In order to protect the perfluorosulfonic acid (PFSA) ionomer from an attack of contaminant metal ions as well as to enhance the mechanical stability of catalyst layers, palygorskite (PGS) is introduced into the catalyst layer of polymer electrolyte membrane fuel cells. PGS is a widely used natural nano-sized silicate mineral fiber with unique nano-sized channel structure, has a strong absorption capacity for heavy metal ions. We identify a negative influence of Fe(2+) on PFSA membranes to make a comparative study. Subsequently catalyst coated membranes (CCMs) prepared with a PGS-Pt/C composite catalyst show a great effect in reducing Fe(2+) ion crossover. Results display that PGS absorbs Fe(2+) in nano-structure channels, and effectively protect PFSA ionomer in both the catalyst layer and membrane from hydroxyl radicals (OH(center dot)) attack. Thus, the chemical stability of PFSA ionomer in both the catalyst layer and membrane is greatly improved. Furthermore, the enhancement of the mechanical performance of catalyst layers is discussed. (C) 2011 Elsevier B.V. All rights reserved.