ausblenden:
Schlagwörter:
Hydrocarbons; surface spectroscopy; catalytic properties; carbon deposition;
Zusammenfassung:
Hydrocarbonaceous deposits are normally present on Pt during hydrocarbon reactions.
Carbon deposition is dehydrogenated during evacuation and appear as “graphitic”,“polymeric” and “deactivating” carbon. The latter may correspond to “disordered” carbon. C atoms on Pt can also be present.
Activity and selectivities of “skeletal” reactions of hexane (isomerization, C5-cyclization, aromatization, fragmentation) are influenced by the amount and chemical state of carbon.
This depends of the temperature of treatment and the presence of H2.