| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a β-type iron silicate catalyst that has a catalytic performance capable of efficiently removing nitrogen oxide over a wide temperature range, particularly over a relatively low temperature range of up to 200°C, and a hydrothermal durability, and is excellent in handleability, and a method for removing nitrogen oxide using the same. <P>SOLUTION: A β-type iron silicate used herein has a SiO<SB>2</SB>/Fe<SB>2</SB>O<SB>3</SB>molar ratio of 50-150, a fluorine content of ≤400 ppm relative to the dry weight of a crystal, has a half width (FWHM) of a crystal diffraction (302) surface of 0.16-0.24° and contains all or part of iron in a β-skeleton structure. The β-type iron silicate is obtained by crystallizing a raw material mixture through a hydrothermal treatment, provided that the raw material mixture contains an alkali metal other than Na<SP>+</SP>in particular and is free of fluorine. The catalyst for removing nitrogen oxide comprising the β-type iron silicate is used for reducing and removing nitrogen oxide. <P>COPYRIGHT: (C)2011,JPO&INPIT |
