Papers by Author: Keiichi Inukai

Abstract: Titanium dioxide photocatalyst films were prepared by dip-coating method using titanium dioxide sol solution in order to research the H₂O addition effect on the photocatalytic activities. The sol solution was prepared with titanium tetra-isopropoxide, urea and 2-methoxyethanol, then irradiated ultraviolet light and added distilled H₂O. The substrates for the dip-coating were fused silica plates and as-prepared films were dried at 100 °C then annealed at 650 °C. The films prepared by these methods showed visible light absorption in wavelengths longer than 380 nm and accelerated photodegradation of methylene blue by visible light irradiation. Furthermore, the photocatalytic activities of these films were depending on the H₂O additions to the sol solution.

Abstract: . Preferential oxidation (PROX) of CO in the presence of H2 is an important reaction to maintain stable operation of polymer electrolyte fuel cells (PEFCs) since their anode catalyst can be poisoned by trace amount of CO. In this study, we examined PROX reactions mediated by Pt catalysts prepared using several mesoporous silica and aluminosilicate supports such as imogolite (IM), allophane (AP), silica aerogel (SAG), and an amorphous hydroxyl aluminosilicate developed in our research group (HAS). The selectivity of CO oxidation gradually decreased from 80 to 60 % with increasing temperature from 323 to 473 K for Pt/HAS catalyst whereas it increased with temperature from 10 to 40 % for Pt/IM, Pt/AP, Pt/SAG catalysts. These results indicate that Pt supported on HAS may be effective for low-temperature PROX reactions.