Selective oxidation of isobutane and isobutene over vanadium phosphorus oxides

Guan, Jingqi; Xu, Haiyan; Jing, Shubo; Wu, Shujie; Ma, Yuanyuan; Shao, Yanqiu; Kan, Qiubin

doi:10.1016/j.catcom.2008.09.003

Cited by 16 publications

(5 citation statements)

References 21 publications

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“…Hence, it can be suggested that the valence states of vanadium were in the range of 4–5 and the vanadium species in the synthesized catalysts were mainly in the form of (VO) 2 P 2 O 7. As shown in Table , the P2p binding energies detected were almost the same among all of the samples, which revealed that the element of P was present on the surface, this phenomenon was good as the slight excess of phosphorus helps in stabilizing the V 4+ oxidation state . As for the binding energies of oxygen, O1s, the values were very similar (532.0 eV) for all the samples, which were close to the reference, approx.…”

Section: Resultsmentioning

confidence: 99%

Effect of direct ultrasound synthesis via a sesquihydrate route on bismuth‐promoted vanadyl pyrophosphate catalysts

Goo

Yap

Lin

et al. 2019

J Chinese Chemical Soc

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A series of 1, 3, and 5% Bi-doped vanadium phosphate catalyst catalysts were prepared via sesquihydrate route using direct ultrasound method and were denoted as VPSB1, VPSB3, and VPSB5, respectively. These catalysts were synthesized solely using a direct ultrasound technique and calcined in a n-butane/air mixture. This study showed that catalyst synthesis time can be drastically reduced to only 2 hr compared to conventional 32-48 hr. All Bi-doped catalysts exhibited a wellcrystallized (VO) 2 P 2 O 7 phase. In addition, two V 5+ phases, that is, β-VOPO 4 and α II -VOPO 4 , were observed leading to an increase in the average oxidation state of vanadium. All catalysts showed V2p 3/2 at approx. 517 eV, giving the vanadium oxidation state at approx. 4.3-4.6. Field-emission scanning electron microscopy micrographs showed the secondary structure consisting of thin and small plate-like crystal clusters due to the cavitation effect of ultrasound waves. VPSB5 showed the highest amount of oxygen species removed associated with the V 5+ and V 4+ species in temperature-programmed reduction in H 2 analyses. TheX-ray absorption near edge structure (XANES) measurement showed the occurrence of vanadium oxide reductions in hydrogen gas flow, indicating the presence of V 4+ and V 5+ species. Higher average valence states of V 5+ , indicating more V 5+ phases, were present. The addition of bismuth has increased the activity and selectivity to maleic anhydride. K E Y W O R D Sbismuth, butane oxidation, direct ultrasound synthesis, selective oxidation, sesquihydrate, vanadyl pyrophosphate catalyst

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Section: Resultsmentioning

confidence: 99%

Effect of direct ultrasound synthesis via a sesquihydrate route on bismuth‐promoted vanadyl pyrophosphate catalysts

Goo

Yap

Lin

et al. 2019

J Chinese Chemical Soc

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“…/V 4? ratio in the catalysts favors the formation of MAL [12,18], although it is still controversial throughout the literature [29] that the ratio V 4? /V 5?…”

Section: Catalytic Propertiesmentioning

confidence: 98%

“…/ V 4? pair has been shown to perform a dominant role in changing the catalytic activity of VPO catalysts for selective oxidation of isobutane [18]. The different characters of such pairs on the surface and in the bulk have rarely been studied, and no detailed relationship between the variation of such pairs and catalyst preparation procedure has been established.…”

Section: Introductionmentioning

confidence: 99%

Effect of pH on the Catalytic Properties of Mo–V–Te–P–O Catalysts for Selective Oxidation of Isobutane

et al. 2009

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Mo-V-Te-P mixed oxide catalysts, prepared by a dry-up method at various pHs (in the range of about 1.0-9.0), have been tested in the partial oxidation of isobutane. The best catalytic performance was achieved over a catalyst prepared at a pH about 7.0. In this case, high selectivity to methacrolein (37.0%) at an isobutane conversion of 12.7% has been obtained at 380°C. The surface V 4? /V 5? ratios of the calcined samples were strongly influenced by the pH in the synthesized solution, which is one of the key factors in the catalytic performance for selective oxidation of isobutane.

