Abstract Oxygen Reduction Reaction (ORR) currents have been measured under the
potential range of an operating fuel cell (0.72–0.9 Volts) while keeping proton and oxygen
transport-related overpotentials insignificant by testing with pure O 2, at 100% RH and at low
current densities. Low potential points are achieved by reducing the platinum loading on the
cathode and operating under sub-ambient (< 101.3 kPa abs) pressure. The resulting
experimental data are fit to Pt-oxide-coverage-dependent kinetics and the kinetic …

Oxygen Reduction Reaction (ORR) currents have been measured under the potential range
of an operating fuel cell (0.72-0.9 Volts) while keeping proton and oxygen transport-related
overpotentials insignificant by testing with pure O2, at 100% RH and at low current densities.
Low potential points are achieved by reducing the platinum loading on the cathode and
operating under subambient (< 101.3 kPaabs) pressure. The resulting experimental data are
fit to Pt-oxide-coverage-dependent kinetics and the kinetic parameters extracted.