| Autor: |
E. Loukine, Christelle Alié, Benoît Heinrichs, Fabrice Ferauche, Pierre Marchot, Jean-Paul Pirard, Stéphanie Lambert, Angélique Léonard, Michel Crine, Natalia Tcherkassova |
| Rok vydání: |
2006 |
| Předmět: |
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| Zdroj: |
Chemical Engineering Journal. 117:13-22 |
| ISSN: |
1385-8947 |
| Popis: |
A Pd-Ag/SiO 2 xerogel catalyst prepared in one step by sol-gel p rocess has been entrapped in cylindrical porous alumina foams of three different pore sizes in orde r to shape the catalyst under the appropriate form with suitable mechanical resistance to be used in an industrial f ixed bed reactor. After drying, calcination and red uction, the Pd-Ag/SiO 2 xerogel catalyst pellets are immobilized inside th e open porosity of the alumina foam. The localization of the xerogel catalyst in the alumina foams has been studied by X-ray tomography. The threedimensional porous structure was reconstructed from the consecutive cross-sections obtained by this te chnique. This method shows that the Pd-Ag/SiO 2 xerogel catalyst is uniformly dispersed inside the porosity of the alumina foams. Activity and selectivity of Pd-Ag/Si O 2 xerogel catalyst reference or catalyst entrapped i n alumina foams have been studied for selective hydro dechlorination of 1,2-dichloroethane into ethylene. The specific reaction rate obtained with catalyst entra pped in alumina foams is smaller than the one obtai ned from corresponding catalyst powders. The catalytic activ ity decrease observed for Pd-Ag/SiO 2 xerogel catalyst entrapped in porous alumina foams most probably arises from diffusional limitations inside the porous texture of the alumina foams. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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