Reactivity of V2O5 with TiO2ZrO2 mixed oxide: An X-ray diffraction study

Reddy, Benjaram M.; Manohar, B.; Mehdi, Safia

doi:10.1016/0022-4596(92)90029-u

Cited by 44 publications

(32 citation statements)

References 21 publications

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“…However, X-ray diffraction lines characteristic of the formation of the crystalline ZrTiO 4 compound can be observed from 600 1C and above temperatures, and whose crystallinities increase with an increase in calcination temperature. This result was consistent with those reported earlier by Daly et al [14] and Reddy et al [15]. On the other hand, Noguchi and Mizuno [16] reported that tetragonal and monoclinic ZrO 2 , and rutile TiO 2 could be produced by the decomposition of ZrTiO 4 at higher temperatures.…”

Section: Xrd Measurementssupporting

confidence: 92%

“…Furthermore, Navio and co-workers [17] detected the formation of TiO 2 in rutile phase even after calcination at 500 1C. As suggested by Reddy et al [15], the observed higher stability of ZrTiO 4 compound may presumably be due to a different preparation method adopted and the precursor compounds used for the preparation of this mixed oxide in the present study.…”

Section: Xrd Measurementsmentioning

confidence: 60%

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The effect of B2O3 addition on the crystallization of amorphous TiO2–ZrO2 mixed oxide

Mao

2007

Journal of Solid State Chemistry

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Section: Xrd Measurementssupporting

confidence: 92%

Section: Xrd Measurementsmentioning

confidence: 60%

The effect of B2O3 addition on the crystallization of amorphous TiO2–ZrO2 mixed oxide

Mao

2007

Journal of Solid State Chemistry

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“…However, no such catalytic inactive crystalline phases were noted in this study. The TiO 2 is known to interact with ZrO 2 to form crystalline ZrTiO 4 compound beyond 873 K [54]. No XRD lines pertaining to this compound were also identified.…”

Section: X-ray Powder Diffraction Analysismentioning

confidence: 97%

Highly Dispersed Ce x Zr1−x O2 Nano-Oxides Over Alumina, Silica and Titania Supports for Catalytic Applications

2008

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We have been exploring the utilization of supported ceria and ceria-zirconia nano-oxides for different catalytic applications. In this comprehensive investigation, a series of Ce x Zr 1-x O composite oxide catalysts were synthesized and subjected to thermal treatments from 773 to 1073 K to examine the influence of support on thermal stability, textural properties and catalytic activity of the ceria-zirconia solid solutions. The physicochemical characterization studies were performed using X-ray diffraction (XRD), Raman spectroscopy (RS), X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HREM), thermogravimetry and BET surface area methods. To evaluate the catalytic properties, oxygen storage/release capacity (OSC) and CO oxidation activity measurements were carried out. The XRD analyses revealed the formation of Ce 0.75 Zr 0.25 O 2 , Ce 0.6 Zr 0.4 O 2 , Ce 0.16 Zr 0.84 O 2 and Ce 0.5 Zr 0.5 O 2 phases depending on the nature of support and calcination temperature employed. Raman spectroscopy measurements in corroboration with XRD results suggested enrichment of zirconium in the Ce x Zr 1-x O 2 solid solutions with increasing calcination temperature thereby resulting in the formation of oxygen vacancies, lattice defects and oxygen ion displacement from the ideal cubic lattice positions. The HREM results indicated a well-dispersed cubic Ce x Zr 1-x O 2 phase of the size around 5 nm over all supports at 773 K and there was no appreciable increase in the size after treatment at 1073 K. The XPS studies revealed the presence of cerium in both Ce 4? and Ce 3? oxidation states in different proportions depending on the nature of support and the treatment temperature applied. All characterization techniques indicated absence of pure ZrO 2 and crystalline inactive phases between Ce-Al, Ce-Si and Ce-Ti oxides. Among the three supports employed, silica was found to stabilize more effectively the nanosized Ce x Zr 1-x O 2 oxides by retarding the sintering phenomenon during high temperature treatments, followed by alumina and titania. Interestingly, the alumina supported samples exhibited highest OSC and CO oxidation activity followed by titania and silica. Details of these findings are consolidated in this review.

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“…The 1:1 mole ratio mixed oxides and close to that composition are mostly in amorphous form due to the facile formation of TiZrO 4 compound when calcined at around 500°C [50]. The crystallinity of this compound generally increases with increasing calcination temperature beyond 600°C [59].…”

Section: Tio 2 -Zro 2 Composite Oxidesmentioning

confidence: 97%

Dehydrogenation of Ethylbenzene to Styrene with Carbon Dioxide Over ZrO2-based Composite Oxide Catalysts

et al. 2008

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We have been exploring various new catalyst systems for the utilization of carbon dioxide as a soft oxidant in the catalytic dehydrogenation of ethylbenzene (EB) to styrene. The utilization of CO 2 as a soft oxidant for the commercially important catalytic dehydrogenation of EB to styrene has received enormous attention recently due to its several attractive features. This review summarizes the results of our most recent findings on zirconia-based composite oxide catalyst systems exploited for this reaction. Under this systematic and comprehensive investigation various zirconia-based composite oxide catalysts namely/SBA-15 have been synthesized, characterized by various techniques and evaluated for the title reaction. Most of these composite oxide catalysts were found to exhibit very interesting physicochemical characteristics and exceptionally better catalytic properties for this reaction. As revealed by characterization results, a large number of acid-base sites with moderate strength are essential for a high conversion and product selectivity of this reaction with CO 2 as the soft oxidant.

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Reactivity of V2O5 with TiO2ZrO2 mixed oxide: An X-ray diffraction study

Cited by 44 publications

References 21 publications

The effect of B2O3 addition on the crystallization of amorphous TiO2–ZrO2 mixed oxide

The effect of B2O3 addition on the crystallization of amorphous TiO2–ZrO2 mixed oxide

Highly Dispersed Ce x Zr1−x O2 Nano-Oxides Over Alumina, Silica and Titania Supports for Catalytic Applications

Dehydrogenation of Ethylbenzene to Styrene with Carbon Dioxide Over ZrO2-based Composite Oxide Catalysts

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