کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9636447 | 465855 | 2005 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Production of supported asymmetric catalysts in a fluidised bed
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Production of supported asymmetric catalysts in a fluidised bed Production of supported asymmetric catalysts in a fluidised bed](/preview/png/9636447.png)
چکیده انگلیسی
The production of supported catalysts by impregnation method of porous supports can be carried out in a fluidized bed. This technique allows to obtain, in only one apparatus, catalysts which by the traditional way must successively undergo the stages of impregnation, filtration, drying and calcination/activation. This paper deals with the results of experiments related to the manufacture of traditional catalysts and new generation catalysts containing various metals (nickel, manganese, copper, palladium) deposited on a porous support such as alumina or silica gel. Moreover, it was shown that the reproducible synthesis of metallic nanoparticles of size, composition and controlled surface quality could be carried out under mild conditions with organometallic precursors. The principle of this technique consists in the spraying of a solution containing a metallic precursor into a hot fluidised bed of porous fine particles as chosen support. The adequate choice of operating conditions makes possible a uniform deposit of the metal precursor inside the porous matrix. After the impregnation step, the decomposition of the metallic precursor and metal activation can be operated in the same reactor. For organometallic complexes the decomposition/activation is achieved at low temperature (T < 80 °C) under a reactive atmosphere (H2/N2 mixture) giving then rise to the synthesis of metal nanoparticles with controlled size and composition. Feasibility studies and optimisation of the operating conditions have been carried out, solid characterization and catalytic tests have been conducted to validate the process. In the case of asymmetric catalysts, Pd nanoparticles associated to cinchonidine as an asymmetric ligand inside silica particles have been prepared by this process for the ethyl pyruvate hydrogenation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Powder Technology - Volume 157, Issues 1â3, 29 September 2005, Pages 12-19
Journal: Powder Technology - Volume 157, Issues 1â3, 29 September 2005, Pages 12-19
نویسندگان
S. Desportes, D. Steinmetz, M. Hémati, K. Philippot, B. Chaudret,