Carbon formation in catalytic partial oxidation of methane on platinum: Model studies on a polycrystalline Pt foil

A polycrystalline Pt foil has been investigated as model catalyst in methane catalytic partial oxidation to synthesis gas. It is demonstrated that a substantial amount of carbonaceous deposits forms on the Pt foil upon reaction light-off blocking a large fraction of Pt surface atoms. By using in situ Raman spectroscopy and quantitative spectral analysis the evolution and spatial distribution of these carbonaceous compounds with reaction temperature and reaction time have been characterized. The chemical composition of the carbon material changes from highly reactive and strongly disordered directly after reaction light-off to highly ordered, oxidation and steam reforming resistant after several hours time on stream at 800 °C reaction temperature. Remarkably the carbon distribution at the Pt surface was found to be inhomogeneous and related to the nature of the microcrystals forming the polycrystalline foil in a yet unknown manner.

Figure optionsDownload high-quality image (266 K)Download as PowerPoint slideHighlights
► Carbon is formed on platinum in catalytic partial oxidation of methane.
► We study carbon formation by in situ Raman spectroscopy.
► Amorphous Carbon is formed upon reaction light-off and transforms into graphitic carbon with time on stream.
► The graphitic carbon is oxidation resistant and blocks Pt atoms for catalysis.
► Carbon formation is inhomogeneous on a polycrystalline Pt foil.