A Novel Amperometric Transducer Electrode with Iridium‐Niobium Binary Alloys

We have discovered that an Ir‐23Nb binary alloy more effectively oxidizes hydrogen peroxide than Ir, Ir‐13Nb, Ir‐17Nb, Ir‐30Nb, Ir‐43Nb, Ir‐62Nb, or Nb. The oxidation capability was determined via cyclic voltammogram measurements of pH‐buffer and hydrogen peroxide. We ascertained that applying a 0.7 V potential produces hydrogen peroxide currents of 9.2 μA/mm² Ir‐23Nb, 5.3 μA/mm² Ir, 5.1 μA/mm² Ir‐17Nb, 3.7 μA/mm² Ir‐13Nb, 2.0 μA/mm² Ir‐30Nb, 1.5 μA/mm² Ir‐43Nb, 0.6 μA/mm² Ir‐62Nb, and 0.13 μA/mm² Nb. These results indicate that the effective oxidation of Ir‐23Nb for hydrogen peroxide might be due to its fcc+L1₂ two‐phase structure and that Ir‐23Nb can be used as an amperometric transducer material.