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X-ray absorption spectroscopy measurements were performed for the C K-edge of Pt nanoparticles on Ar+-irradiated carbon supports in order to elucidate the origin of improved catalyst performance after the introduction of vacancies into the carbon support. We observed a change in the electronic structure at the interface between the Pt nanoparticles and the carbon support after vacancy introduction, which is in good agreement with theoretical results. The results indicated that vacancy introduction resulted in a drastic change in the Pt–C interactions, which likely affected the d-band center of the Pt nanoparticles and led to the enhancement of the oxygen reduction reaction in catalysts. [ABSTRACT FROM AUTHOR]

Abstract A glassy carbon (GC) substrate was irradiated with 380 keV argon ions (Ar+), and platinum nanoparticles (Pt NPs) were then deposited on it by a radio-frequency magnetron sputtering method. The interfacial effect of the Ar+-induced defects in the GC substrate on the size and electronic structure of the Pt NPs was investigated. The irradiation defects in the carbon support promoted the growth of the Pt NPs on the substrate, leading to a larger NP size. Density functional theory calculations revealed that the lattice vacancies in the graphitic structure lowered the position of the Pt d-band center via the interfacial charge transfer. This down-shift in the d-band center would be a reason for the higher catalytic activity, which was reported in our previous research. Highlights • The Pt nanoparticles were deposited on a 380 keV Ar+-irradiated carbon support. • The particle sizes on the irradiated and non-irradiated support were investigated. • A Pt electronic structure was modified by the irradiation defects of the carbon support. • We discussed how the Pt size and electronic structure affected the catalytic activity. [ABSTRACT FROM AUTHOR]