fulltext.study @t Gmail

Ethylbenzene dehydrogenation over binary FeOx–MeOy/Mg(Al)O catalysts derived from hydrotalcites

Paper ID Volume ID Publish Year Pages File Format Full-Text
41545 45892 2010 10 PDF Available
Title
Ethylbenzene dehydrogenation over binary FeOx–MeOy/Mg(Al)O catalysts derived from hydrotalcites
Abstract

A series of FeOx–MeOy/Mg(Al)O catalysts were prepared from hydrotalcite-like compounds as precursors and were tested in the ethylbenzene dehydrogenation to styrene in He atmosphere at 550 °C. The hydrotalcite-like precursors of the metal compositions of Mg3Fe0.25Me0.25Al0.5 (Me = Cu, Zn, Cr, Mn, Fe, Co and Ni) were coprecipitated from the nitrates of metal components and calcined to mixed oxides at 550 °C. After the calcination, the mixed oxides showed high surface area of 150–200 m2 gcat−1, and were mainly composed of (MgMe)(Fe3+Al)O periclase in the bulk, whereas the surface was enriched by (MgMe)(Fe3+Al)2O4 pinel. Among the Me species tested, Co2+ was the most effective, followed by Ni2+. Co2+ addition increased the activity of original FeOx/Mg(Al)O catalyst, whereas Ni2+ increased the activity at the beginning of reaction, but deactivated the catalyst during the reaction. The other metals formed isolated MeOx species in the catalyst, resulting in a decrease in the activity compared to the original FeOx/Mg(Al)O catalyst. The active Fe species exists as metastable Fe3+ on the FeOx/Mg(Al)O catalyst. By the addition of Co2+, the reduction–oxidation between Fe3+ and Fe2+ was facilitated and, moreover, the active Fe3+ species was stabilized. It is likely that the dehydrogenation proceeds on the active Fe3+ species via its reduction–oxidation assisted by Co2+.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (52 K)Download as PowerPoint slideResearch highlights▶ Styrene production by ethylbenzene dehydrogenation. ▶ FeOx–CoOy/Mg(Al)O catalyst derived from hydrotalcites. ▶ Fe3+ active species assisted by Co2+. ▶ Reduction–oxidation mechanism between Fe3+ and Fe2+.

Keywords
Ethylbenzene dehydrogenation; Styrene; FeOx–MeOy/Mg(Al)O catalyst; Hydrotalcite
First Page Preview
Ethylbenzene dehydrogenation over binary FeOx–MeOy/Mg(Al)O catalysts derived from hydrotalcites
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 390, Issues 1–2, 20 December 2010, Pages 225–234
Authors
, , , , , , , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis