Advances in Chemical Engineering and Science

Volume 2, Issue 1 (January 2012)

ISSN Print: 2160-0392   ISSN Online: 2160-0406

Google-based Impact Factor: 1.15  Citations  h5-index & Ranking

The Influence of Ceric Oxide on Phase Composition and Activity of Iron Oxide Catalysts

HTML  Download Download as PDF (Size: 733KB)  PP. 28-33  
DOI: 10.4236/aces.2012.21004    4,233 Downloads   7,929 Views  

ABSTRACT

The process of dehydrogenation of methyl butenes to isoprene is conducted in the presence of iron oxide catalysts whose composition may include oxides of alkaline metals, alkaline earth metals, and transition metals. Catalysts of latest generation can also contain oxides of rare earth elements, particularly cerium oxide. However there is no any common opinion concerning its effect on catalytic properties of iron oxide catalysts. It is well known that ceric oxide has a positive effect on the quantity and stability of active centers and can play a critical role in a redox cycle of the dehydrogenation process. By means of differential thermal analysis, dispersion analysis and X-ray phase analysis, it was found in present study that introducing of ceric oxide promotes the decrease in hematite crystallite sizes. At the same time, it prevents potassium polyferrites formation, with the equilibrium of topochemical reaction between ferric oxide and po tassium carbonates moving predominantly to the formation of intermediate products–monoferrite systems, having greater catalytic activity. The increase in potassium monoferrite content results in dispersion of particles in the Fe2O3-K2CO3-СеО2 system that is accompanied by modification of texture characteristics. For this catalyst composition, the optimum concentration of ceric oxide (8.7 wt.%), leading to the formation of a certain ratio of mono- and polyferrite phases, was found. If more than 8.7 wt.% of СеО2 is introduced, the modification of texture characteristics of catalyst samples takes place, that negatively affects their selectivity.

Cite this paper

A. Lamberov, E. Dementyeva, D. Vavilov, O. Kuzmina, R. Gilmullin and E. Pavlova, "The Influence of Ceric Oxide on Phase Composition and Activity of Iron Oxide Catalysts," Advances in Chemical Engineering and Science, Vol. 2 No. 1, 2012, pp. 28-33. doi: 10.4236/aces.2012.21004.

Cited by

No relevant information.

Copyright © 2020 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.