Catalytic decomposition of N2O over Mg-Fe mixed oxides

A series of MgxFe1–xFe2O4 spinel oxides were prepared and characterized by means of nitrogen physisorption, X-ray diffraction (XRD) and temperature-programmed reduction of hydrogen (H2-TPR). The effect of composition, calcination temperature, and potassium doping on the catalytic activity of the Mg-Fe mixed oxides in N2O decomposition was investigated. The results indicated that the Mg0.6Fe0.4Fe2O4 catalyst calcined at 500°C exhibits highest activity in N2O decomposition. Unexpectedly, the catalyst activity is depressed by the addition of potassium, as the potassium doping may inhibit the reduction of surface iron oxides and reduce the surface area of K-modified catalysts. Long-term tests at 500°C for 10 h also illustrate that Mg0.6Fe0.4Fe2O4 is superior to FeOx catalyst either in the oxygen-alone or in the oxygen-steam concomitant atmosphere.