Title of article :
Overview of the practically important behaviors of zeolite-based urea-SCR catalysts, using compact experimental protocol
Author/Authors :
Krishna Kamasamudram، نويسنده , , Neal W. Currier، نويسنده , , Xu Chen، نويسنده , , Aleksey Yezerets، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2010
Abstract :
Selective catalytic reduction with NH3 (NH3-SCR technology), based on V2O5/WO3/TiO2 catalysts, has been previously commercialized for abating NOx emissions from various stationary and mobile lean-burn or diesel engines. However, meeting the uniquely stringent US EPA 2010 regulations for diesel engines required introduction of a new class of SCR catalysts, based on Cu- or Fe-exchanged zeolites. While remarkably active and stable, these new materials proved substantially more difficult than vanadia-based catalysts to operate transiently on the road, due to their much higher NH3 storage. The objective of this work was to develop a concise experimental protocol, elucidating multiple catalytic functions, steady-state and transient, of practical relevance to the mobile SCR applications. This paper provides a comprehensive overview of such functions, using select data from various representative Cu- and Fe-zeolite catalysts. While the bulk of the reported results originated directly from the developed protocol, additional experiments, validating the assumptions or clarifying unexpected experimental observations, are included.
Keywords :
SCR , NOx reduction , experimental methodology , Transient performance , NO oxidation , NO2 reduction , NH3 oxidation , NH3 storage , NH4NO3 formation , Nitrogen balance
Journal title :
CATALYSIS TODAY
Journal title :
CATALYSIS TODAY