Role of lattice oxygen in the propane combustion over YSZ-supported nanoparticles and films of Pt
Résumé
Metal-Support Interactions (MSI) refers to the effect of the support on the catalytic properties of the supported metal. The phenomenon of Electrochemical Promotion of Catalysis (EPOC) deals with the modification of catalytic activity and selectivity of a catalyst film deposited on a solid electrolyte (ionic conductor) via the application of small electrical potentials or currents. Recent studies on metal-supported catalyst on TiO2 or Yttria-Stabilized Zirconia (YSZ) showed that these two phenomena can be associated with the migration of ionic promoting species containing in the support onto the metallic active sites. These species are responsible for the formation of an effective double layer at the metal-gas interface which affects the binding strength of adsorbed reactants and reaction intermediates. This study reports isotopical labelling experiments during propane oxidation on two different catalytic systems: (a) nanodispersed Pt nanoparticles supported either on ionic conductors (YSZ) or on non-conductive ceramics (ZrO2, SiO2) showing high metallic dispersion and area of triple phase boundary (TPB), (b) Pt catalyst-film deposited on a YSZ membrane (electrochemical catalyst) presenting rather low TPB surface .