The role of CO2 in the dehydrogenation of propane over WOx–VOx/SiO2.
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| Title: | The role of CO2 in the dehydrogenation of propane over WOx–VOx/SiO2. |
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| Authors: | Ascoop, Isabelle1, Galvita, Vladimir V.2 Vladimir.Galvita@UGent.be, Alexopoulos, Konstantinos2, Reyniers, Marie-Françoise2, Van Der Voort, Pascal1, Bliznuk, Vitaliy3, Marin, Guy B.2 |
| Source: | Journal of Catalysis. Mar2016, Vol. 335, p1-10. 10p. |
| Subjects: | Carbon dioxide, Dehydrogenation, Propane, Tungsten oxides, Atmospheric pressure, X-ray diffraction |
| Abstract: | A series of WO x –VO x catalysts supported on porous silica, with W/V molar ratios between 0 and 0.6, are examined for propane dehydrogenation in the presence and absence of CO 2 from 500 °C to 600 °C and at atmospheric pressure. Catalysts characterization using temperature programmed reduction (H 2 -TPR), temperature programmed oxidation (CO 2 -TPO), Raman spectroscopy, X-ray diffraction and transmission electron microscopy shows that the combination of the two metal components allows retention of VO x dispersion during the reaction. CO 2 has the ability to oxidize V 2 O 3 to V 2 O 4 and participates in the oxidative dehydrogenation of propane to propylene. When the reaction is carried out with D 2 present in the feed together with C 3 H 8 and CO 2 (D 2 :C 3 H 8 :CO 2 = 1:1:1), only 45% of the resulting water contains D 2 O. This confirms that the reaction follows the oxidative dehydrogenation route of propane but is also accompanied by the reverse water gas shift reaction in combination with the non-oxidative dehydrogenation route. Moreover, one of the major roles of CO 2 is the suppression of the formation of surface carbon. A partially reduced vanadia dimer was used to represent the active site and density functional theory (DFT) calculations were performed. This allowed to confirm that propane dehydrogenation in the presence of CO 2 can proceed simultaneously via direct oxidative dehydrogenation and non-oxidative dehydrogenation followed by the reverse water gas shift reaction. According to the DFT-calculated Gibbs free energy profile at 600 °C, the activation of the secondary C H bond of propane ( E DFT,act = 158 kJ/mol) is rate-limiting, while re-oxidation of the catalyst with CO 2 is potentially much faster. The catalyst with a W/V = 0.1 M ratio has the highest C 3 H 6 average turnover frequency but higher selectivities were obtained with W/V = 0.6. In agreement with the value predicted from DFT, the experimental apparent activation energy for all investigated W/V ratios is similar and varies from 127 ± 11 kJ/mol to 147 ± 12 kJ/mol with W/V molar ratios between 0 and 0.6. [ABSTRACT FROM AUTHOR] |
| Copyright of Journal of Catalysis is the property of Academic Press Inc. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 112948579 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: The role of CO2 in the dehydrogenation of propane over WOx–VOx/SiO2. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Ascoop%2C+Isabelle%22">Ascoop, Isabelle</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Galvita%2C+Vladimir+V%2E%22">Galvita, Vladimir V.</searchLink><relatesTo>2</relatesTo><i> Vladimir.Galvita@UGent.be</i><br /><searchLink fieldCode="AR" term="%22Alexopoulos%2C+Konstantinos%22">Alexopoulos, Konstantinos</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Reyniers%2C+Marie-Françoise%22">Reyniers, Marie-Françoise</searchLink><relatesTo>2</relatesTo><br /><searchLink fieldCode="AR" term="%22Van+Der+Voort%2C+Pascal%22">Van Der Voort, Pascal</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Bliznuk%2C+Vitaliy%22">Bliznuk, Vitaliy</searchLink><relatesTo>3</relatesTo><br /><searchLink fieldCode="AR" term="%22Marin%2C+Guy+B%2E%22">Marin, Guy B.</searchLink><relatesTo>2</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+Catalysis%22">Journal of Catalysis</searchLink>. Mar2016, Vol. 335, p1-10. 