Pt–CeOx thin film catalysts for PEMFC

• The Pt–CeOx thin film catalyst was deposited by rf sputtering on the nanostructured GDL.
• The Pt content of the anode catalyst was 4 μg cm−2 of MEA.
• PEMFC test at 65 °C gave maximum power density PDmax = 330 mW cm−2.
• As prepared Pt–ceria films contains platinum in form of Pt2,4+ ions.
• At PEMFC working conditions Pt4+ is transformed to metallic Pt whilst Pt2+ remains stable.

Platinum is the mostly used element in catalysts for fuel cell technology, but its high price limits large-scale applications. Platinum doped cerium oxide represents an alternative solution due to very low loading, typically few micrograms per 1 cm2, at the proton exchange membrane fuel cell (PEMFC) anode. High efficiency is achieved by using magnetron sputtering deposition of cerium oxide and Pt of 30 nm thick nanoporous films on large surface carbon nanoparticle substrates. Thin film techniques permits to grow the catalyst film characterized by highly dispersed platinum, mostly in ionic Pt2+ state. Such dispersed Pt species show high activity and stability.These new materials may help to substantially reduce the demand for expensive noble-metals in catalytic applications.We measured Pt–CeOx thin film anode catalyst activity in a hydrogen PEMFC and compared it with performance of a standard reference cell. Photoelectron spectroscopy was used to investigate chemical composition of Pt–CeOx induced by the catalyst interaction with hydrogen. Nanostructured character of the catalyst was confirmed by electron microscopy.

Figure optionsDownload high-quality image (91 K)Download as PowerPoint slide