Effects of WOx modification on the activity, adsorption and redox properties of CeO2 catalyst for NOx reduction with ammonia

Novel Fe‐W‐Ce Mixed Oxide for the Selective Catalytic Reduction of NOx with NH3 at Low Temperatures

“…An obvious blue shift of the peaks corresponding to tungsten and ceria compounds can be seen compared with pure WO 3 . This may be a result of a strong interaction between tungsten and ceria species [33]. These findings are in accordance with the XRD results, which predicted also strong interaction between ceria and tungsten.…”

Effects of WO3 and SiO2 doping on CeO2–TiO2 catalysts for selective catalytic reduction of NO with ammonia

“…33 The intensities of CeO 2 peak slowly increased with the WO 3 content increasing, indicating that CeO 2 crystallites grown slowly, which may be due to the blocking effect of the CeO 2 by the impregnated tungsten oxide. 34 Accordingly, the average crystallite size calculated using the Scherrer equation is shown in The BET surface areas of CeW x TiSi y catalysts as well as total pore volumes and average pore diameters are presented in Table 2. It is clear that with WO 3 content increasing, a slight decrease in BET surface area is observed.…”

Effects of WO3 doping on stability and N2O escape of MnO –CeO2 mixed oxides as a low-temperature SCR catalyst

“…It means that W_O bonds act as acid sites for NH 3 adsorption. The increased Brønsted acid sites are mainly composed of W-OH sites arising from partially hydrated tungsten species such as W_O and W\ \O\ \W [16,21,22]. These Brønsted acid sites are more thermally stable and contribute to the higher ammonia desorption peak in Fig.…”

“…The total acidity increases from 1.9 to 6.0 μmol m −2 after WO 3 doping, which is mainly due to the increased numbers of Brønsted acid sites (NH 4 + vibrations: 1430 and 1670 cm −1 ) derived from WO x species [13,17]. The negative W_O overtone at 990 cm − 1 on W0.1Mn0.4Ce catalyst indicates the consumption of W_O bonds during the process of NH 3 adsorption [17,21]. It means that W_O bonds act as acid sites for NH 3 adsorption.…”