Ethylbenzene dehydrogenation over FeOx/(Mg,Zn)(Al)O catalysts derived from hydrotalcites: Role of MgO as basic sites

Handle URI:
http://hdl.handle.net/10754/600103
Title:
Ethylbenzene dehydrogenation over FeOx/(Mg,Zn)(Al)O catalysts derived from hydrotalcites: Role of MgO as basic sites
Authors:
Balasamy, Rabindran J.; Tope, Balkrishna B.; Khurshid, Alam; Al-Ali, Ali A S; Atanda, Luqman A.; Sagata, Kunimasa; Asamoto, Makiko; Yahiro, Hidenori; Nomura, Kiyoshi; Sano, Tsuneji; Takehira, Katsuomi; Al-Khattaf, Sulaiman S.
Abstract:
A series of Mg3-xZnxFe0.5Al0.5 mixed oxide catalysts derived from hydrotalcites were tested in the ethylbenzene dehydrogenation to styrene in He atmosphere at 550 °C. The catalysts were prepared by coprecipitation from the nitrates of metal components followed by calcination to mixed oxides at 550 °C. A part of Mg2+ in Mg 3Fe0.5Al0.5 mixed oxide was replaced with Zn2+ to test the effect of MgO as the support. The mixed oxides were composed of periclase and spinel-type compounds with a high surface area of 100-180m2gcat-1. Mössbauer and XPS measurements indicated the presence of Fe3+ on the catalysts and H2-TPR measurement suggested that the dehydrogenation reaction is catalyzed by the reduction-oxidation between Fe3+/Fe2+. The activity of Mg3-xZnxFe0.5Al0.5 mixed oxide decreased with increasing x, indicating an important role of MgO on the activity. Both CO2-TPD measurements as well as IR measurements of adsorbed CO2 clearly indicated the presence of basic sites of Mg 2+O2- on the catalysts. It seems that the combination of Mg2+O2- and Fe3+ was essential for the catalytic activity. It is concluded that the surface base sites generated on O2- bound Mg2+ near Fe3+ sites are responsible for H+-abstraction; the dehydrogenation of ethylbenzene was initiated by the H+ abstraction on Mg2+O2- basic sites, and accelerated by the reduction-oxidation of Fe3+/Fe2+ active species. © 2011 Elsevier B.V.
Citation:
Balasamy RJ, Tope BB, Khurshid A, Al-Ali AAS, Atanda LA, et al. (2011) Ethylbenzene dehydrogenation over FeOx/(Mg,Zn)(Al)O catalysts derived from hydrotalcites: Role of MgO as basic sites. Applied Catalysis A: General 398: 113–122. Available: http://dx.doi.org/10.1016/j.apcata.2011.03.023.
Publisher:
Elsevier BV
Journal:
Applied Catalysis A: General
Issue Date:
May-2011
DOI:
10.1016/j.apcata.2011.03.023
Type:
Article
ISSN:
0926-860X
Sponsors:
This publication was based on the work supported by Award No. K-C1-019-12 made by King Abdullah University of Science and Technology (KAUST). The support of King Fahd University of Petroleum and Minerals (KFUPM) is also highly appreciated. The authors are grateful to Prof. Emeritus H. Hattori of Hokkaido University for helpful discussions. The authors also acknowledged Japan Cooperation Center, Petroleum (JCCP) for giving an opportunity of this collaborative research.
