Zeolite catalysts for Urea SCR

Oliver  Krocher, Paul Scherrer Institute

Metal exchanged zeolites are regarded as a potential alternative to the established vanadia based catalysts, because they function in a broad temperature window, the risk of emitting volatile and water soluble vandyl species is avoided and no disposal problems occur. Although some literature is available about ammonia SCR on powdered metal exchanged zeolites, not much is known about the SCR performance of zeolites on monoliths. Detailed results on the catalytic performance, the potentials and limitations of ion exchanged zeolites for urea SCR are presented with focus on Fe-ZSM5. Extensive physicochemical characterization of the catalyst samples helped us to gain insight into the functionality of this class of SCR catalysts.