Fig. 7: Comparison of catalytic durability.
Three distinct electrochemical tests based on a CP, b CV, and c CA were carried out in 1 M HClO4 with 0.5 mg/cm2 mass loading to measure the catalytic longevity of rutile IrO2 samples with two different particle sizes. The CP test in (a) shows significant size-dependent variation, revealing that much lower overpotential is required to achieve 10 mA/cm2 for the fine-particle sample and thereby far longer lifetime is attained. In contrast, analogous behavior of the current variation insensitive to the particle size is observed in the CV and CA measurements in (b, c). d, e Three materials, IrO2, 9R-BaIrO3, and 12R-Ba4NbIr3O12, were measured by the CV and CA methods, respectively. Ba4NbIr3O12 demonstrates notable durability.
