Catalyst for reducing nitrogen oxides

摘要

A catalyst for reducing nitrogen oxides is prepared by shaping into granules a naturally produced inorganic powdery substance composed predominantly of alpha -Fe2O3 alone or in mixture with one or more of metals selected from Groups I-b, V-a, VI-a,VII-a and VIII of the periodic Table or compounds thereof, and thereafter subjecting the granules to a heat treatment. This catalyst can be used for reductively eliminating dilute nitrogen oxides in exhaust gas by bringing the exhaust gas and a reducing agent into contact with the catalyst.