Synthesis of highly dispersed platinum nanoparticles on Ti-containing mesoporous silica using photo-assisted deposition.
A simple and unique route to synthesize the nano-size Pt particles using mesoporous silica support including single-site Ti-oxide moiety (Ti-HMS) under UV-light irradiation has been developed. By the photo-assisted deposition (PAD) method, a Pt precursor can be deposited from aqueous solution of H2PtCl6 directly on the photo-excited isolated Ti-oxide moiety. The subsequent reduction with H2 generates the nano-sized Pt metal particles (PAD-Pt/Ti-HMS). The deposition of Pt precursor onto the Ti-HMS can be recognized by the observation of the decrease in the intensity of the preedge in the Ti K-edge XANES spectrum, demonstrating that the Pt precursor underwent anchoring on the single framework Ti4+ center of Ti-HMS under UV-light irradiation. The lower intensity of the Pt-Pt bond of the PAD-Pt/Ti-HMS than that of Pt foil in the Fourier transforms of Pt L(III)-edge EXAFS spectra clearly suggests the formation of the Pt nanoparticles. The PAD-Pt/Ti-HMS exhibited the higher catalytic activity for the hydrogenation of nitrobenzene to aniline and the NO reduction than the catalyst prepared by the conventional impregnation.
Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
Sayoko
S
Shironita
Kohsuke
K
Mori
Tetsutaro
T
Ohmichi
Eiji
E
Taguchi
Hirotaro
H
Mori
Hiromi
H
Yamashita