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Grzybowska-S̈wierkosz, B.

doi:10.1023/a:1027256116098

Cited by 135 publications

(92 citation statements)

References 160 publications

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“…For many years the typical catalysts for the ODHE reported in the literature consisted of vanadium oxide supported on different metal oxides [6,7] and recently unconventional materials such as nanocatalysts [8,9], catalysts derived from heteropolyacids [10] and carbon nanotubes [11] have demonstrated to be efficient in this reaction but their catalytic performance is still far from the best catalytic systems, which are NiO-based catalysts [12][13][14][15][16][17][18][19][20][21][22] and MoVNb-mixed metal oxide materials [23][24][25][26].…”

Section: Introductionmentioning

confidence: 99%

Promoted NiO Catalysts for the Oxidative Dehydrogenation of Ethane

et al. 2014

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Section: Introductionmentioning

confidence: 99%

Promoted NiO Catalysts for the Oxidative Dehydrogenation of Ethane

et al. 2014

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“…3 Earlier experimental studies indicate that this catalytic system is of high performance when it consists of a monolayer of V 2 O 5 upon a TiO 2 (anatase) substrate, showing activity and selectivity not observed in the unsupported V 2 O 5 or TiO 2 anatase. 2,4 The enhanced catalytic performance can be attributed to a synergetic effect between the active phase and the support. In order to unravel the role of the TiO 2 support on a V 2 O 5 monolayer catalyst, ab initio methods can help to provide a better understanding of the relation between structure and reactivity.…”

Section: Introductionmentioning

confidence: 99%

Theoretical Study of the Effect of (001) TiO₂Anatase Support on V₂O₅

et al. 2010

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The effect of (001) TiO 2 anatase support on the electronic and catalytic properties of a V 2 O 5 monolayer is analyzed using density functional theory (DFT). The catalyst is represented by both clusters and periodic slabs. Using two experimentally relevant models of monolayer V 2 O 5 /TiO 2 (anatase) catalyst, both weak and strong interactions between a V 2 O 5 monolayer and the TiO 2 support have been investigated. In the first model, where a crystallographic (001) V 2 O 5 layer is placed on top of the (001) TiO 2 support, the weak interaction between vanadia and titania does not result in a major reconstruction of the active phase. Nevertheless, the changes in the electronic properties of the system are evident. The deposition of the vanadia monolayer on the titania substrate results in charge redistribution, enhancing the Lewis acidity of vanadium and the chemical hardness above the vanadyl oxygen, and in a shift of the Fermi level to lower binding energies accompanied by a reduction in the band gap. In the second model, where the (001) titania anatase structure is extended with a VO 2 film terminated by half a monolayer of vanadyl oxygen, apart from a similar electronic effect, the strong interaction of the vanadia phase with the titania support resulting from a high order of epitaxy has an important effect on the structure of the active phase. Atomic hydrogen adsorption is most favorable on the vanadyl oxygen of all the investigated surfaces, while the adsorption energy on this site increases by ∼10 kJ/mol due to the weak interaction between vanadia and titania and is further increased by ∼50 kJ/mol as a stronger interaction between the two phases is achieved, all in agreement with the increase in the negative electrostatic potential above the vanadyl site. The observed trends in the reactivity of the oxygen sites in H adsorption for the different catalyst models are successfully explained in terms of a frontier orbital analysis. IntroductionTransition metal oxides are widely used as catalysts for the oxidation of hydrocarbons. Especially vanadium oxide based catalysts are among the most active for the oxidation of both aliphatic and aromatic hydrocarbons. An important example of such a catalyst is V 2 O 5 /TiO 2 (anatase), which is used in industry as an effective catalyst for the production of phthalic anhydride from o-xylene.1,2 For the anatase support, although the (101) surface is thermodynamically more stable, the (100) and (001) faces are found in the industrial TiO 2 powders.3 Earlier experimental studies indicate that this catalytic system is of high performance when it consists of a monolayer of V 2 O 5 upon a TiO 2 (anatase) substrate, showing activity and selectivity not observed in the unsupported V 2 O 5 or TiO 2 anatase.2,4 The enhanced catalytic performance can be attributed to a synergetic effect between the active phase and the support. In order to unravel the role of the TiO 2 support on a V 2 O 5 monolayer catalyst, ab initio methods can help to provide a better understanding of the rel...

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“…Despite its importance and extensive research on the influence of water on supported metal oxide catalysts there are still fundamental aspects, which have not been addressed in the literature adequately to their importance, such as changes in catalyst dispersion and their potential correlation with structural changes. 1 XPS can provide direct information on the dispersion of supported metal oxide catalysts such as vanadium oxide supported on SiO 2 , Al 2 O 3 and TiO 2 . 2 However, many of the previous studies were performed on samples exposed to air before being introduced into the XPS chamber without further treatment.…”

Section: Introductionmentioning

confidence: 99%

Direct correlation of the dispersion and structure in vanadium oxide supported on silica SBA-15

Heß

2007

Journal of Catalysis

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Raman, UV-Vis and X-ray photoelectron spectroscopy were combined in one experimental setup to directly study the interplay between structure and dispersion of SBA-15 supported vanadium oxide during dehydration. The fully hydrated catalyst is slightly reduced but consists mainly of V 5+ species with pseudo-octahedral V coordination strongly resembling the xerogel V 2 O 5 ·1.2H 2 O. After dehydration a highly dispersed surface anadium oxide species with tetrahedrally coordinated vanadium and significantly smaller ensemble size is formed. v

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Cited by 135 publications

References 160 publications

Promoted NiO Catalysts for the Oxidative Dehydrogenation of Ethane

Promoted NiO Catalysts for the Oxidative Dehydrogenation of Ethane

Theoretical Study of the Effect of (001) TiO₂Anatase Support on V₂O₅

Direct correlation of the dispersion and structure in vanadium oxide supported on silica SBA-15

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Untitled

Cited by 135 publications

References 160 publications

Promoted NiO Catalysts for the Oxidative Dehydrogenation of Ethane

Promoted NiO Catalysts for the Oxidative Dehydrogenation of Ethane

Theoretical Study of the Effect of (001) TiO2Anatase Support on V2O5

Direct correlation of the dispersion and structure in vanadium oxide supported on silica SBA-15

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Theoretical Study of the Effect of (001) TiO₂Anatase Support on V₂O₅