Relevance of the nature of bimetallic PtAu nanoparticles as electrocatalysts for the oxygen reduction reaction in the presence of methanol

A series of carbon supported PtAu electrocatalysts has been prepared. The performance of the samples in the methanol oxidation reaction and in the oxygen reduction reaction has been investigated by means of electrochemical techniques. The combined process, oxygen reduction reaction in the presence of methanol, has also been studied by electrochemical methods and in a single-cell. Irrespective of the performance of the samples in the oxygen reduction reaction, the ones displaying poor activity in the methanol oxidation reaction are the optimum cathode electrocatalysts for direct methanol fuel cell applications. The role of Au was found to be dependent on the actual nature of the catalyst. When alloyed, the role of Au on the methanol oxidation reaction is negligible. This is the first time that Au is being proposed as a component of methanol resistant cathode electrocatalysts.