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DC FieldValue Language
dc.contributor.authorBalasamy, Rabindran J.en
dc.contributor.authorTope, Balkrishna B.en
dc.contributor.authorKhurshid, Alamen
dc.contributor.authorAl-Ali, Ali A Sen
dc.contributor.authorAtanda, Luqman A.en
dc.contributor.authorSagata, Kunimasaen
dc.contributor.authorAsamoto, Makikoen
dc.contributor.authorYahiro, Hidenorien
dc.contributor.authorNomura, Kiyoshien
dc.contributor.authorSano, Tsunejien
dc.contributor.authorTakehira, Katsuomien
dc.contributor.authorAl-Khattaf, Sulaiman S.en
dc.date.accessioned2016-02-28T07:58:55Zen
dc.date.available2016-02-28T07:58:55Zen
dc.date.issued2011-05en
dc.identifier.citationBalasamy RJ, Tope BB, Khurshid A, Al-Ali AAS, Atanda LA, et al. (2011) Ethylbenzene dehydrogenation over FeOx/(Mg,Zn)(Al)O catalysts derived from hydrotalcites: Role of MgO as basic sites. Applied Catalysis A: General 398: 113–122. Available: http://dx.doi.org/10.1016/j.apcata.2011.03.023.en
dc.identifier.issn0926-860Xen
dc.identifier.doi10.1016/j.apcata.2011.03.023en
dc.identifier.urihttp://hdl.handle.net/10754/600103en
dc.description.abstractA series of Mg3-xZnxFe0.5Al0.5 mixed oxide catalysts derived from hydrotalcites were tested in the ethylbenzene dehydrogenation to styrene in He atmosphere at 550 °C. The catalysts were prepared by coprecipitation from the nitrates of metal components followed by calcination to mixed oxides at 550 °C. A part of Mg2+ in Mg 3Fe0.5Al0.5 mixed oxide was replaced with Zn2+ to test the effect of MgO as the support. The mixed oxides were composed of periclase and spinel-type compounds with a high surface area of 100-180m2gcat-1. Mössbauer and XPS measurements indicated the presence of Fe3+ on the catalysts and H2-TPR measurement suggested that the dehydrogenation reaction is catalyzed by the reduction-oxidation between Fe3+/Fe2+. The activity of Mg3-xZnxFe0.5Al0.5 mixed oxide decreased with increasing x, indicating an important role of MgO on the activity. Both CO2-TPD measurements as well as IR measurements of adsorbed CO2 clearly indicated the presence of basic sites of Mg 2+O2- on the catalysts. It seems that the combination of Mg2+O2- and Fe3+ was essential for the catalytic activity. It is concluded that the surface base sites generated on O2- bound Mg2+ near Fe3+ sites are responsible for H+-abstraction; the dehydrogenation of ethylbenzene was initiated by the H+ abstraction on Mg2+O2- basic sites, and accelerated by the reduction-oxidation of Fe3+/Fe2+ active species. © 2011 Elsevier B.V.en
dc.description.sponsorshipThis publication was based on the work supported by Award No. K-C1-019-12 made by King Abdullah University of Science and Technology (KAUST). The support of King Fahd University of Petroleum and Minerals (KFUPM) is also highly appreciated. The authors are grateful to Prof. Emeritus H. Hattori of Hokkaido University for helpful discussions. The authors also acknowledged Japan Cooperation Center, Petroleum (JCCP) for giving an opportunity of this collaborative research.en
dc.publisherElsevier BVen
dc.subjectEthylbenzene dehydrogenationen
dc.subjectFeOx/(Mg,Zn)(Al)O catalystsen
dc.subjectH+ abstractionen
dc.subjectMg2+O2- base supporten
dc.subjectStyreneen
dc.titleEthylbenzene dehydrogenation over FeOx/(Mg,Zn)(Al)O catalysts derived from hydrotalcites: Role of MgO as basic sitesen
dc.typeArticleen
dc.identifier.journalApplied Catalysis A: Generalen
dc.contributor.institutionDepartment of Materials Science and Biotechnology, Graduate School of Science and Engineering, Ehime University, Matsuyama 790-8577, Japanen
dc.contributor.institutionSchool of Engineering, University of Tokyo, Hongo 7-3-1, Bunkyoku, Tokyo 113-8656, Japanen
dc.contributor.institutionDepartment of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Kagamiyama, 1-4-1, Higashi-Hiroshima 739-8527, Japanen
kaust.authorBalasamy, Rabindran J.en
kaust.authorTope, Balkrishna B.en
kaust.authorKhurshid, Alamen
kaust.authorAl-Ali, Ali A.S.en
kaust.authorAtanda, Luqman A.en
kaust.authorTakehira, Katsuomien
kaust.authorAl-Khattaf, Sulaiman S.en
kaust.grant.fundedcenterKAUST Center In Development at KFUPMen
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