The interaction of NO, N2O, CO, O-2, H-2 and N-2 with a stepped Au(3 1 0) surface has been studied using X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption (TPD). In the temperature (80-500 K) and pressure (up to 5 x 10(-6) mbar) range used, no adsorption Of O-2, H-2, CO and N-2, was observed. However, NO and N2O adsorb on this stepped surface. Decomposition of NO to N2O was observed at temperatures as low as 80 K. A possible mechanism for the formation of N2O from NO has been discussed on the basis of our TPXPS results. (c) 2005 Elsevier B.V. All rights reserved.