CeO2 and Au-CeO2 thin films with different thickness were deposited on the carbon nanotubes by using magnetron sputtering of cerium dioxide and gold. The catalyst films were tested using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). XPS showed that thickness has significant influence on CeO2 films stoichiometry and in turn ceria stoichiometry influences gold oxidation states in Au doped CeO2 catalyst. (C) 2012 Elsevier B. V. All rights reserved.