Nafion Film-Templated Platinum Electrodes for Oxygen Reduction

Abstract

Nanostructured platinum electrodes were prepared by electrodeposition of platinum onto Nafion-coated gold rotating-disk electrodes (RDEs). The resultant material was characterized in acidic electrolyte by voltammetry and has been examined for electrocatalytic activity toward the oxygen reduction reaction (ORR). The platinum templated with a 3-μm Nafion film exhibited improved oxygen reduction performance in comparison to platinum-modified gold RDE prepared without templating. The mass and specific activities increased by a factor of two for the Nafion film-templated electrode, and the ORR half-wave potential (at 0.5iL) was shown to shift by 60 mV. Considering that the specific surface areas of the 3-μm Nafion film-templated and untemplated Pt were similar (14.1 vs. 11.8 m2 g−1), the enhanced kinetic performance of the former points to subtle catalyst morphology effects. The proposed method could be advantageous for the preparation of polymer electrolyte membrane fuel cell catalyst layers where the Nafion film serves also as the ionic conductor network.