Photocatalytic reduction of CO{sub 2} with H{sub 2}O on titanium oxides anchored within micropores of zeolites: Effects of the structure of the active sites and the addition of Pt
- Osaka Prefecture Univ. (Japan)
Titanium oxide species anchored within the Y-zeolite cavities by an ion-exchange exhibit a high and unique photocatalytic reactivity for the reduction of CO{sub 2} with H{sub 2}O at 328 K with a high selectivity for the formation of CH{sub 3}OH in the gas phase. The in situ photoluminescence, ESR, diffuse reflectance absorption, and XAFS (XANES and FT-EXAFS) investigations indicate that the titanium oxide species are highly dispersed within the zeolite cavities and exist in a tetrahedral coordination. The charge transfer excited state of the anchored titanium oxide species plays a significant role in the reduction of CO{sub 2} with H{sub 2}O with a high selectivity for the formation of CH{sub 3}OH, while the catalysts involving the aggregated octahedrally coordinated titanium oxide species show a high selectivity to produce CH{sub 4}, being similar to reactions on the powdered TiO{sub 2} catalysts. The addition of Pt to the anchored titanium oxide catalysts promotes the charge separation which leads to an increase in the CH{sub 4} yields in place of CH{sub 3}OH formation. 29 refs., 5 figs.
- OSTI ID:
- 535440
- Journal Information:
- Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical, Vol. 101, Issue 14; Other Information: PBD: 3 Apr 1997
- Country of Publication:
- United States
- Language:
- English
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