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Effect of water on oxidative scission of 1-butene to acetic acid over V2O5-TiO2 catalyst. Transient isotopic and kinetic study

Paper ID Volume ID Publish Year Pages File Format Full-Text
41630 45895 2011 12 PDF Available
Title
Effect of water on oxidative scission of 1-butene to acetic acid over V2O5-TiO2 catalyst. Transient isotopic and kinetic study
Abstract

The role of water in the oxidation of 1-butene to AcOH over VOx-TiO2 was investigated using spectroscopic and transient isotopic exchange methods. It was shown that the influence of water strongly depended on the temperature of reaction. In particular, DRIFTS and NH3-TPD studies confirmed the temperature influence on the acidity and the amount of adsorbed water. XPS investigations suggested that not only oxygen from vanadia, but also from the lattice of titania was involved in the oxygen transfer during the reaction. Formation of oxidation products proceeded over two types of active vanadium oxide centers, i.e., VOH and VO. Hydrated vanadium species exhibited high selectivity towards AcOH formation. On the other hand, VO centers favored total oxidation. Kinetic model was developed for an unambiguous interpretation of the experimental results. Modelled reaction constants of the formation of AcOH over VOH centers were ca. 3.5 times higher than over VO centers. At the same time, the reaction rate constant of total oxidation in the presence of water was ca. 3.2 times lower than in dry flow. Estimated values suggested that in the presence of water the number of VOH centers was substantially lower than VO sites; however their contribution to the rate of AcOH formation was much higher.

Graphical abstractThe role of water in the oxidation of 1-butene to AcOH over VOx-TiO2 was investigated using spectroscopic and transient isotopic exchange methods. In particular, DRIFTS, XPS, TPD and SSITKA methods were used. Subsequently, kinetic model was developed for an unambiguous interpretation of the experimental results.Figure optionsDownload full-size imageDownload high-quality image (28 K)Download as PowerPoint slide

Keywords
Vanadia–titania catalyst; Oxidation of 1-butene; Water; Acetic acid; O exchange
First Page Preview
Effect of water on oxidative scission of 1-butene to acetic acid over V2O5-TiO2 catalyst. Transient isotopic and kinetic study
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 391, Issues 1–2, 4 January 2011, Pages 125–136
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis