Reduction of NO with CO on CuO or Fe2O3 catalysts supported on TiO2 in the presence of O2, SO2 and water steam

The activity for the reduction of NO with CO, selectivity to N2 and the catalytic stability in the presence of O2, water steam and SO2 of Cu(II) or Fe(III) oxide catalysts supported on titania were studied. Data from XRD, H2-TPR, CO-TPR and UVVISDRS evidenced the presence of well distributed octahedral Cu(II) and Fe(III) species in the studied xCu/Ti and xFe/Ti catalysts. TG/ATD results and Rietveld refinement of the XRD pattern of the 10Cu/Ti catalyst corroborated that, during calcination, copper oxide promotes the anatase transition to rutile, leading to a higher decrease in its specific surface area when compared to the 10Fe/Ti catalyst. Despite the high interaction between Fe(III) oxide and titania, verified from the H2-TPR and CO-TPR profiles, Fe2O3 catalysts were more active and selective to N2 at temperatures lower than 450 °C than those based on CuO. Moreover, the iron (III) catalyst also showed higher stability in the presence of O2, SO2 and water steam at 500 °C. These results make Fe2O3 catalysts supported on TiO2 highly promising to be applied to the abatement of NOx emissions generated in combustion processes.