Structure-reactivity relationships in VOx/CexZr1−xO2 catalysts used for low-temperature NH3-SCR of NO

Vuong, Thanh Huyen; Radnik, Jörg; Kondratenko, Evgenii V.; Schneider, Mat­thias; Armbruster, Udo; Brückner, Angelika

doi:10.1016/j.apcatb.2016.03.063

Cited by 49 publications

(34 citation statements)

References 53 publications

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“…The VO X site is effectively attached to the surface of the support and the redox properties of the catalysts determine the catalytic activity, rather than the Lewis and Brønsted surface acidic sites in the catalytic system. 15,16 Aer 250 C, VO X /TiO 2 -Ce 0.9 Zr 0.1 O 2 showed excellent catalytic activity and maintained excellent selectivity and thermal stability with NO conversion rate > 97%, N 2 selectivity > 97.5% and temperature window is 250-400 C, which is inseparable from the existence of low-valence V and mediumstrong acidic sites. The former is benecial to increase the activity of the catalyst, and the latter is advantageous for improving the thermal stability of the catalyst.…”

Section: Xps Analysismentioning

confidence: 97%

“…[10][11][12][13][14] Thanh Huyen Vuong and coworkers have investigated the relations between structural properties and catalytic performance in VO X /Ce X Ti 1ÀX O 2 and VO X /Ce X Zr 1ÀX O 2 catalysts, respectively. 15,16 The results indicates that VO X sites effectively attach to the support surface and the redox properties of the materials governs catalytic activity rather than Lewis and Brønsted surface acidic sites in this catalytic system. All above mentioned researches reveal the importance of oxygen mobility in catalytic reactions.…”

Section: Introductionmentioning

confidence: 94%

“…19,20 Differently, the Mars-van Krevelen mechanism of Ce-based solid solution catalyst has been clearly claried. 15,16 We expect that adding this structure to traditional catalysts in another way can bring different effects and further optimize this catalytic system. In this work, the core-shell structure carrier of TiO 2 and Ce 0.9 Zr 0.1 O 2 was prepared by precipitation method, and loaded VO X on the carrier by impregnation method.…”

Section: Introductionmentioning

confidence: 99%

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VO_X supported on TiO₂–Ce_0.9Zr_0.1O₂ core–shell structure catalyst for NH₃-SCR of NO

et al. 2019

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Section: Xps Analysismentioning

confidence: 97%

Section: Introductionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

VO_X supported on TiO₂–Ce_0.9Zr_0.1O₂ core–shell structure catalyst for NH₃-SCR of NO

et al. 2019

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“…visible as further reduction of V 4+ to V 3+ ), although a V 4+ /V 3+ redox pair was also reported for V-based SCR catalysts. 56 DFT modeling predicted 5-fold coordination of V (square pyramidal geometry with 5 O atoms at approx. 2 Å) and one additional O atom at a distance of approx.…”

Section: Pre-edge Centroid Position / Evmentioning

confidence: 99%

NH₃-SCR over V–W/TiO₂ Investigated by Operando X-ray Absorption and Emission Spectroscopy

et al. 2019

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V-W/TiO2 based catalysts, which are used for the removal of NOx from the exhaust of diesel engines and stationary sources via Selective Catalytic Reduction with NH3 (NH3-SCR), were studied by operando X-ray absorption spectroscopy and emerging photon-in/photon-out techniques. In order to minimize the influence of highly X-ray absorbing tungsten and the fluorescence of titanium we used a high energy resolution fluorescence setup that is able to separate efficiently the V Kβ1,3 emission lines and additionally allows to record valence-to-core (vtc) X-ray emission lines. The High Energy Resolution Fluorescence Detected X-ray Absorption Spectroscopy (HERFD-XAS) and vtc X-ray Emission Spectroscopy (vtc-XES) proved to be the only way to perform operando V K edge X-ray spectroscopic study on industrially relevant V-W/TiO2 catalysts so far. The V-W/TiO2 and V/TiO2 samples were synthesized by incipient wetness impregnation and grafting and exhibit high activity towards NH3-SCR. Raman spectroscopy showed that they mainly contained highly dispersed, isolated and polymeric V-oxo species. HERFD-XAS and XES identified redox cycling of vanadium species between V 4+ and V 5+. However, no direct chemical bond between V and N was observed. As result of the obtained information we suggest that the primary role of V species in SCR is to provide redox sites, whereas, adsorption and reaction of NOx and NHx species may occur via the neighboring O atoms or on the acidic support.

