In-situ XPS investigation of nitric oxide adsorption on (111), (310), and (533) gold single crystal faces

Decomposition of nitric oxide on the flat (111) and stepped (310) and (533) faces of gold single crystals was investigated by in-situ X-Ray Photoelectron Spectroscopy at elevated NO pressures up to 7Pa and temperatures between 300K and 500K. The adsorbed layer formed on the gold surfaces at these conditions was found to contain nitrogen adsorbed atomically and/or nitrous oxide. The population of these adspecies was found to be dependent upon the crystal structure of the Au face, as well as the sample temperature and NO pressure. Explanations for these phenomena are discussed. ► Decomposition of NO at flat Au(111), stepped Au(310) and Au(533). ► Nads is the exclusive product of NO adsorption on Au(310). ► Additional surface species, N2Oads, is produced when NO adsorbs on Au(533). ► Geometric factor is a reason for high activity of gold catalyst in NO reduction.