RRDE study of oxygen reduction on Pt nanoparticles inside Nafion (R): H2O2production in PEMFC cathode conditions

Dihydrogen peroxide production on platinum particles supported on carbon in side a proton exchange membrane (Nafion(R)), that is, under the working con ditions of PEMFC cathodes, is rather small at the usual oxygen reduction po tentials. As on bulk platinum, a four-electron mechanism appears to be the main pathway, with particle size and carbon substrate effects on the H2O2 p roduction. A large increase in the H2O2 contribution takes place at low pot entials, that is, at the working potentials of PEMFC anodes.