A new V2O5–MoO3–TiO2–SO42−nanostructured aerogel catalyst for diesel DeNOxtechnology

Arfaoui, Jihène; Ghorbel, Abdelhamid; Petitto, Carolina; Delahay, Gérard

doi:10.1039/d0nj03747h

Cited by 20 publications

(14 citation statements)

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“…The authors concluded that the increase of Mn amount had a positive effect on the acidity of MnOx-CeO2/GR catalysts and contributes greatly to its high NO-SCR by NH3 activity. After sulfation of Mn-TiO2 catalyst, a new peak belonging to NH3-desorbed from strong acid sites, generated by sulfate groups, has appeared at high temperature ~ 500 °C [30,31]. It should be mentioned that the addition of cerium induces a decrease of the total acidity (mainly medium and strong ones) of the unsulfated and sulfated Mn based solids.…”

Section: Acidity and Reducibility Of Aerogel Catalystsmentioning

confidence: 99%

“…These species seem to be reduced at the same temperature range than manganese and affects its reducibility. The addition of sulfate completely hidden the reduction of other species, since, only one intense peak, corresponding to the reduction of sulfate groups, is detected at ~ 620 °C [30, 31,52] in the H2-TPR profiles of sulfated aerogel catalysts. It is worth noting that the intensity of the peak attributed to the reduction of SO4 2groups is higher in the case of Ce-Mn-TiO2-SO4 2catalyst compared to that of Mn-TiO2-SO4 2sample.…”

Section: Acidity and Reducibility Of Aerogel Catalystsmentioning

confidence: 99%

“…It is recognized that the use of the sol-gel procedure combined to supercritical drying can produce a highly structured aerogel materials with superior textural properties (high specific surface area and porosity) which can provide more active sites in the catalyst surface [29]. On the other hand, in our previous works [30,31] we have demonstrated that the addition of SO4 2groups to the composition of V2O5-CeO2-TiO2 and V2O5-MoO3-TiO2 aerogel catalysts enhances both the NO conversion and N2 selectivity at high temperatures. However, the NO-SCR activity of Ce-Mn-TiO2-SO4 2aerogel system has not yet been studied.…”

Section: Introductionmentioning

confidence: 99%

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New Mn-TiO2 aerogel catalysts for the low-temperature selective catalytic reduction of NOx

Arfaoui

Ghorbel

Petitto

et al. 2021

J Sol-Gel Sci Technol

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A new series of Mn-based catalysts (Mn-TiO2, Ce-Mn-TiO2, Mn-TiO2-SO4 2and Ce-Mn-TiO2-SO4 2-) were successfully elaborated using the sol gel method associated to supercritical drying approach for the low temperature NO-SCR by NH3. The physicochemical properties of aerogel powders were examined by XRD, N2-Physisorption at 77 K, NH3-TPD, H2-TPR, and DRUV-Vis spectroscopy. It was shown that all the catalysts develop essentially the diffraction peaks of TiO2 anatase phase and are characterized by a nanometer size (ranging between ~ 5 and 9 nm), developed mesoporous texture, high surface area (SBET 104 m 2 /g) and large porosity (VPT  0.24 cm 3 /g). The incorporation of Ce and/or SO4 2influences differently the structural, textural, acidic and redox properties of Mn derived sol gel catalysts and consequently affects their SCR activity. High NO conversions ( 75 %) into essentially N2O are obtained at low temperatures (150-270 °C) over Mn-TiO2 and Ce-Mn-TiO2 aerogel systems. The addition of sulfate modifies the nature of Mn species and noticeably reduces the low temperature reactivity of catalysts (T  300 °C). However, it induces, thanks to the contribution of many strong acid sites, a substantial increase of the NO conversion into N2 at higher temperatures (T  300 °C) leading to highly active and N2-selective Mn-TiO2-SO4 2and Ce-Mn-TiO2-SO4 2sulfated catalysts. Above 90 % NO conversion into N2 (100 %) was reached, in the NO-SCR by NH3, over the new Ce-Mn-TiO2-SO4 2aerogel catalyst, in the 450-500 °C temperature range.

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Section: Acidity and Reducibility Of Aerogel Catalystsmentioning

confidence: 99%

Section: Acidity and Reducibility Of Aerogel Catalystsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

New Mn-TiO2 aerogel catalysts for the low-temperature selective catalytic reduction of NOx

Arfaoui

Ghorbel

Petitto

et al. 2021

J Sol-Gel Sci Technol

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“…Based on the above discussion, and taking into account (i) the advantages of using the sol gel method for the preparation of highly active aerogel catalysts for the DeNOx process ( [45][46][47][48] [49]. It was revealed that the surface acidity plays an important role in the adsorption and activation of ammonia, especially at high temperature.…”

Section: Introductionmentioning

confidence: 99%

Promotional effect of ceria on the catalytic behaviour of new V2O5–WO3–TiO2 aerogel solids for the DeNOx process

