Fe-Zeolite Functionality, Durability, and Deactivation Mechanisms in the Selective Catalytic Reduction (SCR) of NOx with Ammonia

Ammonia Desorption Peaks Can Be Assigned to Different Copper Sites in Cu/SSZ-13

“…Such improvement is largely made possible by the development of increasingly efficient catalysts, for instance for the ammonia selective catalytic reduction (NH 3 -SCR) reaction in lean-burn engine exhausts. Most recently, small-pore materials such as the zeolite Cu/SSZ-13 have become popular for ammonia SCR as a result of their excellent hydrothermal stability compared to the more established medium-pore zeolites [1].…”

Impact of Copper Loading on NH3-Selective Catalytic Reduction, Oxidation Reactions and N2O Formation over Cu/SAPO-34

“…Vanadia-based catalysts then became common and later on, metal-exchanged zeolites [1,[4][5][6]. Most recently, small-pore materials such as the zeolite Cu/SSZ-13 and the silicoaluminophosphate Cu/SAPO-34, have become popular subjects of research [7][8][9].…”

Study on the catalytic activity and hydrothermal stability of one-pot synthesized Fe-based FER zeolites for NH3-SCR

“…9A, the NO x conversion of the three fresh OP-Fe-FER-x zeolites are apparently higher than that of IM-Fe/SSZ-20 during the whole temperature window (100-550 °C) range. According to numerous literature reports, 38,[50][51][52][53] strong temperature dependencies exist between the NH 3 -SCR catalytic activity and various Fe species in zeolites; the isolated Fe 3+ species are the dominant active sites for NH 3 -SCR below 300 °C, while the main active sites for NH 3 -SCR at high temperatures (>300 °C) are dimers and/or oligomeric Fe 3+ species which can also catalyse the undesirable side reactions (i.e. ammonia oxidation).…”