The investigation describes the synthesis of Pt and Pt-Ru catalysts by a new method using a HY zeolite support. The catalysts are used to study the anodic oxidation of methanol in an acidic medium to investigate their suitability for use in direct methanol fuel cells (DMFCs). The catalysts prepared in a HY zeolite support display significantly enhanced electrocatalytic activity in the order: HY < Pt/C < Pt(HY) < Pt-Ru/C < Pt-Ru(HY). The enhanced electrocatalytic activity is explained on the basis of the formation of specific CO clusters in zeolite cages. (C) 2003 Elsevier B.V. All rights reserved.