Surface reconstruction of supported Pd on LaCoO3: Consequences on the catalytic properties in the decomposition of N2O

This study deals with the catalytic decomposition of N2O over noble metal based catalysts. The deposition of palladium on reducible supports such as LaCoO3 leads to higher activity from temperature-programmed experiments in comparison with conventional supports such as alumina. Such a different catalytic behaviour cannot be completely explained by changes in the metal dispersion but also by the extent of the metal/support interaction. Interestingly, successive reductive (250 degrees C in H-2) and oxidative thermal treatments in the reactant mixture at high temperature enhance the conversion of N2O particularly on perovskite support. Additional surface characterisations show a re-dispersion and the stabilisation of palladium species in unusual oxidation states which would originate a rate enhancement in the decomposition of N2O. (C) 2007 Elsevier Inc. All rights reserved.