10p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Carbon+dioxide%22">Carbon dioxide</searchLink><br /><searchLink fieldCode="DE" term="%22Dehydrogenation%22">Dehydrogenation</searchLink><br /><searchLink fieldCode="DE" term="%22Propane%22">Propane</searchLink><br /><searchLink fieldCode="DE" term="%22Tungsten+oxides%22">Tungsten oxides</searchLink><br /><searchLink fieldCode="DE" term="%22Atmospheric+pressure%22">Atmospheric pressure</searchLink><br /><searchLink fieldCode="DE" term="%22X-ray+diffraction%22">X-ray diffraction</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: A series of WO x –VO x catalysts supported on porous silica, with W/V molar ratios between 0 and 0.6, are examined for propane dehydrogenation in the presence and absence of CO 2 from 500 °C to 600 °C and at atmospheric pressure. Catalysts characterization using temperature programmed reduction (H 2 -TPR), temperature programmed oxidation (CO 2 -TPO), Raman spectroscopy, X-ray diffraction and transmission electron microscopy shows that the combination of the two metal components allows retention of VO x dispersion during the reaction. CO 2 has the ability to oxidize V 2 O 3 to V 2 O 4 and participates in the oxidative dehydrogenation of propane to propylene. When the reaction is carried out with D 2 present in the feed together with C 3 H 8 and CO 2 (D 2 :C 3 H 8 :CO 2 = 1:1:1), only 45% of the resulting water contains D 2 O. This confirms that the reaction follows the oxidative dehydrogenation route of propane but is also accompanied by the reverse water gas shift reaction in combination with the non-oxidative dehydrogenation route. Moreover, one of the major roles of CO 2 is the suppression of the formation of surface carbon. A partially reduced vanadia dimer was used to represent the active site and density functional theory (DFT) calculations were performed. This allowed to confirm that propane dehydrogenation in the presence of CO 2 can proceed simultaneously via direct oxidative dehydrogenation and non-oxidative dehydrogenation followed by the reverse water gas shift reaction. According to the DFT-calculated Gibbs free energy profile at 600 °C, the activation of the secondary C H bond of propane ( E DFT,act = 158 kJ/mol) is rate-limiting, while re-oxidation of the catalyst with CO 2 is potentially much faster. The catalyst with a W/V = 0.1 M ratio has the highest C 3 H 6 average turnover frequency but higher selectivities were obtained with W/V = 0.6. In agreement with the value predicted from DFT, the experimental apparent activation energy for all investigated W/V ratios is similar and varies from 127 ± 11 kJ/mol to 147 ± 12 kJ/mol with W/V molar ratios between 0 and 0.6. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of Catalysis is the property of Academic Press Inc. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.jcat.2015.12.015 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 10 StartPage: 1 Subjects: – SubjectFull: Carbon dioxide Type: general – SubjectFull: Dehydrogenation Type: general – SubjectFull: Propane Type: general – SubjectFull: Tungsten oxides Type: general – SubjectFull: Atmospheric pressure Type: general – SubjectFull: X-ray diffraction Type: general Titles: – TitleFull: The role of CO2 in the dehydrogenation of propane over WOx–VOx/SiO2. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Ascoop, Isabelle – PersonEntity: Name: NameFull: Galvita, Vladimir V. – PersonEntity: Name: NameFull: Alexopoulos, Konstantinos – PersonEntity: Name: NameFull: Reyniers, Marie-Françoise – PersonEntity: Name: NameFull: Van Der Voort, Pascal – PersonEntity: Name: NameFull: Bliznuk, Vitaliy – PersonEntity: Name: NameFull: Marin, Guy B. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 03 Text: Mar2016 Type: published Y: 2016 Identifiers: – Type: issn-print Value: 00219517 Numbering: – Type: volume Value: 335 Titles: – TitleFull: Journal of Catalysis Type: main |
| ResultId | 1 |