Impact of IrRu Oxygen Evolution Reaction Catalysts on Pt Nanostructured Thin Films under Start-Up/Shutdown Cycling

Journal Article · Wed Jan 01 00:00:00 EST 2014 · Journal of Power Sources

DOI:https://doi.org/10.1016/j.jpowsour.2014.06.153· OSTI ID:1154816

Cullen, David A ^[1]; More, Karren Leslie ^[1]; Atanasoska, Liliana ^[2]; Atanasoski, Radoslav ^[2]

---

1. ORNL
2. 3M, Industrial Mineral Products Division

Electron microscopy and X-ray photoelectron spectroscopy (XPS) methods have been 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 g/cm2 and submitted to 5,000 potential cycles within a membrane electrode assembly. Analysis of the as-deposited catalyst showed that 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 through 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.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
• Sponsoring Organization: USDOE
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1154816
• Journal Information: Journal of Power Sources, Vol. 269, Issue 00; ISSN 0378-7753
• Country of Publication: United States
• Language: English