Direct catalytic decomposition of N2O in inert and oxidative atmosphere was investigated over two series of binary oxide catalysts containing CuO coupled with Ga2O3 or SnO2 dispersed over a silica-alumina support (CuGa/SA and CuSn/SA series catalysts). The activity for N2O decomposition in the absence of oxygen was between 0.1 and 0.2 μmol gcat s−1 in the 500–600 °C interval over the CuSn/SA series catalysts with conversion between 80 and 90%. Lower activities with larger differences were observed within the CuGa/SA series catalysts. The presence of oxygen in the feed (O2/N2O ratio up to 20:1) did not affect the activity of the CuGa/SA series while a light decrease of activity could be noticed on the CuSn/SA series. The effect of methane reductant in the selective N2O reduction (N2O-SCR) was tested. On the CuGa/SA series samples, the best reaction selectivity was observed.