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“…The active component is the dominant factor affecting vanadium-based catalyst performance, and it can be divided into single vanadium oxide VO x [10,11] and multi-metal oxide compounds such as VO x -WO 3 [12], VO x -CeO x [8]. V 2 O 5 catalyst is a kind of structure-sensitive catalyst, whose activity is affected by the structure and coverage of V 2 O 5 , the crystal form of catalyst support, and the modification element.…”

Section: Composition Of Vanadium Based Catalystmentioning

confidence: 99%

Research Status and Prospect on Vanadium-Based Catalysts for NH3-SCR Denitration

Zhang

Chen

et al. 2018

Materials

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Selective catalytic reduction of NOx with NH3 is one of the most widely used technologies in denitration. Vanadium-based catalysts have been extensively studied for the deNOx process. V2O5/WO3(MoO3)TiO2 as a commercial catalyst has excellent catalytic activity in the medium temperature range. However, it has usually faced several problems in practical industrial applications, including narrow windows of operation temperatures, and the deactivation of catalysts. The modification of vanadium-based catalysts will be the focus in future research. In this paper, the chemical composition of vanadium-based catalysts, catalytic mechanism, the broadening of the temperature range, and the improvement of erosion resistance are reviewed. Furthermore, the effects of four major systems of copper, iron, cerium and manganese on the modification of vanadium-based catalysts are introduced and analyzed. It is worth noting that the addition of modified elements as promoters has greatly improved the catalytic performance. They can enhance the surface acidity, which leads to the increasing adsorption capacity of NH3. Surface defects and oxygen vacancies have also been increased, resulting in more active sites. Finally, the future development of vanadium-based catalysts for denitration is prospected. It is indicated that the main purpose for the research of vanadium-based modification will help to obtain safe, environmentally friendly, efficient, and economical catalysts.

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Structure-reactivity relationships in VOx/CexZr1−xO2 catalysts used for low-temperature NH3-SCR of NO

Cited by 49 publications

References 53 publications

VO_X supported on TiO₂–Ce_0.9Zr_0.1O₂ core–shell structure catalyst for NH₃-SCR of NO

VO_X supported on TiO₂–Ce_0.9Zr_0.1O₂ core–shell structure catalyst for NH₃-SCR of NO

NH₃-SCR over V–W/TiO₂ Investigated by Operando X-ray Absorption and Emission Spectroscopy

Research Status and Prospect on Vanadium-Based Catalysts for NH3-SCR Denitration

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Structure-reactivity relationships in VOx/CexZr1−xO2 catalysts used for low-temperature NH3-SCR of NO

Cited by 49 publications

References 53 publications

VOX supported on TiO2–Ce0.9Zr0.1O2 core–shell structure catalyst for NH3-SCR of NO

VOX supported on TiO2–Ce0.9Zr0.1O2 core–shell structure catalyst for NH3-SCR of NO

NH3-SCR over V–W/TiO2 Investigated by Operando X-ray Absorption and Emission Spectroscopy

Research Status and Prospect on Vanadium-Based Catalysts for NH3-SCR Denitration

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Product

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VO_X supported on TiO₂–Ce_0.9Zr_0.1O₂ core–shell structure catalyst for NH₃-SCR of NO

VO_X supported on TiO₂–Ce_0.9Zr_0.1O₂ core–shell structure catalyst for NH₃-SCR of NO

NH₃-SCR over V–W/TiO₂ Investigated by Operando X-ray Absorption and Emission Spectroscopy