Arfaoui

Ghorbel

Petitto

et al. 2021

Journal of Solid State Chemistry

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New cerium and/or tungsten modified V 2 O 5 -TiO 2 aerogel catalysts (V 2 O 5 -TiO 2 ,V 2 O 5 -WO 3 -TiO 2, V 2 O 5 -CeO 2 -TiO 2 and V 2 O 5 -WO 3 -CeO 2 -TiO 2 ) were successfully developed, by associating the sol gel procedure and supercritical drying approach. A combination of various analytical techniques, including XRD, N 2 -Physisorption at 77 K, DRUV-Vis spectroscopy, NH 3 -TPD and H 2 -TPR, was used to characterize the obtained solids. Their catalytic performances were evaluated in the low temperature NO-SCR by NH 3 . The results reveal that all the materials exhibit high cristallinity of TiO 2 anatase phase and developed mesoporous texture. The addition of tungsten (W) increases the surface acidity of V 2 O 5 -TiO 2 and thereby enhances its reactivity at high temperatures (> 420 °C). However, the addition of cerium (Ce) improves the redox properties of the latter catalyst and increases significantly its NO-SCR reactivity, especially at low temperatures. The NO-SCR activity increases over the aerogel systems, in the 200-400 °C temperature range, following this order:was found to be the most active catalyst for converting NO into N 2 (with 60 % and 90 % NO conversions at 250 °C and between 320 and 420 °C, respectively). The highest SCR activity of this new aerogel solid if compared to the other samples was essentially correlated with a good reactivity of its acidic and redox sites which in turn was related to the existence of strong interactions between cerium and the other active elements (mostly Ce↔ V and Ce ↔ W).

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“…Our particular interest in TiO 2 -supported MoO 3 is primarily derived from molybdenum oxide's ability to act as both a Lewis acid and base (29)(30)(31), as well as a redox-active promoter (32)(33)(34). Many important reactions such as hydrodesulfurization, selective oxidation, metathesis of olefins, and selective NOx reduction are catalyzed and or promoted by molybdenum oxides (2,(35)(36)(37)(38)(39)(40)(41)(42)(43). Further, titanium dioxide is often used as a reducible oxide support material which itself is capable of acid/base and redox chemistries.…”

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confidence: 99%

Creating self-assembled arrays of mono-oxo (MoO ₃ ) ₁ species on TiO ₂ (101) via deposition and decomposition of (MoO ₃ ) _n oligomers

Doudin

Collinge

Gurunathan

et al. 2021

Proc. Natl. Acad. Sci. U.S.A.

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Hierarchically ordered oxides are of critical importance in material science and catalysis. Unfortunately, the design and synthesis of such systems remains a key challenge to realizing their potential. In this study, we demonstrate how the deposition of small oligomeric (MoO3)1–6 clusters—formed by the facile sublimation of MoO3 powders—leads to the self-assembly of locally ordered arrays of immobilized mono-oxo (MoO3)1 species on anatase TiO2(101). Using both high-resolution imaging and theoretical calculations, we reveal the dynamic behavior of the oligomers as they spontaneously decompose at room temperature, with the TiO2 surface acting as a template for the growth of this hierarchically structured oxide. Transient mobility of the oligomers on both bare and (MoO3)1-covered TiO2(101) areas is identified as key to the formation of a complete (MoO3)1 overlayer with a saturation coverage of one (MoO3)1 per two undercoordinated surface Ti sites. Simulations reveal a dynamic coupling of the reaction steps to the TiO2 lattice fluctuations, the absence of which kinetically prevents decomposition. Further experimental and theoretical characterizations demonstrate that (MoO3)1 within this material are thermally stable up to 500 K and remain chemically identical with a single empty gap state produced within the TiO2 band structure. Finally, we see that the constituent (MoO3)1 of this material show no proclivity for step and defect sites, suggesting they can reliably be grown on the (101) facet of TiO2 nanoparticles without compromising their chemistry.

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A new V₂O₅–MoO₃–TiO₂–SO₄²⁻nanostructured aerogel catalyst for diesel DeNO_xtechnology

Abstract: New V2O5-MoO3-TiO2-SO42- nanostructured aerogel system, containing V and Mo amounts representative of V2O5-MoO3/TiO2 commercial SCR catalyst, was developed via the one step sol gel method combined to supercritical drying approach...

Cited by 20 publications

References 97 publications

New Mn-TiO2 aerogel catalysts for the low-temperature selective catalytic reduction of NOx

New Mn-TiO2 aerogel catalysts for the low-temperature selective catalytic reduction of NOx

Promotional effect of ceria on the catalytic behaviour of new V2O5–WO3–TiO2 aerogel solids for the DeNOx process

Creating self-assembled arrays of mono-oxo (MoO ₃ ) ₁ species on TiO ₂ (101) via deposition and decomposition of (MoO ₃ ) _n oligomers

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A new V2O5–MoO3–TiO2–SO42−nanostructured aerogel catalyst for diesel DeNOxtechnology

Abstract: New V2O5-MoO3-TiO2-SO42- nanostructured aerogel system, containing V and Mo amounts representative of V2O5-MoO3/TiO2 commercial SCR catalyst, was developed via the one step sol gel method combined to supercritical drying approach...

Cited by 20 publications

References 97 publications

New Mn-TiO2 aerogel catalysts for the low-temperature selective catalytic reduction of NOx

New Mn-TiO2 aerogel catalysts for the low-temperature selective catalytic reduction of NOx

Promotional effect of ceria on the catalytic behaviour of new V2O5–WO3–TiO2 aerogel solids for the DeNOx process

Creating self-assembled arrays of mono-oxo (MoO 3 ) 1 species on TiO 2 (101) via deposition and decomposition of (MoO 3 ) n oligomers

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Product

Resources

About

A new V₂O₅–MoO₃–TiO₂–SO₄²⁻nanostructured aerogel catalyst for diesel DeNO_xtechnology

Creating self-assembled arrays of mono-oxo (MoO ₃ ) ₁ species on TiO ₂ (101) via deposition and decomposition of (MoO ₃ ) _n oligomers