Density functional study on the activation of methane over Pd{sub 2}, PdO, and Pd{sub 2}O clusters

Journal Article · Wed Feb 05 04:00:00 EST 1997 · International Journal of Quantum Chemistry

DOI:https://doi.org/10.1002/(SICI)1097-461X(1997)61:4<673::AID-QUA9>3.0.CO;2-T· OSTI ID:530817

Broclawik, E ^[1]; Yamauchi, Ryo; Endou, Akira ^[2]

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1. Institute of Catalysis, Cracow (Poland)
2. Tohoku Univ., Sendai (Japan); and others

Simple functional models for elementary steps in the total oxidation of methane over supported palladium catalysts were investigated using density function theory. Three simple cluster models were proposed, namely, the palladium dimer and PdO diatomic and linear Pd{sub 2}O, to probe the mechanism of the methane activation on metallic and oxidized palladium phases, respectively. The strongest adsorption was found on Pd{sub 2}, where also the C-H bond became easily activated; however, no stable product of the C-H bond scission was indicated. Similar hydrogen activation took place on Pd{sub 2}O and, in addition, adsorbed methyl and OH species formed the most stable system after crossing a moderate energy barrier. The same product was previously found stable also in the case of PdO dimer but the activation barrier was high. On the Pd{sub 2}O cluster, the process of energy barrier crossing was accomplished in two steps: easy formation of a free hydrogen moiety and actual oxidation, which made the overall process less demanding energetically. 21 refs., 5 figs., 3 tabs.

• OSTI ID: 530817
• Report Number(s): CONF-9508188--
• Journal Information: International Journal of Quantum Chemistry, Journal Name: International Journal of Quantum Chemistry Journal Issue: 4 Vol. 61; ISSN IJQCB2; ISSN 0020-7608
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
ADSORPTION
CATALYTIC EFFECTS
FUNCTIONAL MODELS
HYDROGEN
METHANE
OXIDATION
PALLADIUM
PALLADIUM OXIDES