Local structure analysis of Pt nanoparticles on Ar-ion-irradiated glassy carbon substrate by XAFS measurements

Kimata, Tetsuya*; Yamaki, Tetsuya; Yamamoto, Shunya; Hakoda, Teruyuki; Matsumura, Daiju   ; Shimoyama, Iwao   ; Iwase, Akihiro*; Fujimura, Yuki*; Kobayashi, Tomohiro*; Terai, Takayuki*

Carbon-supported platinum (Pt) nanoparticles have been studied intensively for applications to oxygen reduction reaction (ORR) catalysts in polymer electrolyte fuel cells. The Pt nanoparticles on the Ar-ion-irradiated glassy carbon (GC) substrate were previously found to improve ORR activity. We analyzed here the local structure by XAFS measurements to clarify the mechanism of the Pt-C bonding at the Pt/GC interface, which could contribute to the observed high ORR activity. A decrease in the white-line intensity at Pt M and L edges suggests the reduction of the vacancy in the Pt 5d orbital, thereby leading to the interfacial structure with suppressed oxygen adsorbability.