Progress on Selective Catalytic Ammonia Oxidation (NH3-SCO) over Cu−Containing Zeolite-Based Catalysts

Abstract

The selective catalytic oxidation of ammonia into nitrogen and water vapor (NH3-SCO) has proven to be the most efficient technique for the removal of NH3 from the oxygen-containing diesel exhausts. Until now, two reviews over investigated catalysts have been published in 2015–2016 (Jabłońska et al., RCS. Adv. 2015; Appl. Catal. B: Environ. 2016). Among various NH3-SCO catalysts, Cu- and/or Fe-containing zeolites are considered as promising candidates due to their benign nature, NH3 storage capacity, very high NH3 conversion and N2 selectivity. The present review focusses only on the Cu-containing zeolites (mainly on chabazite (CHA): SSZ-13, SAPO-34) catalysts) applied in NH3-SCO starting from 2015. The synthesis/preparation methods and the state of Cu in catalysts on the activity and selectivity are highlighted. The advantages of the understanding of the reaction mechanism are reviewed. Finally, an outlook is given together with expected inspirations for future research directions in developing zeolite-based catalysts.