Co-Exchanged IM5, a Stable Zeolite for the Selective Catalytic Reduction of NO in the Presence of Water and SO2

• Published in: Industrial & engineering chemistry research 2003-04, Vol.42 (8), p.1538-1542
• Main Authors: Palomares, Antonio E, Prato, José G, Corma, Avelino
• Format: Article
• Language: English
• Subjects: Applied sciences; Atmospheric pollution; Catalysis; Catalysts: preparations and properties; Chemistry; Exact sciences and technology; General and physical chemistry; General processes of purification and dust removal; Pollution; Prevention and purification methods; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie020345l

IM5 is a recently discovered zeolite that presents a high hydrothermal stability and, when exchanged with cobalt, shows a high activity for the selective catalytic reduction of NO with propane. The catalytic behavior of a cobalt-exchanged IM5 zeolite is compared with that of a cobalt-exchanged ZSM5 zeolite. The state of the cobalt in the zeolite and the influence of the partial pressure of oxygen, reaction temperature, and the presence of water and SO2 are studied. It is shown that cobalt is mainly as Co2+ in a tetrahedral environment, although the presence of a small amount of other cobalt states cannot be rejected. The material is very active for the selective catalytic reduction of NO x with propane at 723 K and, what is important, with a high oxygen concentration. The presence of possible catalyst poisons such as SO2 and water does not result in a deactivation of the Co−IM5.