Dissolution of Ir oxides in Ir-based catalysts, which is closely linked to the catalyst activity and stability toward the oxygen evolution reaction (OER) in acidic media, is a critical unresolved problem in the commercialization of water electrolysis. Doping foreign elements into the Ir oxides can accomplish an optimal combination of Ir oxidation states that is conducive to the leaching-resistance of active catalytic sites. Here, it is reported that Pt doping into IrOx-based nanoframe is beneficial in both terms of activity and stability. The Pt-doped IrOx-based nanoframe achieves the mass activity of 0.644 A mg−1Ir+Pt at 1.53 VRHE, which is 15-fold higher than that of the commercial IrO2. During the accelerated durability test, the IrIV-to-IrIII ratio of 5 is maintained in the presence of Pt dopant to effectively mitigate the degradation of Ir catalyst, leading to the superb catalyst durability in acidic media.
Bibliographical noteFunding Information:
S.C., J.P., M.K.K., and Y.H. contributed equally to this work. This work was supported by the National Research Foundation of Korea (NRF) (Grant No. NRF‐2018R1C1B6004272, NRF‐2019R1A6A3A03033404, NRF‐2019R1A6A1A11044070, NRF‐2020R1A2B5B03002475, and NRF‐2019M3E6A1064709) and the Korea Basic Science Institute under the R&D program (Project No. C38530) supervised by the Ministry of Science. The authors thank Korea Basic Science Institute (KBSI) for the usage of their HRTEM and HPXPS instruments. Experiments at PLS‐II were supported in part by MSICT and POSTECH. The authors also thank Yongju Hong for assistance in HRTEM experiments.
© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
- iridium oxides
- oxidation states
- oxygen evolution reaction
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics