Isotopic Oxygen Exchange Study to Unravel Noble Metal Oxide/Support Interactions: The Case of RuO2 and IrO2 Nanoparticles Supported on CeO2, TiO2 and YSZ

Abstract

AbstractThe aim of this study is to unravel the mechanism of (noble metal oxide)/(active support) interactions for catalytic purposes. Hence, isotopic oxygen exchange (IOE) tests were performed on Iridium‐ and ruthenium‐based oxides supported on cerium oxide (CeO2), titanium oxide (TiO2), and yttria‐stabilized zirconia (YSZ). IOE tests demonstrated the metal oxide support involvement in the propane oxidation reaction, with YSZ‐based catalysts showing the highest exchange rate of oxygen, while CeO2 and TiO2‐based catalysts had a less diffusion of lattice oxygen in that order. This is related to the presence of extrinsic oxygen vacancies in the YSZ‐based catalysts and the reduction ability of the CeO2 and TiO2 supports. Despite the limitations on oxygen exchange in some of the noble/metal oxide catalysts, their catalytic performance was comparable to the ones that showed a high oxygen exchange. Therefore, active supports results in a higher engagement of oxygen from the support but not in a linear correlation with the catalytic performance of the metal/support.