Abstract: In a process for redispersion of the iridium agglomerates (irridium and/or iridium oxide) of a deactivated iridium-containing catalyst, especially a platinum-iridium catalyst, in ferrous metal equipment, wherein the agglomerated iridium, or agglomerated platinum and iridium, is redispersed and the catalyst reactivated by sequential prereduction-halogen treatments, the improvement comprising adding and maintaining small amounts of water with the halogen to suppress ferrous metal corrosion and catalyst contamination during the required treatment with halogen.