Kinetic Modeling of the Metal/Support Interaction for CH4 Reaction over Oxidized Pd/Al2O3
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This paper deals with the kinetics of CH4 dissociation on model Pd/Al2O3 catalysts. The adsorption and conversion of CH4 over oxidized catalysts, fresh or aged, were studied with a temporal analysis of products (TAP) reactor. Single CH4 pulse TAP experiments were performed on a stabilized surface. The experiments are discussed in the light of a selected mechanism involving CH4 decomposition into CO2 taking into account an interaction between the metallic active sites and the support. TAP experiments over the oxidized catalysts confirm the involvement of the metal/support interface, with a spill-over effect. Optimized kinetics parameters validate this interaction of OH species adsorbed on Pd sites with alumina, showing a relatively good agreement between experimental and calculated outlet gas composition. Both fresh and aged catalysts follow the chosen mechanism with the same kinetic constants at 400 °C only an alteration of the catalytic surface areas explain the loss of activity.
KeywordsTAP measurements Methane activation Palladium NGV catalysts Kinetic modelling
Chevreul institute (FR 2638), Ministère de l’Enseignement Supérieur et de la Recherche, Région Nord – Pas de Calais and FEDER are acknowledged for supporting and funding this work.
- 1.EU Project - BRPR960213 (1999) Use of natural gas in passenger cars - components for bifuel vehicles and concepts to handle varying gas compositionsGoogle Scholar