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Dissociative Adsorption of Methane on Surface Oxide Structures of Pd-Pt Alloys

Autor(en)

Arezoo Dianat, Nicola Seriani, Lucio Colombi Ciacchi, Wolfgang Pompe, Gianaurelio Cuniberti, Manfred Bobeth

Abstrakt

The dissociative adsorption of methane on variously oxidized Pd, Pt, and

Pd−Pt surfaces is investigated using density functional theory as a

step toward understanding the combustion of methane on these materials.

For Pd−Pt alloys, models of surface oxide structures are built on the

basis of known oxides on Pd and Pt. The methane adsorption energy

presents large variations depending on the oxide structure and

composition. Adsorption is endothermic on the bare Pd(111) metal surface

as well as on stable thin layer oxide structures such as the (√5 × √5)

surface oxide on Pd(100) and the PtO₂-like oxide on Pt(111).

Instead, large adsorption energies are obtained for the (100) surface of

bulk PdO, for metastable mixed Pd_1−xPt_xO_4/3

oxide layers on Pt(100), and for Pd−Pt(111) surfaces covered with one

oxygen monolayer. In the latter case, we find a net thermodynamic

preference for a direct conversion of methane to methanol, which remains

adsorbed on the oxidized metal substrates via weak hydrogen-bond

interactions.

Organisation(en)

Computergestützte Materialphysik

Externe Organisation(en)

University of Cambridge, Technische Universität Dresden

Journal

The Journal of Physical Chemistry Part C (Nanomaterials and Interfaces)

Band

113

Seiten

21097-21105

Anzahl der Seiten

ISSN

1932-7447

DOI

https://doi.org/10.1021/jp905689t

Publikationsdatum

2009

Peer-reviewed

ÖFOS 2012

103009 Festkörperphysik, 103015 Kondensierte Materie, 103025 Quantenmechanik, 103036 Theoretische Physik

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