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

Elin Becker (Institutionen för kemi- och bioteknik, Teknisk ytkemi ; Kompetenscentrum katalys (KCK))
Göteborg : Chalmers University of Technology, 2010. ISBN: 978-91-7385-379-8.- 120 s.

This thesis aims at increasing the understanding of the interactions of methane and carbon monoxide with platinum in connection to catalysis and sensor technology for emission control. Specifically, the low-temperature oxidation of methane and carbon monoxide over supported platinum catalysts and the sensor response mechanism towards CO of platinum-based chemical field effect sensors were studied. Flow-reactor experiments and in situ spectroscopic methods (mainly FTIR and energy dispersive XAS) in combination with mass spectrometry were employed at both steady-state and transient reaction conditions. The results show that the support material for platinum has a considerable impact on the low-temperature activity for oxidation of both CO and methane in oxygen excess. Under such conditions methane oxidation over platinum is generally low due to oxygen-poisoning, hindering the dissociative adsorption of methane. However, by employing transient operation of the feed-gas composition, the activity for methane oxidation can be substantially increased. A new method was developed and applied for analysis of in situ XAS spectra. It was found that transient operation of the feed-gas affects the surface composition of reactants and the state of the catalyst surface. At low temperatures, the CO oxidation reaction often suffers from self-poisoning by carbon monoxide. By supplying oxygen to the reaction through alternative routes, e.g. via additional compounds or via the support material, the low-temperature activity for CO oxidation can be significantly increased. Further, the CO coverage and the reduction of oxygen from the surface of platinum-based field effect sensors were found to be important factors in the sensing mechanism towards carbon monoxide of such devices.

Nyckelord: Environmental catalysis, Low-temperature activity, Support material, Pt, CH4, CO, Periodic operation In situ spectroscopy; XAS, XANES, Chemical sensors, Sensing mechanism

Denna post skapades 2010-03-25. Senast ändrad 2013-09-25.
CPL Pubid: 118405


Institutioner (Chalmers)

Institutionen för kemi- och bioteknik, Teknisk ytkemi (2005-2014)
Kompetenscentrum katalys (KCK)


Annan kemiteknik

Chalmers infrastruktur

Relaterade publikationer

Inkluderade delarbeten:

Low-temperature activity for CO oxidation over diesel oxidation catalysts studied by high-throughput screening and DRIFT spectroscopy

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

Methane oxidation over alumina and ceria supported platinum


Datum: 2010-04-23
Tid: 10:15
Lokal: KC
Opponent: James J. Spivey

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