N₂O Formation during NH₃-SCR over Different Zeolite Frameworks: Effect of Framework Structure, Copper Species, and Water

The formation characteristics of N2O were investigated with respect to copper-functionalized zeolites, i.e., Cu/SSZ-13 (CHA), Cu/ZSM-5 (MFI), and Cu/BEA (BEA) compared the corresponding zeolites in H form as references elucidate effect framework structure, copper addition, water. Temperature-programmed reduction hydrogen showed that CHA has a higher concentration Cu2+ (Z2Cu) MFI BEA. characterizations catalyst activity results highlight structure favors high ammonium nitrate (AN) comparison Moreover, AN decomposition found be promoted presence Cu species. On contrary, lower was observed from Cu/CHA during standard fast SCR reactions, which is proposed due highly stabilized inside zeolite cages. other hand, significant amounts released heating AN, implying pros cons stability for possible uncontrolled transient conditions. Additionally, important effects water found, where hinders increases selectivity NO2 instead N2O. Thus, less available forming This also conditions all Cu/zeolites exhibited continuous