| 摘要 |
An SCR catalyst including iron-containing ²-type zeolite has high NO X reducing performance at a high temperature in the presence of a reducing agent, but does not have the sufficient reducing performance at a low temperature (not higher than 200 °C). A high NO X reduction rate of at least 45% at a temperature not higher than 200 °C is achieved by an SCR catalyst containing iron-containing ²-type zeolite having a full width at half maximum (FWHM) on the X-ray crystal diffraction (302) plane of from 0.28 to 0.34° and a weight loss on heating to 900 °C after hydration treatment of from 15.0 to 18.0 % by weight. The SCR catalyst can be manufactured by calcining iron-containing ²-type zeolite at 700 to 850 °C under an atmosphere of a water vapor concentration of not more than 5% by volume. |
