Influence of reducibility of vanadium–magnesium mixed oxides on the oxidative dehydrogenation of propane

Balderas-Tapia, L.; Hernández-Pérez, I.; Schacht, P.; Córdova, I.; Aguilar‐Ríos, G.

doi:10.1016/j.cattod.2005.07.025

Cited by 38 publications

(17 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The reason can be ascribed to the formation of monovanadate species stabilised by the incorporation of V into the support during catalyst preparation. This result confirms the known importance of V site-isolation in improving selectivity for the ODH reaction 2,3,18,24,[54][55][56][57][58] .…”

Section: Acs Paragon Plus Environmentsupporting

confidence: 84%

Spectroscopic Enlightening of the Local Structure Of VO_X Active Sites in Catalysts for the Odh of Propane

et al. 2012

View full text Add to dashboard Cite

Site isolation of V active sites has been often correlated to catalytic performance for the oxidative dehydrogenation (ODH) of propane to propylene. In particular, catalyst selectivity seems favoured by high V dispersion. The latter property is hardly attainable by traditional preparation methods, especially by impregnation except at very low V loading, which however may lead to a too high surface exposure of the acidic sites of the support. In this paper, the effect of the preparation procedure on catalyst properties has been investigated, particularly considering catalysts prepared by flame pyrolysis, a synthesis method which induced a very high V dispersion also at relatively high vanadium loading.Transmission electron microscopy also allowed us to assess V oxide dispersion depending on both the support type and the preparation method. Furthermore, the local structure of the V active sites has been deeply investigated by X-ray Absorption Spectroscopy, allowing us to propose a possible structure of the active sites.The average oxidation state of surface V species was then studied by X-ray Photoelectron Spectroscopy (XPS), showing a role of V oxidation state on catalyst selectivity. The catalytic performance has been interpreted on the basis of V species and catalyst acidity (as measured by IR spectroscopy), another fundamental parameter that in turn results to be correlated with V dispersion on different supports. More selective catalysts were indeed characterized by the presence of weaker Brønsted acidic sites.Keywords: Oxidative dehydrogenation (ODH) of propane; Propylene production; V-based catalysts; X-ray absorption. Page 2 of 53 ACS Paragon Plus EnvironmentThe Journal of Physical Chemistry 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 3 -IntroductionLight olefins are important building blocks for polymers and intermediates industry 1 . The need for light olefins is progressively growing, with a higher rate for propene, leading to the necessity of alternative production routes 2 . Direct dehydrogenation can be an interesting alternative when low value feedstock is available. However, it is an endothermal reaction needing a high energy input, it is equilibrium controlled and the catalyst may be easily deactivated by coking. The oxidative dehydrogenation (ODH) of light paraffins to the corresponding olefins has been proposed as a means to overcome all these limitations. In addition, oxygen limits severe catalyst coking 3 . In spite of the considerable attention paid to this process and testified by a certain number of patents (see e.g. 4,5 and references therein), the ODH technology can be hardly considered mature and it has not yet reached industrial application due to selectivity issues. Indeed, oxygen should ideally consume H 2 , but paraffins and (most of all) olefins combustion is an unavoidable side reaction, w...

show abstract

Section: Acs Paragon Plus Environmentsupporting

confidence: 84%

Spectroscopic Enlightening of the Local Structure Of VO_X Active Sites in Catalysts for the Odh of Propane

et al. 2012

View full text Add to dashboard Cite

show abstract

“…The shoulder at around 820-840 • C shows the reduction to V 3+ . The shifts of the peak temperatures from the lower vanadium loadings indicate that the reduction of the corresponding oxygen species becomes more difficult in the samples with high vanadium content [35].…”

Section: Temperature Programmed Reduction After Oxidationmentioning

confidence: 99%

“…3(c)), oxygenates are dominant in the product profile when 2.5VSr-HAp is used as the catalyst. This is due to the strongly acidic strontium hydroxyapatite in the presence of V 2 O 5 containing V O bonds, where V 5+ in octahedral coordination results in the incorporation of oxygen in the intermediate reaction products, leading to formation of oxygenate compounds [35].…”

Section: -Octenementioning

confidence: 99%

Studies towards a mechanistic insight into the activation of n-octane using vanadium supported on alkaline earth metal hydroxyapatites

Dasireddy

Friedrich

Singh

2013

Applied Catalysis A: General

View full text Add to dashboard Cite

“…Considerable attention has been paid to the development of catalysts with high selectivity to propylene in the ODH. A V/MgO system was found to be one of the best in terms of activity and performance stability [2][3][4].…”

Section: Introductionmentioning

confidence: 97%

“…rate of coke deposition, mg/min) °°°F ig 4. The temperature dependence of apparent reaction order (n) for coke formation during the ODH of propane in the presence of N 2 O (9 vol%) over the aerogel 8%VO x /MgO catalyst…”

mentioning

confidence: 99%

Nanocrystalline aerogel VOx/MgO as a catalyst for oxidative dehydrogenation of propane

Mishakov

Ilyina

Bedilo

et al. 2009

React Kinet Catal Lett

View full text Add to dashboard Cite

show abstract

Influence of reducibility of vanadium–magnesium mixed oxides on the oxidative dehydrogenation of propane

Cited by 38 publications

References 26 publications

Spectroscopic Enlightening of the Local Structure Of VO_X Active Sites in Catalysts for the Odh of Propane

Spectroscopic Enlightening of the Local Structure Of VO_X Active Sites in Catalysts for the Odh of Propane

Studies towards a mechanistic insight into the activation of n-octane using vanadium supported on alkaline earth metal hydroxyapatites

Nanocrystalline aerogel VOx/MgO as a catalyst for oxidative dehydrogenation of propane

Contact Info

Product

Resources

About

Influence of reducibility of vanadium–magnesium mixed oxides on the oxidative dehydrogenation of propane

Cited by 38 publications

References 26 publications

Spectroscopic Enlightening of the Local Structure Of VOX Active Sites in Catalysts for the Odh of Propane

Spectroscopic Enlightening of the Local Structure Of VOX Active Sites in Catalysts for the Odh of Propane

Studies towards a mechanistic insight into the activation of n-octane using vanadium supported on alkaline earth metal hydroxyapatites

Nanocrystalline aerogel VOx/MgO as a catalyst for oxidative dehydrogenation of propane

Contact Info

Product

Resources

About

Spectroscopic Enlightening of the Local Structure Of VO_X Active Sites in Catalysts for the Odh of Propane

Spectroscopic Enlightening of the Local Structure Of VO_X Active Sites in Catalysts for the Odh of Propane