The Influence of Ceric Oxide on Phase Composition and Activity of Iron Oxide Catalysts
Author(s)
Aleksandr A. Lamberov,
Ekaterina V. Dementyeva,
Dmitriy I. Vavilov,
Olga V. Kuzmina,
Rinat R. Gilmullin,
Ekaterina A. Pavlova
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.
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.
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.
References
[1] N. V. Dvoretsky, E. G. Stepanov, G. R. Kotelnikova and V. V. Yun, “Formation Catalystically Active Ferrite of Potassium,” Chemical Fundamentals of Catalysts Formation: Interuniversity Collected Scientific Papers, Kinetics and Catalysis Affairs, Ivanovo, 1988. [2] T. Hirano, “Active Phase in Potassium-Promoted Iron Oxide Catalyst for Dehydrogenation of Ethylbenzene,” Applied Catalysis, Vol. 26, 1986, pp. 81-90. doi:10.1016/S0166-9834(00)82543-9 [3] I. Serafin, A. Kotarba, M. Grzywa and Z. Sojka, “Quenching of Potassium Loss from Styrene Catalyst: Effect of Cr Doping on Stabilization of the K2Fe22O34 Active Phase,” Journal of Catalysis, Vol. 239, No. 1, 2006, pp. 137-144. doi:10.1016/j.jcat.2006.01.026 [4] V. M. Busygin, H. H. Gilmanov and S. V. Trifonov, “Catalyst for Dehydrogenation of Olefin and Alkylaromatic Hydrocarbons,” RF Patent No. 226675, 2004. [5] M. Baier, O. Hofstadt, W. J. P?pel and H. Petersen, “Catalyst for Dehydrogenating Ethylbenzene to Produce Styrene,” US Patent No. 6551958, 2003. [6] N. Dulamita and A. Maicaneanu, “Ethylbenzene Dehydrogenation on Fe2O3-Cr2O3-K2CO3 Catalysts Promoted with Transitional Metal Oxides,” Applied Catalysis A: General, Vol. 287, No. 1, 2005, pp. 9-18. doi:10.1016/j.apcata.2005.02.037 [7] E. G. Stepanov, “Scientific Basics of Disintegrational Technology of Manufacturing Fresh Catalysts and Processing of Deactivated Catalysts of Petrochemical Processes,” Dr. Thesis, Yaroslavl State Technical University, Yaroslavl, 2005. [8] A. Trovarelli, C. Leitenburg, M. Boaro and G. Dolcetti, “The Utilization of Ceria in Industrial Catalysis,” Catalysis Today, Vol. 50, No. 2, 1999, pp. 353-367. doi:10.1016/S0920-5861(98)00515-X [9] J. Surman, D. Majda, A. Rafalska-Lasocha, P. Kustrowski, L. Chmielarz and R. Dziembaj, “Potassium Ferrites Formation in Promoted Hematite Catalysts for Dehydrogenation. Thermal and Structural Analyses,” Journal of Thermal Analysis and Calorimetry, Vol. 65, No. 2, 2001, pp. 445-450. doi:10.1023/A:1017920802391 [10] T. G. Zhdanova, R. A. Kuznetsova, A. S. Okuneva and N. K. Loginova, “Separate Identification of Potassium Compaunds in Iron-Chrompotassium Catalyst,” Promyshlennost SK (Synthetic Rubber Industry), No. 3, 1986, pp. 5-8. [11] A. I. Leonov, “High Temperature Chemistry of Cerium Oxygen Compounds,” Leningrad, 1969. [12] N. C. Pramanic, T. I. Bhuiyan, M. Nakaniahi, T. Fujii, J. Takada and S. I. Seok, “Synthesis and Characterization of Cerium Substituted Hematite by Sol-Gel Method,” Materials Letters, Vol. 59, No. 28, 2005, pp. 3783-3787. doi:10.1016/j.matlet.2005.06.056 [13] H. H. Gilmanov, A. A. Lamberov, E. V. Dementyeva, E. V. Shatochina, A. M. Gubaidullina and A. V. Ivanova, “Influence of Conditions of Heat Treatment on Formation Polyferrite Phases of Iron-Potassium Catalyst of Dehydrogenation,” Neorganicheskie Materialy (Inorganic materials), Vol. 44, No. 1, 2008, pp. 9-15. [14] G. K. Boreskov, “Heterogeneous Catalysis,” Мoscow, 1988.
