity was represented by a combination of weak to moderate Brönsted and Lewis acid sites. The Ti-HMS sample exhibits a higher acidity of moderate strength together with a well-balanced concentration of Brönsted and Lewis acid sites, which enhanced both conversion and selectivity in the oxidation reaction of anthracene.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 255, Issue 12, 1 April 2009, Pages 6205-6209
نویسندگان
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