Au catalysts on different type of reducible supports (TiO2, Co3O4-CeO2 mixed oxide, CeO2, Co3O4) and over a non-reducible oxide, Al2O3, were prepared by deposition-precipitation method with Na2CO3 solution at pH 7-8, depending on the PZC of the supports. The as-prepared catalysts were characterized by BET, XRD, TEM and XPS techniques. The catalytic activity was investigated in the CO oxidation and in the preferential CO oxidation in the presence of hydrogen (PROX). The results were discussed in terms of nature of gold species and role of the support in the reaction mechanism. (C) 2010 Elsevier B.V. All rights reserved.