Catalytic adsorption of SO2 on activated carbon materials provides an appropriate alternative for the control of low concentration emissions of this air pollutant. The surface complexes formed upon SO2 adsorption at 30 °C were studied by X-ray photoelectron spectroscopy (XPS) and temperature-programmed desorption (TPD). The effect of the addition of O2 and the presence of copper as catalyst were studied. Copper assisted the oxygen transfer to the carbon matrix. For the Cu-impregnated carbon sample, the presence of O2 favored SO2 adsorption by increasing the breakthrough time, the adsorption capacity and the formation of sulfur and oxygen complexes of higher thermal stabilities, which mainly desorb as SO2 and CO2.