In Situ Spectroscopic Investigation of Low-Temperature Oxidation of Methane over Alumina-Supported Platinum during Periodic Operation
Artikel i vetenskaplig tidskrift, 2011

Methane oxidation over Pt/Al2O3 at transient inlet-gas conditions was studied in situ using synchronous energy dispersive X-ray absorption spectroscopy, Fourier transform infrared spectroscopy, and mass spectrometry. The employed combination of experimental techniques allows for simultaneous analysis of the electronic state of platinum, surface coverage of reaction intermediates/products, and catalytic activity/selectivity, respectively. By cycling of the feed gas composition between net-oxidizing and net-reducing conditions, the activity for methane oxidation can be increased as compared to continuous net-oxidizing conditions. Using the white-line area of time-resolved X-ray absorption near-edge structure spectra, a quantitative estimation of the surface O/Pt ratio indicates the formation of an inhomogeneous surface oxide on the platinum crystallites during reaction. The obtained temporary high activity can be explained through Langmuir-Hinshelwood kinetics and may result either from the formation of a partially oxidized platinum surface that is more effective for methane dissociation or, more likely, from a period with more reactive chemisorbed oxygen prior to oxide formation.

Författare

Elin Becker

Kompetenscentrum katalys (KCK)

Chalmers, Kemi- och bioteknik, Teknisk ytkemi

Per-Anders Carlsson

Kompetenscentrum katalys (KCK)

Chalmers, Kemi- och bioteknik, Teknisk ytkemi

Lisa Kylhammar

Chalmers, Kemi- och bioteknik, Teknisk ytkemi

Mark A Newton

European Synchrotron Radiation Facility (ESRF)

Magnus Skoglundh

Kompetenscentrum katalys (KCK)

Chalmers, Kemi- och bioteknik, Teknisk ytkemi

Journal of Physical Chemistry C

1932-7447 (ISSN) 1932-7455 (eISSN)

Vol. 115 4 944-951

Drivkrafter

Hållbar utveckling

Styrkeområden

Nanovetenskap och nanoteknik

Transport

Energi

Materialvetenskap

Ämneskategorier

Fysikalisk kemi

Kemiska processer

DOI

10.1021/jp103609n

Mer information

Skapat

2017-10-07