´
DATE AND HARUTA
224
surface. Actually, Bond et al. proposed the reaction mech-
anism for CO oxidation that involves hydroxyl species (4).
More recently, Boccuzzi et al. have found that the presence
of moisture is crucial for the reaction over Au/TiO2 at 90 K
(23). Further spectroscopic studies will be required to elu-
cidate the entire mechanism involving water molecule for
CO oxidation catalyzed by gold.
ACKNOWLEDGMENT
The authors thank T. Ohmi at the School of Engineering, Tohoku
University, for his instruction of ultraclean technology.
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4. CONCLUSIONS
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