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Catalytic partial oxidation of methane on platinum investigated by spatial reactor profiles, spatially resolved spectroscopy, and microkinetic modeling
Publikationstyp
Journal Article
Date Issued
2013
Sprache
English
Author(s)
Goldsmith, Claude Franklin
Weinberg, Gisela
Kandemir, Timur
Journal
Volume
297
Start Page
1
End Page
16
Citation
Journal of Catalysis 297: (2013)
Publisher DOI
Scopus ID
ISSN
00219517
Spatially resolved profile measurements, Raman spectroscopy, electron microscopy, and microkinetic modeling have been used to study the catalytic partial oxidation of methane on Pt. The measured species profiles through Pt coated foam catalysts exhibit a two-zone structure: an abrupt change in reaction rates separates the fast exothermic oxidation chemistry at the entrance of the reactor from the slow endothermic reforming chemistry. Spatially resolved Raman spectroscopy and electron microscopy confirm that the position of the mechanistic change could be correlated with Pt transportation and formation of carbonaceous deposits blocking the majority of active Pt sites in the reforming zone. The species profiles were simulated using a pseudo-2D heterogeneous model, which includes heat and mass transport limitations, and two state-of-the-art chemical kinetic mechanisms. Although both mechanisms are in quantitative agreement with the oxygen profiles, the two mechanisms differ substantially in their predictions of the branching ratio between partial and complete oxidation, as well as surface site coverages. The experimentally observed change in reaction rates is attributed to carbon formation, which the mechanisms are unable to reproduce, since they do not include carbon-carbon coupling reactions.
Subjects
Carbon formation
Catalytic partial oxidation
Electron microscopy
Methane
Microkinetic modeling
Platinum
Raman spectroscopy
Synthesis gas