A pulsed laser synthesis of nanostructured bi-layer platinum-silver catalyst for methanol-tolerant oxygen reduction reaction

In the present work, we report the synthesis by pulsed laser deposition technique of binder-free platinum layer coated with silver layer, with each layer having a thickness of about 25 nm. The resulting Pt/Ag material exhibits clear electrocatalytic activity for oxygen reduction reaction (ORR) in alkaline solution. More interestingly, it shows no activity for methanol oxidation reaction (MOR), in contrast to Pt. Furthermore, the Pt/Ag catalyst demonstrates selective activity for ORR even in the presence of concentration of methanol as high as 5 M. Such high methanol tolerance indicates good perspectives for the application of Pt/Ag catalysts in alcohol fuel cell cathodes. For portable electronic applications, the binder-free structure of the Pt/Ag catalyst with its planar deposition make it very attractive as a cathode for membrane-type DMFCs or for membraneless fuel cells such as mixed reactant microfluidic fuel cell that depends on the characteristics of the electrodes to separate the oxidation and reduction reactions.