Poly(ether ether ketones) (PEEKs) are sulfonated and used as a binder in the electrode for DMFC studies. The effect of sulfonated PEEK (s-PEEK) binder in the catalyst layer on the cell performance is investigated. The s-PEEK binder in the electrode is found to be more efficient in maintaining long-term stability of the cell performance than the conventional Nation binder. The cell based on electrode having s-PEEK as a binder showed a good adhesion between electrode and electrolyte (s-PEEK membrane), while the electrode based on Nation binder was delaminated from the s-PEEK membrane after supplying the fuel for a prolonged time. (c) 2006 Elsevier B.V. All rights reserved.