Nanosized IrO2 electrocatalysts for oxygen evolution reaction in an SPE electrolyzer

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology 2011-04, Vol.13 (4), p.1639-1646
• Main Authors: Cruz, J. C., Baglio, V., Siracusano, S., Ornelas, R., Ortiz-Frade, L., Arriaga, L. G., Antonucci, V., Aricò, A. S.
• Format: Article
• Language: English
• Subjects: Calorimetry; Characterization and Evaluation of Materials; Chemistry and Materials Science; Electrochemistry; Electrolysis; Inorganic Chemistry; Iridium; Lasers; Materials Science; Nanoparticles; Nanotechnology; Optical Devices; Optics; Photonics; Physical Chemistry; Polymers; Research Paper; X-ray diffraction
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-010-9917-2

Nanosized IrO 2 electrocatalysts ( d  ~ 7–9 nm) with specific surface area up to 100 m 2  g −1 were synthesized and characterized for the oxygen evolution reaction in a solid polymer electrolyte (SPE) electrolyzer. The catalysts were prepared by a colloidal method in aqueous solution and a subsequent thermal treatment. An iridium hydroxide hydrate precursor was obtained at ~100 °C, which was, successively, calcined at different temperatures from 200 to 500 °C. The physico-chemical characterization was carried out by X-ray diffraction (XRD), thermogravimetry–differential scanning calorimetry (TG–DSC) and transmission electron microscopy (TEM). IrO 2 catalysts were sprayed onto a Nafion 115 membrane up to a loading of 3 mg cm −2 . A Pt catalyst was used at the cathode compartment with a loading of 0.6 mg cm −2 . The electrochemical activity for water electrolysis of the membrane-electrode assemblies (MEAs) was investigated in a single cell SPE electrolyzer by steady-state polarization curves, impedance spectroscopy and chrono-amperometric measurements. A maximum current density of 1.3 A cm −2 was obtained at 1.8 V and 80 °C for the IrO 2 catalyst calcined at 400 °C for 1 h. A stable performance was recorded in single cell for this anode catalyst at 80 °C. The suitable catalytic activity and stability of the most performing catalyst were interpreted in terms of proper combination between nanostructure and suitable morphology.