| 摘要 |
PROBLEM TO BE SOLVED: To provide a photocatalyst material which reduces, decomposes and removes nitrogen oxides in a gas phase or nitrogen oxides produced in a refuse disposal facility by using energy such as UV rays. SOLUTION: This photocatalyst to reduce, decompose and remove nitrogen oxides in a gas phase consists of a holladite crystalline phase expressed by formula of Ax My Sn8-y O16 . In the formula, A is one or more elements selected from K, Rb, Cs, Ca, Ba and Na, M is a bivalent or tervalent metal, however, Na is used only when M is Cr, and (x) and (y) (satisfy 0.7<2.0<=2.0 and 0.7<y<=2.0. In this purifying method of nitrogen oxides in a gas phase by using this photocatalyst, the catalyst is brought into contact with nitrogen oxides while irradiated with light in the presence of a reducing agent. Thus, nitrogen oxides are decomposed and removed under reducing conditions to be converted into nitrogen. |
