In addition to zeolites, Metal-porphyrins is of interest for using as catalysts for O2 and CO adsorption processes. Recently, by using DFT calculation we have suggested Ti-porphyrins as a potential catalyst for N2O decomposition.10 We found that Ti atom was reactive to not only N2O gas, but it also can react with NO, and CO2 as well. Therefore, it is possible that metal-porphyrins might be potential catalysts for NO decomposition.