Table 1: Oxygen reduction reaction characteristics of the PdCo catalysts evaluated in 0.5 M H2SO4 compared with those of Pt electrode and Pd electrode.

Electrode performanceb/mA cm−2 Specific activitye/μA cm−2
Onset potentiala/V0.65 V versus Ag/AgCl0.60 V versus Ag/AgCl0.65 V versus Ag/AgCl0.60 V versus Ag/AgClTafel slope/mV decade−1Roughness factor/−Ref.

Pt electrodef0.723.5 × 10−21.1 × 10−18.42.7 × 10171c, 116d4.2[60]
Pd thin filmg0.581.0 × 10−4 h5.8 × 10−4 h3.4 × 10−2 h1.9 × 10−1 h673.1[11]
PdCo thin filmf0.662.4 × 10−22.6 × 10−11.51.6 × 1014416[60]
PdCo dendriteg0.685.7 × 10−26.2 × 10−1 h4.44.7 × 101 h4813[15]
Modified PdCo dendriteg0.711.9 × 10−11.6h1.1 × 1019.2 × 101 h5517[15]
Nanoporous PdCo thin filmf0.693.5 × 10−12.58.66.2 × 1014341[60]
Nanoporous PdCo dendriteg0.723.9 × 10−1 i1.3i290[29]

aat the current density of 1 μA cm−2 (electrochemically active surface area). bbased on the geometrical surface area. c0.7–0.75 V. d0.55–0.65 V. ebased on the electrochemically active surface area. fmeasured by hydrodynamic voltammetry at room temperature (22°C). gmeasured by linear sweep voltammetry at (30°C). hestimated by extrapolating the Tafel slope. iwith a slight mass-transfer limitation.