fig9

Figure 9. (A) Time-dependent current behavior during Ir deposition on Au/CP using repetitive potential pulses in a N₂-purged solution of 3 mM K₃IrCl₆ and 500 mM Na₂SO₄ (pH = 4.0) at 70 °C. (B) Au 4f and Ir 4f spectra from Au/CP, Ir/Au/CP, and commercial Ir foil samples. (C) Ir 4f_7/2 peak binding energy and [Ir³⁺ + Ir⁴⁺ + Ir ^{> 4+}] area ratio of #Ir/Au/CP depending on Ir coverage. (D) LSV curves for OER activity of each electrode. (E) Tafel plots corresponding to (D). (F) CV curves of Ir-based electrodes recorded at 10 mV s^-1 in N₂-purged 0.5 M H₂SO₄. (G) Specific activity as a function of the Ir³⁺/(Ir³⁺ + Ir⁴⁺) ratio. (H) Results of OER stability testing at 10 mA cm^-2 for 8 h. (I) Polarization curve for PEMWE single cells with 30Ir/Au/CP anodes and cell voltages from literature. (J) Mass activity comparison at 1.90 V_cell depending on Ir mass loading for different Ir-based catalysts. (K) Overpotential subdivisions of (I). This figure is quoted with permission from Kim et al.^[51].