Effect of zeolite topology on NH3-SCR activity and stability of Cu-exchanged zeolites

Facile preparation, catalytic performance and reaction mechanism of MnxCo1−xOδ/3DOM-m Ti0.7Si0.2W0.1Oycatalysts for the simultaneous removal of soot and NOx

“…5,58 As the temperature increases to 150 °C, the bands (1436 cm −1 ) related to NH 3 on the catalyst surface are strengthened. 54 It should also be noted that the peaks at 3100-3600 cm −1 could be overlapping peaks of the coordinated NH 3 bound to L-acid sites and nitrate species on the surface of the catalyst at 150 °C. In the 150-250 °C range, the acid sites on the catalyst surface gradually disappeared, and the peaks representing the nitrate species (1398 and 1580 cm −1 ) appeared and the intensity increased.…”

“…In addition, the yields of N 2 O for most of the catalysts are below 20%, which still corresponds well with our expectations. 54 Tables S2 and S3 † list the comparison results for the catalytic performance of deNO x and soot combustion. Considering the different reaction conditions, the as-prepared catalysts in this work show good NO x removal performance and acceptable soot catalytic activity.…”

Theoretical Studies on the Mechanism of deNOx Process in Cu–Zn Bimetallic System—Comparison of FAU and MFI Zeolites

“…Experiments to combine transition metals with zeolites have led to the design of catalysts having higher efficiency, thermal resistance and also increased tolerance to sulfur poisoning [ 24 , 25 , 26 ]. Additionally, copper has a relatively easy redox cycle during the catalytic reaction, which facilitates the deNOx process [ 27 , 28 , 29 ]. Zinc also shows interesting catalyst promoting properties for the SCR process [ 30 , 31 ].…”

Influence of ZCuOH, Z2Cu, and Extraframework CuxOy Species in Cu-SSZ-13 on N2O Formation during the Selective Catalytic Reduction of NOx with NH3

“…25,41,50,51 In conjunction with all of these changes in the active centers, an increase in the NO 2 pressure is reported to increase N 2 O selectivity. 40,52−55 Although the presence of water between 0 and 12% does not significantly affect the standard SCR rate, 25,37 Tarach et al 56 (Cu-ZSM-5 and Cu-TNU-9) and Zhang et al 45 (Cu-ZSM-5, Cu-SAPO-34, Cu-SSZ-13) reported that an increase in water increases the N 2 O selectivity on Cu zeolites. At 523 K, Liu et al 57 observed an increase in N 2 O selectivity with increasing H 2 O from 0 to 2% and a decrease in N 2 O selectivity at water concentrations greater than 2%.…”

“…Delahay et al 53 also observed that ion-exchanging Ba 2+ into Cu-FAU decreased the N 2 O selectivity, presumably by decreasing the cage volume. A recent study by Tarach et al, 56 however, reported higher N 2 O selectivites on smallerpore Cu-ZSM-5 and Cu-TNU-9 than on larger-pore Cu-FER and Cu-Y. Utilizing DFT computations, Feng et al 47 demonstrated that the predicted energy landscape for ammonium nitrate decomposition is indistinguishable regardless of being unconfined or confined in an Al-free CHA cage.…”