The problem of Ru dissolution from Pt-Ru catalysts during fuel cell operation: analysis and solutions

Platinum-ruthenium catalysts are widely used as anode materials in polymer electrolyte fuel cells (PEMFCs) operating with reformate gas and in direct methanol fuel cells (DMFCs). Ruthenium dissolution from the Pt-Ru anode catalyst at potentials higher than 0.5 V vs. DHE, followed by migration and deposition to the Pt cathode can give rise to a decrease of the activity of both anode and cathode catalysts and to a worsening of cell performance. A major challenge for a suitable application of Pt-Ru catalysts in PEMFC and DMFC is to improve their stability against Ru dissolution. The purpose of this paper is to provide a better knowledge of the problem of Ru dissolution from Pt-Ru catalysts and its effect on fuel cell performance. The different ways to resolve this problem are discussed.