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; ; Hatada, Motoyoshi
KURRI-TR-368, p.33 - 38, 1992/00
no abstracts in English
Hakoda, Teruyuki; Yamamoto, Shunya; Aritani, Hirofumi*; Yoshikawa, Masahito
no journal, ,
The production of noble metal catalyst particles on the surface of catalyst substrates were studied using low energy electron beams (EBs) as a radiation-induced reduction method. Porous alumina substrates were impregnated in a solution containing PtCl
ions and ethanol. The surface of the substrates was irradiated with EBs. As a result, platinum particles were produced on the surface of the substrates. The platinum particles had catalytic activity. The obtained results suggest that low energy EBs can be applied to the production of noble metal catalysts as new application of a radiation-induced reduction method.
Sugawara, Toshifumi*; Aritani, Hirofumi*; Hakoda, Teruyuki; Yoshikawa, Masahito
no journal, ,
We observed that platinum nanoparticles films were produced on the surface of a solution containing 1 mmol/L PtCl ions and 0.5-20v% ethanol by irradiating with a few tens keV electron beams (EB). The platinum films, deposited to grassy substrates, showed the fuel-cell catalytic activity. The Pt nanoparticle films prepared using a few tens keV EB induced reduction method were observed to have catalytic activity.
Sugawara, Toshifumi*; Takahashi, Ayaka*; Aritani, Hirofumi*; Shimada, Akihiko; Hakoda, Teruyuki; Sugimoto, Masaki; Yoshikawa, Masahito
no journal, ,
We observed that platinum nanoparticles films were produced on the surface of a solution containing 1 mmol/L PtCl ions and 0.5-20v% ethanol by irradiating with a few tens keV electron beams (EB). The platinum films, deposited to grassy substrates, showed the fuel-cell catalytic activity. The Pt nanoparticle films prepared using a few tens keV EB induced reduction method were observed to have catalytic activity.
Hakoda, Teruyuki; Takahashi, Ayaka*; Shimada, Akihiko; Yamamoto, Shunya; Aritani, Hirofumi*; Yamaki, Tetsuya
no journal, ,
Aqueous solutions containing 1 mmol/L AuCl
ions and 0.5-20v% alcohol (2-propanol or ethanol) were irradiated with a few tens keV electron beams (EBs). Gold (Au) films were produced on the surface of the irradiated solution. The production rate of the Au films was high at concentrations of 0.5-1v% for 2-propanol and became lower at higher concentrations. At an alcohol concentration of 0.5v%, the Au particles of the films were 5-20 nm and 5-100 nm in diameter for 2-propanol and ethanol, respectively. The XPS analysis demonstrated that the films consisted of about 85wt% of metal Au(0), 10wt% of Au(I), and a few wt% of Au(III) for 2-propanol. A Fourier transform infrared diffusion reflectance (FTIR-DR) measurement showed that CO was oxidized into CO
over the Au films loaded to TiO substrates at a temperature of 200
C, enabling us to confirm a catalytic activity.
films using electron beams and 
-raysYamamoto, Shunya; Sugimoto, Masaki; Miyashita, Atsumi; Hakoda, Teruyuki; Yamaki, Tetsuya; Mori, Toshiyuki*
no journal, ,
Platinum modified with cerium oxide (Pt-CeO
) is considered as promising cathode materials for use in polymer membrane electrolyte fuel cells. A key process to make this active is formation of highly dispersed Pt nanoparticles on a CeO surface. Therefore, there is a strong motivation for us to use this radiation technique for precipitation of the Pt nanoparticles on CeO films, which would be expected to be a model electrocatalyst of Pt-CeO. We deposited the CeO films on a SiO substrate by magnetron sputtering. The CeO films in an aqueous solution containing HPtCl
and CH
OH were irradiated with 2 MeV electron beams and 
Co -rays at 50 kGy at maximum. The detailed analysis revealed homogeneous precipitation of metallic Pt by the irradiation with both the radiations, suggesting high applicability of the radiation-induced precipitation method to the preparation of the model Pt-CeO electrocatalysts.