Ferric hydroxide supported Pd catalyst prepared by a simple co-precipitation method without calcinations at elevated temperatures and only reduced at 50 degrees C possessed unexpectedly higher activity for CO oxidations even compared with that of supported Au catalysts. XRD and TEM results showed that the support was mixture of Fe(OH)(x) and Fe3O4 and Pd was highly dispersed on it. XPs results showed that Pd existed as mixture of oxidation and metal state. The large amount of OH group on the supports may play an important role in O adsorption and activation. (C) 2008 Published by Elsevier Inc.