Enhanced Reoxidation of Vanadia by NO2 in the Fast SCR Reaction

Koebel, Manfred; Madia, Giuseppe; Raimondi, Fabio; Wokaun, Alexander

doi:10.1006/jcat.2002.3624

Cited by 168 publications

(79 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Then the in situ formed NO 2 reoxidizes the reduced catalytic sites, refreshing quantitatively NO to the gas (explaining why no NO consumption was observed). If NO 2 is directly injected, the reoxidation of vanadium also occurs, in agreement with the observations of Koebel et al [83]. But if NO is injected without O 2 , this loop is not activated because the production of NO 2 is impossible, leading to a reduction of the catalyst.…”

Section: Influence Of No Xsupporting

confidence: 76%

Revisiting the Behaviour of Vanadia-Based Catalysts in the Abatement of (Chloro)-Aromatic Pollutants: Towards an Integrated Understanding

et al. 2009

View full text Add to dashboard Cite

For several years, the authors study VO x /TiO 2 catalytic formulations in the context of the oxidative abatement of aromatics, possibly chlorinated, from polluted air. This paper revisits their main findings and understandings. Although VO x /TiO 2 catalysts, when upgraded with Mo or W oxides, are already used in industrial applications, it is shown that the systematic investigation (i) of the reasons why optimized synthesis and formulations are indeed efficient, (ii) of the nature of the sites responsible for the adsorption of the pollutants and their catalytic transformation, and (iii) of the corresponding mechanisms, is a valuable approach to identify guidelines and strategies for further improving the catalysts. The origin of the beneficial effects brought by WO x and MoO x to VO x /TiO 2 , and by the use of a sulphated titania support, is addressed, as well as the impact on the catalysts behaviour and performances of molecules inevitably present in a combustion exhaust gas, like CO and NO x co-pollutants and water. The behaviours of a chloroaromatic molecule, like chlorobenzene, and an oxygen containing-heterocyclic molecule, like furan and dimethylfuran, are then compared and discussed in the debate of their selection as representative model compounds for the catalytic abatement of dioxins. In this context, it is shown that strategies developed to improve the performances of VO x /TiO 2 formulations to abate Cl-aromatics, could be detrimental for cyclic molecules containing O-heteroatom, as entire dioxins. Finally, an integrated view of the catalytic process is presented by envisaging the case of a complex mixture, closer to the real application of gaseous effluent cleaning.

show abstract

Section: Influence Of No Xsupporting

confidence: 76%

Revisiting the Behaviour of Vanadia-Based Catalysts in the Abatement of (Chloro)-Aromatic Pollutants: Towards an Integrated Understanding

et al. 2009

View full text Add to dashboard Cite

show abstract

“…A similar trend of desorption was observed for all of the catalysts, except the catalyst calcined at 700 C, where a higher calcination temperature resulted in a reduced production of the oxidizing material. When both NO and NO 2 were included into the feed, a fast SCR may have occurred when compared with the standard SCR of NO Koebel et al, 2002aKoebel et al, , 2002bTronconi et al, 2007). The oxidation activity tests for the conversion of NO to NO 2 by O 2 on the Mn/ TiO 2 catalysts prepared at different calcination temperatures were performed (Figure 7).…”

Section: No Oxidation Activitymentioning

confidence: 99%

Effect of the Mn oxidation state and lattice oxygen in Mn-based TiO₂ catalysts on the low-temperature selective catalytic reduction of NO by NH₃

Lee

Park

Kim

et al. 2012

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

TiO 2 -supported manganese oxide catalysts formed using different calcination temperatures were prepared by using the wetimpregnation method and were investigated for their activity in the low-temperature selective catalytic reduction (SCR) of NO by NH 3 with respect to the Mn valence and lattice oxygen behavior. The surface and bulk properties of these catalysts were examined using Brunauer-Emmett-Teller (BET) surface area, X-ray diffraction (XRD), temperature-programmed reduction (TPR), and temperature-programmed desorption (TPD). Catalysts prepared using lower calcination temperatures, which contained Mn 4þ , displayed high SCR activity at low temperatures and possessed several acid sites and active oxygen. The TPD analysis determined that the Brönsted and Lewis acid sites in the Mn/TiO 2 catalysts were important for the low-temperature SCR at 80$160 and 200$350 C, respectively. In addition, the available lattice oxygen was important for attaining high NO to NO 2 oxidation at low temperatures.Implications: Recently, various Mn catalysts have been evaluated as SCR catalysts. However, there have been no studies on the relationship of adsorption and desorption properties and behavior of lattice oxygen according to the valence state for manganese oxides (MnO x ). Therefore, in this study, the catalysts were prepared by the wet-impregnation method at different calcination temperatures in order to show the difference of manganese oxidation state. These catalysts were then characterized using various physicochemical techniques, including BET, XRD, TPR, and TPD, to understand the structure, oxidation state, redox properties, and adsorption and desorption properties of the Mn/TiO 2 catalysts.

show abstract

“…Therefore, the suitable amount of CeO 2 was helpful to improve the low temperature De-NO x activity of catalysts, CeO 2 which had strong oxygen storage capacity combined with V 2 O 5 which had strong oxidation performance [17], improved cycle efficiency and cycle frequency of catalysts active sites, and promoted the conversion level of V 4+ to V 5+ [18], thus inspired the fast SCR reaction [19].…”

Section: Resultsmentioning

confidence: 99%

Effects of SO2 on the low temperature selective catalytic reduction of NO by NH3 over CeO2-V2O5-WO3/TiO2 catalysts

Qiang

et al. 2017

Front. Environ. Sci. Eng.

View full text Add to dashboard Cite

Enhanced Reoxidation of Vanadia by NO2 in the Fast SCR Reaction

Cited by 168 publications

References 14 publications

Revisiting the Behaviour of Vanadia-Based Catalysts in the Abatement of (Chloro)-Aromatic Pollutants: Towards an Integrated Understanding

Revisiting the Behaviour of Vanadia-Based Catalysts in the Abatement of (Chloro)-Aromatic Pollutants: Towards an Integrated Understanding

Effect of the Mn oxidation state and lattice oxygen in Mn-based TiO₂ catalysts on the low-temperature selective catalytic reduction of NO by NH₃

Effects of SO2 on the low temperature selective catalytic reduction of NO by NH3 over CeO2-V2O5-WO3/TiO2 catalysts

Contact Info

Product

Resources

About

Enhanced Reoxidation of Vanadia by NO2 in the Fast SCR Reaction

Cited by 168 publications

References 14 publications

Revisiting the Behaviour of Vanadia-Based Catalysts in the Abatement of (Chloro)-Aromatic Pollutants: Towards an Integrated Understanding

Revisiting the Behaviour of Vanadia-Based Catalysts in the Abatement of (Chloro)-Aromatic Pollutants: Towards an Integrated Understanding

Effect of the Mn oxidation state and lattice oxygen in Mn-based TiO2 catalysts on the low-temperature selective catalytic reduction of NO by NH3

Effects of SO2 on the low temperature selective catalytic reduction of NO by NH3 over CeO2-V2O5-WO3/TiO2 catalysts

Contact Info

Product

Resources

About

Effect of the Mn oxidation state and lattice oxygen in Mn-based TiO₂ catalysts on the low-temperature selective catalytic reduction of NO by NH₃