ChemInform Abstract: Periodic Density Functional Theory Study of the Dissociative Adsorption of Molecular Oxygen over La2O3

Autor:	Michael M. Olken, Michael S. Palmer, Matthew Neurock
Rok vydání:	2010
Předmět:	Chemistry Oxide General Medicine Diatomic molecule Peroxide Endothermic process Dissociation (psychology) Catalysis Bond length chemistry.chemical_compound medicine Physical chemistry Oxidative coupling of methane medicine.symptom
Zdroj:	ChemInform. 33
ISSN:	1522-2667 0931-7597
DOI:	10.1002/chin.200239002
Popis:	Results of spin-polarized, gradient-corrected, periodic density functional theory calculations are reported for the dissociative adsorption of molecular oxygen over the oxide surface of La2O3(001). The diatomic surface oxygen species formed from O2 dissociation are characterized structurally by a bent orientation with respect to the surface and an OsurfaceO bond length of 1.47 A; both attributes are consistent with structural features characteristic of classical peroxides. The overall reaction energy for O2 dissociation into surface peroxide species was calculated to be endothermic by only 12.1 kcal/mol. Several reaction pathways leading to the product were examined; the lowest energy path identified involves a three-center transition state and has an apparent activation barrier of 33.0 kcal/mol. We comment on the role that peroxide species may play in the CH bond activation step of catalytic oxidative coupling of methane.
Databáze:	OpenAIRE
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