Patent ID: 7794680
Filing Date: 2010-09-14
Classification: B01D,B01J,Y02C

Abstract:
1. A process for reducing a nitrogen oxide selected from nitrogen monoxide, nitrogen dioxide, and mixtures thereof comprising reacting the nitrogen oxide with at least one reducing agent selected from the group consisting of ammonia, urea, and an organic amine in the presence of a catalyst comprising a crystalline silicate containing iron in a β-framework structure wherein a SiO 2 /Fe 2 O 3 mole ratio of the crystalline silicate is in the range of 20 to 300, and at least 80% of the contained iron is an isolated iron ion Fe 3+ and at least 20% of the contained iron is an isolated iron ion Fe 3+ having a tetrahedral coordination, whereby the nitrogen oxides are selectively reduced.