Selective catalytic reduction of NOx with ammonia (NH3-SCR) over copper loaded LEV type zeolites synthesized with different templates

• DOI: 10.1039/d2cp01512a
• Publication Date: 2022-06-13T11:01:06Z
• Authors: Andreas Hoffmann; Michiel De Prins; Sreeprasanth Puli...; Gina Vanbutsele; Sam Smet; C. Vinod Chandran; Sambhu Radhakrishnan; Eric Breynaert; Johan A. Martens
• Keywords: Selective catalytic reduction; Silanol; Hydrothermal Synthesis; Ring size; Crystal (programming language); Template

LEV type zeolites were synthesized with four different structure-directing agents and converted to copper loaded NH3-SCR catalysts. The synthesis recipe was found impact the respective Al population in two topologically framework sites double single 6-rings, resolvable by 27Al MAS NMR spectroscopy. Hydrothermal stability be related silanol concentration, Si/Al ratio, particle size, crystal morphology, defects, external surface area, microporosity. Catalytic activity dependent on preferential siting 6-rings. Levinite using adamantylamine showed strongest preference for atoms sitting 6-ring sites, highest catalytic turnover frequency. Unfortunately, because of large loading this sample limited 0.6 wt% while other samples could up 3.3 wt%. An optimum combination hydrothermal obtained N,N'-bis-dimethylpentanediyldiammonium dibromide as agent.