The catalytic adsorption of NO on activated carbon materials provides an appropriated alternative for the control of low-concentration emissions of this air pollutant. The surface complexes formed upon NO adsorption at 30 degrees C were studied by X-ray photoelectron spectroscopy (XPS) and temperature-programmed desorption (TPD). The effects of the addition Of 02 and the presence of copper as a catalyst were studied. Copper assisted the oxygen transfer to the carbon matrix. For the Cu-impregnated carbon sample, the presence of O-2 favored NO adsorption by increasing the breakthrough time, the adsorption capacity, and the formation of nitrogen and oxygen complexes of higher thermal stabilities, which mainly desorbed as NO and CO2.