Portal de Periódicos da CAPES

The Active Phase of Palladium during Methane Oxidation

2012; American Chemical Society; Volume: 3; Issue: 6 Linguagem: Inglês

10.1021/jz300069s

1948-7185

Anders Hellman, Andrea Resta, Natalia M. Martin, Johan Gustafson, Adriana Trinchero, Per‐Anders Carlsson, Olivier Balmès, Roberto Felici, Richard M. van Rijn, J.W.M. Frenken, J. N. Andersen, Edvin Lundgren, Henrik Grönbeck,

Advanced Chemical Physics Studies

The active phase of Pd during methane oxidation is a long-standing puzzle, which, if solved, could provide routes for design of improved catalysts. Here, density functional theory and in situ surface X-ray diffraction are used to identify and characterize atomic sites yielding high methane conversion. Calculations are performed for methane dissociation over a range of Pd and PdOx surfaces and reveal facile dissociation on either under-coordinated Pd sites in PdO(101) or metallic surfaces. The experiments show unambiguously that high methane conversion requires sufficiently thick PdO(101) films or metallic Pd, in full agreement with the calculations. The established link between high activity and atomic structure enables rational design of improved catalysts.