Impact of IrRu oxygen evolution reaction catalysts on Pt nanostructured thin films under start-up/shutdown cycling

JOURNAL OF POWER SOURCES

卷:269

Article

Cullen, David A.¹  More, Karren L.²  Atanasoska, Ljiljana L.³  Atanasoski, Radoslav T.³ 

[1] Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, TN 37831 USA

[2] Oak Ridge Natl Lab, Ctr Nanophase Mat Sci, Oak Ridge, TN 37831 USA

[3] 3M Co, Fuel Cell Components Program, St Paul, MN 55144 USA

关键词: Fuel cells;    Start-up/shutdown;    Oxygen evolution reaction;    Catalyst;    Scanning transmission electron microscopy;    X-ray photoelectron spectroscopy;   

DOI  :  10.1016/j.jpowsour.2014.06.153

来源: Elsevier

【 摘 要 】

Electron microscopy and X-ray photoelectron spectroscopy (XPS) were utilized to study the role of oxygen evolution reaction (OER) catalysts in mitigating degradation arising from start-up/shutdown events. Pt nanostructured thin films (NSTF) were coated with a Ru0.1Ir0.9 OER catalyst at loadings ranging from 1 to 10 mu g cm(-2) and submitted to 5000 potential cycles within a membrane electrode assembly. Analysis of the as-deposited catalyst showed that the Ir and Ru coating is primarily metallic, and further evidence is provided to support the previously reported interaction between Ru and the perylene-red support. Aberration-corrected scanning transmission electron microscopy and energy dispersive X-ray spectroscopy were used to observe the impact of the OER catalysts on Pt dissolution and migration into the membrane. Elemental mapping showed a high percentage of the Ir catalyst was maintained on the NSTF whisker surfaces following testing. The presence of the OER catalysts greatly reduced the smoothing of the Pt NSTF whiskers, which has been correlated with Pt dissolution and losses in electrochemically active surface area. The dissolution of both Ir and Pt led to the formation of IrPt nanoparticle clusters in the membrane close to the cathode, as well as the formation of a Pt band deeper in the membrane. Published by Elsevier B.V.

【 授权许可】

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