The kinetics of the reaction of NO and N2O with activated carbon, without catalyst, and impregnated with precursor salts of Mg, Mn, Ba, Pb, Cu, Ni, Fe and Co and their binary mixtures was investigated. The conversion of NO and N2O was studied (300 degrees C-900 degrees C) using a TGA apparatus and a fixed-bed reactor. The reactor effluents were analyzed using a CC/MS on line. The best synergetic effects were observed for samples doped with Ba + Pb, Ba + Fe, Ba + Cu, Ba + Mn, and Cu + Mn. Adsorption of NO and N2O (20 degrees C-100 degrees C) increased considerably in the presence of catalysts, but binary mixtures had no synergistic effects. In situ XRD was an useful tool for interpreting catalyst behavior and identifying phases during reaction conditions.