title: Remarkable enhancement of O₂ activation on yttrium-stabilized zirconia surface in a dual catalyst bed.
abstract: Yttrium-stabilized zirconia (YSZ) has been extensively studied as an electrolyte material for solid oxide fuel cells (SOFC) but its performance in heterogeneous catalysis is also the object of a growing number of publications. In both applications, oxygen activation on the YSZ surface remains the step that hinders utilization at moderate temperature. It was demonstrated by oxygen isotope exchange that a dual catalyst bed system consisting of two successive LaMnO3 and YSZ beds without intimate contact drastically enhances oxygen activation on the YSZ surface at 698 K. It can be concluded that LaMnO3 activates the triplet ground-state of molecular oxygen into a low-lying singlet state, thereby facilitating the activation of the O2 molecule on the YSZ oxygen vacancy sites. This phenomenon is shown to improve the catalytic activity of the LaMnO3-Pd/YSZ system for the partial oxidation of methane.
authors.affiliation: University of Poitiers, CNRS, UMR 7285, Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), 4 rue Michel Brunet-TSA 51106-86073 Cedex 9 (France).
authors.forename: Mélissandre
authors.initials: M
authors.lastname: Richard
authors.forename: Fabien
authors.initials: F
authors.lastname: Can
authors.forename: Daniel
authors.initials: D
authors.lastname: Duprez
authors.forename: Sonia
authors.initials: S
authors.lastname: Gil
authors.forename: Anne
authors.initials: A
authors.lastname: Giroir-Fendler
authors.forename: Nicolas
authors.initials: N
authors.lastname: Bion
keywords: methane; oxidation; oxygen exchange; singlet oxygen; yttrium-stabilized zirconia