Pt-Cu catalysts supported on Al(2)O(3) and Nb(2)O(5) were studied for use in selective CO oxidation. The addition of copper enhanced the activity and selectivity of Pt-Cu/Nb(2)O(5) at lower temperatures when compared to Pt/Nb(2)O(5). On the other hand, copper addition was not beneficial in the case of Al(2)O(3) supported catalysts. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.