The role of the NO adsorption and transformation over a model Pt(1%)/A1O3 catalyst for the reduction of NO by propene/O2 is discussed on the basis of NO thermodesorption and transient reactivity data. The experimental results indicate that NO strongly chemisorbs over the Pt oxidized surface and this inhibits the Pt reactivity towards hydrocarbon oxidation, but the NO then progressively migrates over the alumina surface from which it can desorb in the form of NO2. At the temperature of maximum activity in NO reduction, the rate of migration is slow and thus the hydrocarbon reacts with the adsorbed nitrogen oxide species over the metal surface, whereas at higher temperature the rate of migration is faster leaving the oxidized metal surface free for hydrocarbon combustion.
Dynamics of NO adsorption and transformation over supported Pt catalysts for the treatment of lean burn engine emissions
CENTI, Gabriele;
1999-01-01
Abstract
The role of the NO adsorption and transformation over a model Pt(1%)/A1O3 catalyst for the reduction of NO by propene/O2 is discussed on the basis of NO thermodesorption and transient reactivity data. The experimental results indicate that NO strongly chemisorbs over the Pt oxidized surface and this inhibits the Pt reactivity towards hydrocarbon oxidation, but the NO then progressively migrates over the alumina surface from which it can desorb in the form of NO2. At the temperature of maximum activity in NO reduction, the rate of migration is slow and thus the hydrocarbon reacts with the adsorbed nitrogen oxide species over the metal surface, whereas at higher temperature the rate of migration is faster leaving the oxidized metal surface free for hydrocarbon combustion.Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
