Pd/TiO2 and Gd-doped Pd/TiO2 prepared through a 'one-pot' sol-gel method are shown to be active for the reduction of both N2O and NO2 using CH4 as a reducing agent under excess O-2 conditions. In previous studies these catalysts were shown to effectively reduce NO with CH4, however activity was strongly dependant on the oxidation state of Pd. Through the electropositive nature of Gd, Pd was maintained in metallic state under higher oxygen concentrations compared to the Gd-free catalysts. Characterization through XPS and in situ DRIFrS studies indicate that in the reduction of NO2, even under excess oxygen, a significant portion of the surface Pd is maintained in the active metallic state. (c) 2006 Elsevier B.V. All rights reserved.