| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem wherein the nitrogen oxidation and reduction capacity of an SCR catalyst is lowered after hydrothermal durability treatment. <P>SOLUTION: The SCR catalyst containing SUZ-4 zeolite with an SiO<SB>2</SB>/Al<SB>2</SB>O<SB>3</SB>ratio of 12.0 or above is excellent in hydrothermal durability and has a high nitrogen oxide purifying capacity using at least one of a gas selected from ammonia, urea and organic amines as a reducing agent. Further, it is preferable to increase the nitrogen oxide reducing capacity of the SCR catalyst by supporting an active metal such as iron or copper on the SCR catalyst. <P>COPYRIGHT: (C)2010,JPO&INPIT |
