CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

Methane oxidation over alumina supported platinum investigated by time-resolved in situ XANES spectroscopy

Elin Becker (Institutionen för kemi- och bioteknik, Teknisk ytkemi ; Kompetenscentrum katalys (KCK)) ; Per-Anders Carlsson (Institutionen för kemi- och bioteknik ; Kompetenscentrum katalys (KCK)) ; Henrik Grönbeck (Institutionen för teknisk fysik, Kemisk fysik ; Kompetenscentrum katalys (KCK)) ; Magnus Skoglundh (Institutionen för kemi- och bioteknik ; Kompetenscentrum katalys (KCK))
Journal of Catalysis (0021-9517). Vol. 252 (2007), p. 11-17.
[Artikel, refereegranskad vetenskaplig]

In situ time-resolved X-ray absorption spectroscopy and mass spectrometry were used to correlate changes in catalyst surface composition with catalytic activity for methane oxidation over alumina supported Pt. Different transient experiments (i.e., pulsing of oxygen or hydrogen to an otherwise constant gas composition) were performed to study the methane oxidation kinetics. Changes in the surface O/Pt ratio were monitored by the introduction of a new analysis method of the white line area corresponding to the Pt L-III-edge XANES spectra. The relevance of the method was confirmed by first-principles calculations demonstrating how hydrogen and oxygen adsorbates modify the electronic structure of Pt. The experimental results show that during the gas-phase transients, the surface O/Pt ratio changes, which in turn affects the methane oxidation rate. Activity maxima are observed for an intermediate surface O/Pt ratio. An oxygen-rich surface seems to hinder the dissociative adsorption of methane, leading to low methane oxidation activity at oxygen excess.

Nyckelord: heterogeneous catalysis; transient methods; X-ray absorption spectroscopy; dissociative adsorption; platinum oxide; CH4; Pt; Pt/Al2O3



Den här publikationen ingår i följande styrkeområden:

Läs mer om Chalmers styrkeområden  

Denna post skapades 2008-01-08. Senast ändrad 2017-09-14.
CPL Pubid: 64788

 

Läs direkt!


Länk till annan sajt (kan kräva inloggning)


Institutioner (Chalmers)

Institutionen för kemi- och bioteknik, Teknisk ytkemi (2005-2014)
Kompetenscentrum katalys (KCK)
Institutionen för kemi- och bioteknik (2005-2014)
Institutionen för teknisk fysik, Kemisk fysik (1900-2015)

Ämnesområden

Energi
Materialvetenskap
Nanovetenskap och nanoteknik
Transport
Hållbar utveckling
Kinetik
Spektroskopi
Kemiteknik

Chalmers infrastruktur

Relaterade publikationer

Denna publikation ingår i:


Interactions of methane and carbon monoxide with platinum - Supported catalysts and chemical sensors


Interaction of CO and methane with platinum, Low-temperature oxidation and sensor response mechanisms