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“…[6][7][8][9][10][11][12][13][14] The catalytic performance of both VO(PO 3 ) 2 and (VO) 2 P 2 O 7 catalysts have been evaluated in gas-phase reactions such as oxidations, oxidative dehydrogenations, and ammoxidations. [15][16][17][18][19][20][21][22][23] However, VO(PO 3 ) 2 showed poor catalytic performance in gas-phase oxidation of n-butane to maleic anhydride when compared to the high catalytic activity of (VO) 2 P 2 O 7 . The poor catalytic performance of VO(PO 3 ) 2 in n-butane oxidation, due to low activity and selectivity, has limited its application in other chemical reactions.…”

Section: Introductionmentioning

confidence: 99%

Structural Characteristics, Stability, and Activity of (VO)₂P₂O₇ and VO(PO₃)₂ Catalysts in p‐Cymene Liquid‐Phase Oxidation

Makgwane¹,

Ferg²,

Zeelie³

2010

ChemCatChem

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The post‐reaction structural characteristics of VO(PO3)2 and (VO)2P2O7 catalysts and their reusability in liquid‐phase oxidation of p‐cymene to tertiary cymene hydroperoxide (TCHP) are investigated and characterized. The VO(PO3)2 structure remains unchanged after being used for extended reaction times, whereas (VO)2P2O7 undergoes structural changes back to its precursor phase, VOHPO4⋅0.5 H2O, that affect its catalytic properties. The structure of the (VO)2P2O7 that has undergone phase changes is successfully restored by calcination under N2 flow at 750 °C for 2 h. Fresh and used catalysts show different particle morphologies, indicating that the reaction medium influences the microstructure. Both catalysts show considerable reusability with (VO)2P2O7 showing slight gradual deactivation. Taking into account the characterization and catalytic results obtained, the slight (VO)2P2O7 deactivation can probably be ascribed to the adsorption of organic compounds on the catalyst surface, which appears to initiate structural transformation of the (VO)2P2O7 catalyst under oxidation reaction conditions for extended reaction times. The VO(PO3)2 and (VO)2P2O7 catalysts showed to be effective for synthesis of the industrially important intermediate TCHP, a precursor to p‐cresol in liquid‐phase oxidation reactions.

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Selective oxidation of isobutane and isobutene over vanadium phosphorus oxides

Cited by 16 publications

References 21 publications

Effect of direct ultrasound synthesis via a sesquihydrate route on bismuth‐promoted vanadyl pyrophosphate catalysts

Effect of direct ultrasound synthesis via a sesquihydrate route on bismuth‐promoted vanadyl pyrophosphate catalysts

Effect of pH on the Catalytic Properties of Mo–V–Te–P–O Catalysts for Selective Oxidation of Isobutane

Structural Characteristics, Stability, and Activity of (VO)₂P₂O₇ and VO(PO₃)₂ Catalysts in p‐Cymene Liquid‐Phase Oxidation

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Selective oxidation of isobutane and isobutene over vanadium phosphorus oxides

Cited by 16 publications

References 21 publications

Effect of direct ultrasound synthesis via a sesquihydrate route on bismuth‐promoted vanadyl pyrophosphate catalysts

Effect of direct ultrasound synthesis via a sesquihydrate route on bismuth‐promoted vanadyl pyrophosphate catalysts

Effect of pH on the Catalytic Properties of Mo–V–Te–P–O Catalysts for Selective Oxidation of Isobutane

Structural Characteristics, Stability, and Activity of (VO)2P2O7 and VO(PO3)2 Catalysts in p‐Cymene Liquid‐Phase Oxidation

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Structural Characteristics, Stability, and Activity of (VO)₂P₂O₇ and VO(PO₃)₂ Catalysts in p‐Cymene Liquid‐Phase Oxidation