MeOx/ZrO2 (Me = Co and Fe) catalysts were studied for the simultaneous selective catalytic reduction of NO and N2O in the presence of O-2 using C3H6 as reducing agent (SCRsim). To give a better insight in the simultaneous process we investigated the reactions related to SCRsim (SCRN2O, SCRNO, N2O decomposition and C3H6 combustion) as well as the abatements in the absence of O-2 (CRsim, CRN2O, CRNO). Catalytic results showed that, in the presence of O-2 excess, CoO2/ZrO2 and FeOx/ZrO2 catalysts were scarcely active and unselective for the separate NO and N2O abatements with C3H6 and are ineffective for their simultaneous abatement. Because C3H6 preferentially reacted with O-2, NO was poorly reduced and N2O was abated, at a temperature above that of complete C3H6 conversion, via both SCR(N2O )and decomposition. Conversely, in the absence of O-2 in the feed, on both catalysts NO and N2O were efficiently reduced by C3H6, but undesired by-products formed. The activity for SCRsim strongly depended on the C3H6/O-2 feeding ratio. With suitable feeding mixture O-2 was completely consumed and the residual propene efficiently and simultaneously reduced NO and N2O, with negligible formation of by-products. In hydrothermal conditions both catalysts were slightly and reversibly deactivated. Characterization by XRD, UV-vis DRS and FTIR after catalytic experiments showed that dispersed Co2+ and Fe3+ species were stable on zirconia surface and that no significant segregation phenomena occurred in hydrothermal conditions. (C) 2017 Elsevier B.V. All rights reserved.