Abstract

Two different forms of rutile-type iridium oxide catalysts were prepared: IrO 2-coated titanium plate electrocatalysts prepared by a dip-coating method (IrO 2/Ti) and iridium oxide nanoparticles (IrO 2) prepared by a wet method, the Adams fusion method. The catalytic behavior of the oxygen reduction reaction (ORR) was evaluated by cyclic voltammetry in 0.5 M H 2SO 4 at 60 °C. Both catalysts were found to exhibit considerable activity for the ORR; however, the former oxide electrodes showed higher activity than the latter ones. All the IrO 2/Ti catalyst electrodes heat-treated at a temperature between 400 °C and 550 °C showed ca. 0.84 V (vs. RHE) of the onset potential for the ORR, E ORR, where the reduction current of oxygen had begun to be observed during the cathodic potential sweep of the test electrodes. It has been confirmed clearly that IrO 2, but neither metallic Ir nor the hydrated IrO 2, behaves as an active catalyst for the ORR in an acidic solution. It was also demonstrated that the enlargement of the surface area of the IrO 2/Ti with the help of lanthanum is effective for the enhancement of the catalytic activity in the reaction.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.