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The influence of the preparation method on the structural, acidic and redox properties of V2O5-TiO2/SO42− catalysts

Paper ID Volume ID Publish Year Pages File Format Full-Text
42539 45930 2009 8 PDF Available
Title
The influence of the preparation method on the structural, acidic and redox properties of V2O5-TiO2/SO42− catalysts
Abstract

The introduction of sulfates into vanadia-titania catalysts and the influence of the preparation method on the properties of the sulfated samples have been studied. Series of V2O5-TiO2/SO42− (VTiS) catalysts were prepared by co-precipitation, sol–gel and mechanical grinding methods and calcined at different temperatures. Their structural properties were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). Co-precipitation was by far the best preparation method in terms of maximizing the surface area and the mesoporosity. Temperature-programmed reduction (TPR) revealed that only the vanadia species were reducible. The results from XRD and FT-IR showed that V2O5 was well dispersed on the surface of TiO2. XPS showed that the surface vanadium oxide was composed of stoichiometric V2O4 and V2O5, as well as V2O3 species especially for the samples prepared by mechanical grinding. Meanwhile, titanium was present in its fully oxidized state in all the VTiS samples, and the sulfur-containing species presented an oxidation state of +6. The reaction of isopropanol (IPA) conversion in air was used to characterize the surface acid/base and redox properties. The higher activity for the IPA conversion over the VTiS catalysts as compared to TiO2 was possibly due to the generation of redox sites upon the addition of V2O5. Moreover, the surface acidic properties were enhanced and the redox properties weakened upon addition of SO42− species.

Graphical abstractV2O5-TiO2/SO42− catalysts were prepared by different methods and calcined at different temperatures. Co-precipitation was by far the best preparation method. The reaction of isopropanol conversion in air was used to probe the strength of surface acidic sites and redox properties. The surface acidic properties were enhanced and the redox properties weakened upon addition of SO42− species.Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
V2O5-TiO2/SO42−; Co-precipitation; Sol–gel; Mechanical grinding; Structural properties; Redox properties; Isopropanol conversion
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The influence of the preparation method on the structural, acidic and redox properties of V2O5-TiO2/SO42− catalysts
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 356, Issue 2, 15 March 2009, Pages 121–128
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
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Any Questions? feel free to contact us