Abstract. The adsorption and oxidation of NO over GP and GOs experiment was performed in a fixed bed double tube type reactor. The experimental data showed the GOs added can enhance the adsorption and oxidation. The further DFT calculations found that the adsorption energy of NO2 is greater about 4 times than NO. The adsorption distance are with the trend of oxidation degree increase order GP < HOGP < OGP, but the adsorption energy of HOGP is bigger than OGP. The charge transfer show the NO's role changed from an acceptor on the GP surface to a donor on the OGP surface. It indicates increasing levels of covalency.