کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
58342 47147 2007 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Investigation of co-hosted basic and metal nanoparticles in Pt/Cs-BEA zeolites
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی کاتالیزور
پیش نمایش صفحه اول مقاله
Investigation of co-hosted basic and metal nanoparticles in Pt/Cs-BEA zeolites
چکیده انگلیسی

Various acido-basic BEA zeolites having different Cs contents and containing supported Pt particles were prepared using two acidic parent BEA supports with same framework Al content but with strongly different morphology of the zeolite crystallites. In spite of highly different exchange capacities in aqueous solution, the two parent BEA supports behaved similarly towards formation of Cs-oxide like nanospecies. Thus, the addition of a similar amount of Cs was necessary in the two samples to extinguish all Brønsted acidic sites and a further introduction of Cs led to the presence of highly dispersed Cs2O like species with strong basic character as shown by the adsorption of CO2 followed at 293 K by FT-IR spectroscopy. FT-IR experiments were also conducted at 100 K and 293 K using CO as probe molecule to give further insights on the Cs and reduced Pt species, respectively. In the presence of co-hosted Cs-oxide like, highly dispersed Pt0 nanoparticles are formed with sizes close to 1 nm as observed by TEM. Both the high dispersion of the Pt0 nanoparticles in the more basic samples and the phenomenon of electro-donation by the basic support contribute to the changes in electronic behaviour of the Pt0 particles shown by FT-IR of adsorbed CO.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Catalysis Today - Volume 124, Issues 1–2, 15 June 2007, Pages 36–42
نویسندگان
, , , ,