The influence of the calcination temperature on the structure and catalytic activity of 2 wt% Pd/LaFeO3 for methane combustion has been investigated. LaFeO3 (calcined at 700 degrees C) was impregnated with Pd(NO3)(2) and subsequently calcined at temperatures between 300 degrees C and 1000 degrees C. Characterization using TPR, XPS, DRIFTS and XAS revealed the presence of Pd in at least two different coordination environments. A fraction of Pd2+ in PdO-like particles coexists with Pdn+. (n >2) dissolved in LaFeO3. The relative fraction of the two species appears to change depending on the calcination temperature as a result of incorporation of Pd into LaFeO3. The effect of this variation is discussed in relation to the catalytic activity. Pd/LaFeO3 calcined at 500 degrees C exhibited the best methane combustion activity during a heating-cooling cycle performed in the temperature range of 200-900 degrees C. The strong interaction between Pd and LaFeO3 renders Pd/LaFeO3 calcined at 500 degrees C stable against repeated cycles of thermal aging under the reactants atmosphere. At high temperature the relative distribution of Pd2+ and Pdn+ species and therefore catalytic activity are further affected by the occurrence of the thermal PdO <-> 44 Pd equilibrium suggested by the activity loss during the cooling segment. (C) 2011 Elsevier B.V All rights reserved.