La0.8Ba0.2MnO3 and silver promoted La0.8Ba0.2MnO3 type perovskite catalysts have been studied for N2O decomposition reaction. These catalysts were prepared by co-precipitation process followed by impregnation method for Ag incorporation. These catalysts were characterized in detail by means of ICP-OES, XRD, BET, SEM, STEM, EDX, XPS, O-2-TPD and H-2-TPR analysis. An appreciable increase in catalytic activity was achieved by promoting the lanthanum manganate by Ba as well as Ag. The promotional effect of Ag was observed maximum at 1 wt% optimized loading. The effect of O-2, NO and H2O on the bare and Ag promoted catalysts for N2O decomposition was also investigated. The catalytic activity for N2O decomposition was significantly increased by Ba substitution as well as by Ag promotion. The activity of these improved catalysts was also relatively less affected in presence of oxygen, water vapour and NO, thereby showing promotional effect of silver on N2O decomposition. These catalysts were also prepared in supported forms using ceramic honeycomb via in situ co-precipitation method, and then tested for N2O decomposition reaction. Supported catalysts show equally good catalytic activity towards N2O decomposition. XPS and O-2-TPD studies suggest that Ag incorporation results in increase of Mn4+/Mn3+ ratio of La0.8Ba0.2MnO3 catalyst. TPR studies also provided the clear evidence to this effect. This improved redox property of Ag promoted perovskite catalyst was correlated to its enhanced catalytic activity for N2O decomposition. (C) 2011 Elsevier B.V. All rights reserved.