Simultaneous adsorption of NO and SO2 on activated carbon provides an adequate alternative to control the low concentration emissions of these air pollutants. The surface complexes formed during the NO and SO2 adsorptions at 30 °C were studied by X-ray photoelectron spectroscopy (XPS) and temperature-programmed desorption (TPD). The effects of the addition of copper supported on the carbon and O2 on the gas stream were studied. The presence of copper enhanced the chemical adsorption of both NO and SO2. In the simultaneous adsorption of NO and SO2, SO2 inhibited the adsorption of NO, while SO2 adsorption was notably improved. The reaction carried out under a NO/SO2/O2 gas mixture showed a synergic effect increasing the formation of surface complexes. The addition of copper assisted the oxygen transfer to the carbon matrix.