Oxidation of methane on nanoparticulate Au/TiO2 at low temperature: A combined microreactor and DFT study

Herein we present results from experimental and theoretical studies concerning low temperature oxidation of CH4 over TiO2 supported Au nanoparticles. Our findings suggest that partial oxidation cannot be achieved under these conditions (1 bar, 30-250 degrees C). In order to understand this further, results from CO and H-2 oxidation studies are also presented. The reaction rate for CH4 oxidation is found to be far lower than the rate for both CO and H-2 oxidation, this goes towards explaining the strong tendency for total CH4 oxidation. These findings are further corroborated by DFT-calculations investigating the thermodynamics of CH4 oxidation on a stepped Au(2 1 1) surface. (C) 2009 Elsevier B.V. All rights reserved.