fulltext.study @t Gmail

The effect of support on redox properties and methanol-oxidation activity of vanadia catalysts

Paper ID Volume ID Publish Year Pages File Format Full-Text
41625 45895 2011 6 PDF Available
Title
The effect of support on redox properties and methanol-oxidation activity of vanadia catalysts
Abstract

The effect of support composition on the catalytic properties of isolated mono-vanadates was studied using reaction rates for the methanol-oxidation reaction and oxygen binding from coulometric titration measurements on 2.5 wt% V2O5/ZrO2, 2.5 wt% V2O5/TiO2, and 5 wt% V2O5/Al2O3. Although a review of the redox properties for the bulk oxides V2O5, ZrV2O7, AlVO4, Mg3(VO4)2, and CeVO4 showed that the environment surrounding the V cations can have a dramatic effect on the redox properties, the majority of sites on supported catalysts showed nearly identical properties, with ΔG of oxidation being −375 ± 25 kJ/mol at 748 K. The steady-state turnover frequencies for methanol oxidation were also similar (within a factor of 3) on each of the supports over the temperature range from 463 to 528 K. Finally, methanol-oxidation rates in the absence of oxygen over the oxidized vanadia/titania catalyst at 443 K demonstrated that all of the vanadia sites were active for the reaction and exhibited a similar rate to that observed in the presence of oxygen, showing that the reaction follows a Mars-van Krevelen mechanism.

Graphical abstractThe effect of support composition on the catalytic properties of isolated mono-vanadates was studied using reaction rates for the methanol-oxidation reaction and oxygen binding energy from coulometric titration measurements.Figure optionsDownload full-size imageDownload high-quality image (52 K)Download as PowerPoint slide

Keywords
Methanol oxidation; Formaldehyde; Vanadia; Support effects; Zirconia; Titania; Alumina; Redox properties
First Page Preview
The effect of support on redox properties and methanol-oxidation activity of vanadia catalysts
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 391, Issues 1–2, 4 January 2011, Pages 86–91
Authors
, , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis