Abstract
The ability of NO decomposition for titanium oxides, which crystal structure was changed by mechanical milling, has been measured. As mechanical milling methods, vibrational and planetary ball milling and mortar were employed. Using the ball millings and the mortar, the crystal structure was changed from anatase-type TiO2→TiO2II-type TiO2→rutile-type TiO2 and anatase→brookite-type TiO2→rutile, respectively. No impurity was detected after the milling by mortar, while the sample was unavoidably contaminated by the small amount of impurities after the ball milling. As for the NO decomposition, the order of the ability was anatase > brookite > TiO2II > rutile. It is found that NO2 production associated with NO decomposition was reduced when using brookite or rutile produced by mortar.