[1] N. V. Dvoretsky, E. G. Stepanov, G. R. Kotelnikova and V. V. Yun, “Formation Catalystically Active Ferrite of Potassium,” Chemical Fundamentals of Catalysts Formation: Interuniversity Collected Scientific Papers, Kinetics and Catalysis Affairs, Ivanovo, 1988. [2] T. Hirano, “Active Phase in Potassium-Promoted Iron Oxide Catalyst for Dehydrogenation of Ethylbenzene,” Applied Catalysis, Vol. 26, 1986, pp. 81-90. doi:10.1016/S0166-9834(00)82543-9 [3] I. Serafin, A. Kotarba, M. Grzywa and Z. Sojka, “Quenching of Potassium Loss from Styrene Catalyst: Effect of Cr Doping on Stabilization of the K2Fe22O34 Active Phase,” Journal of Catalysis, Vol. 239, No. 1, 2006, pp. 137-144. doi:10.1016/j.jcat.2006.01.026 [4] V. M. Busygin, H. H. Gilmanov and S. V. Trifonov, “Catalyst for Dehydrogenation of Olefin and Alkylaromatic Hydrocarbons,” RF Patent No. 226675, 2004. [5] M. Baier, O. Hofstadt, W. J. P?pel and H. Petersen, “Catalyst for Dehydrogenating Ethylbenzene to Produce Styrene,” US Patent No. 6551958, 2003. [6] N. Dulamita and A. Maicaneanu, “Ethylbenzene Dehydrogenation on Fe2O3-Cr2O3-K2CO3 Catalysts Promoted with Transitional Metal Oxides,” Applied Catalysis A: General, Vol. 287, No. 1, 2005, pp. 9-18. doi:10.1016/j.apcata.2005.02.037 [7] E. G. Stepanov, “Scientific Basics of Disintegrational Technology of Manufacturing Fresh Catalysts and Processing of Deactivated Catalysts of Petrochemical Processes,” Dr. Thesis, Yaroslavl State Technical University, Yaroslavl, 2005. [8] A. Trovarelli, C. Leitenburg, M. Boaro and G. Dolcetti, “The Utilization of Ceria in Industrial Catalysis,” Catalysis Today, Vol. 50, No. 2, 1999, pp. 353-367. doi:10.1016/S0920-5861(98)00515-X [9] J. Surman, D. Majda, A. Rafalska-Lasocha, P. Kustrowski, L. Chmielarz and R. Dziembaj, “Potassium Ferrites Formation in Promoted Hematite Catalysts for Dehydrogenation. Thermal and Structural Analyses,” Journal of Thermal Analysis and Calorimetry, Vol. 65, No. 2, 2001, pp. 445-450. doi:10.1023/A:1017920802391 [10] T. G. Zhdanova, R. A. Kuznetsova, A. S. Okuneva and N. K. Loginova, “Separate Identification of Potassium Compaunds in Iron-Chrompotassium Catalyst,” Promyshlennost SK (Synthetic Rubber Industry), No. 3, 1986, pp. 5-8. [11] A. I. Leonov, “High Temperature Chemistry of Cerium Oxygen Compounds,” Leningrad, 1969. [12] N. C. Pramanic, T. I. Bhuiyan, M. Nakaniahi, T. Fujii, J. Takada and S. I. Seok, “Synthesis and Characterization of Cerium Substituted Hematite by Sol-Gel Method,” Materials Letters, Vol. 59, No. 28, 2005, pp. 3783-3787. doi:10.1016/j.matlet.2005.06.056 [13] H. H. Gilmanov, A. A. Lamberov, E. V. Dementyeva, E. V. Shatochina, A. M. Gubaidullina and A. V. Ivanova, “Influence of Conditions of Heat Treatment on Formation Polyferrite Phases of Iron-Potassium Catalyst of Dehydrogenation,” Neorganicheskie Materialy (Inorganic materials), Vol. 44, No. 1, 2008, pp. 9-15. [14] G. K. Boreskov, “Heterogeneous Catalysis,” Мoscow, 1988.