In situ structural changes during toluene complete oxidation on supported EuCoO3 monitored with 151Eu Mössbauer spectroscopy

Ceria–zirconia supported (10 and 20 wt.% EuCoO3) versus bulk EuCoO3 perovskite were prepared via citrate decomposition at 700 °C and tested for toluene complete oxidation. SBET, XRD, XPS, H2-TPD and in situ 151Eu Mössbauer investigations were performed. Electron delocalization processes around the Eu cations are induced by the reaction, as proved via the evolution of the Mössbauer parameters. All characterization data indicate the formation of a well-dispersed EuCoO3 at the surface of Ce0.9Zr0.1O2 for the 10 wt.% loading and larger crystallite formation for 20 wt.% loading. In terms of intrinsic activity for toluene combustion, supported catalysts were more active than bulk EuCoO3. All structural changes during operation time are reversible.