Development of Electrodeposited IrO2 Electrodes and Its Catalytic Activity towards Oxygen Evolution Reaction in Polymer Electrolyte Membrane Based Water Electrolysis
By anodic electrodeposition technique, IrO2 was electrodeposited on carbon papers in a three electrode cell (Autolab, PGSTAT302N). A glassy carbon electrode and SCE were utilized as counter and reference electrodes, respectively. The deposition voltage and time were varied to control the loading amount and surface morphology. After electrodepositon, the microstructures and oxidation states of IrO2 deposition were analyzed by field emission scanning electron microscope (FE-SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The amount of deposited IrO2, which was determined by the inductively coupled plasma-mass spectrometry (ICP-MS), was 0.007~0.464 mg/cm2 at various deposition voltages and times.
For single cell tests, cathode electrodes were fabricated by spraying commercial Pt/C (Tanaka, 45.9 wt%) on carbon paper (Pt loading: 0.8 mg/cm2), and commercial Nafion 212 membranes were utilized as polymer electrolytes. Then, the water electrolysis performances were evaluated at 90oC. The highest performance was observed for the electrodes with IrO2 loading of 0.09 mg/cm2. Interestingly, although the anode catalyst loading was largely decreased, the single cell performances in this study were comparable to the previous reports [3-5].
 F. Mueller-Langer, E. Tzimas, M. Kaltschmitt, S. Peteves, Int. J. Hydrogen Energy, 32, 3797, (2007).
 K. Yamanaka, Jpn. J. Appl. Phys., 28, 632, (1989).
 Shidong Song, Huamin Zhang, Xiaoping Ma, Zhigang Shao, Richard T. Baker, Baolian Yi, Int. J. Hydrogen Energy, 33, 4955, (2008).
 Jinbin Cheng, Huamin Zhang, Guobao Chena, Yining Zhanga, Electrochim. Acta, 54, 6250, (2009).