Dipl.-Chem. Johannes Schaeffer - LCVT

Prof. Dr. Andreas Jess, Department of Chemical Engineering at the University of Bayreuth, in the future of his science, ethics and the question of how much earth needs man. Only available in german language.
Graduates in demand, which may be part of a diploma or PhD thesis in the context of an industrial cooperation are want to deal with various problems of chemical engineering. If you are interested please contact us immediately to get information about current offers.
Together with Peter Wasserscheid from the chair of chemical reaction engineering at the university of Erlangen/Nuremberg Andreas Jess published the textbook "Chemical technology - An Integrated Textbook" in february 2013.

Dipl.-Chem. Johannes SchäfferSchäffer

Staff scientist


since 01.10.2013

 

 

 

 

Research topics:

  • Ionic liquids (ILs) in catalysis
  • Micellar-catalytic epoxidation of cyclooctene using ionic liquids

   

Epoxidation is an important step in the valorisation of olefins since epoxides are highly useful as intermediates for the manufacture of high-value industrial products. In industry, not only ethylene oxide and propylene oxide, but also epoxides derived from longer-chain olefins are of interest, e.g. as reactive diluents, plasticisers or as reactants for fine chemicals production [1]. During epoxidation of these olefins, H2O2, which is a commonly employed oxidant, is in the aqueous phase while the hydrophobic olefins form a second organic phase. The low solubility of olefins in the aqueous phase and that of the oxidant in the organic phase limit the overall reactivity. Thus the choice of an appropriate catalytic and solvent system is crucial to attain satisfactory catalytic activity. Phase transfer catalysis is a conventional approach to tackle this issue [2, 3]. Alternatively, micellar catalytic systems that improve catalyst or substrate solubility by micelle formation in the aqueous phase can lead to higher catalytic activity [4]. In 2013, Markovits et al. reported for the first time that the catalytically inactive perrhenate anion gains largely in activity for epoxidation of cyclooctene with hydrogen peroxide when used as anion in an imidazolium-based ionic liquid [5, 6]. Our focus is on the mechanistic and kinetic description of the perrhenate-catalysed epoxidation and on its possible industrial implementation.

  

[1] G. Sienel, R. Rieth, K. Rowbottom: Epoxides, in: Ullmann’s Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2012.
[2] E. V. Dehmlow, S. S. Dehmlow, Phase Transfer Catalysis, Wiley-VCH, Weinheim, 1993.
[3] S.-S. Wang, G.-Y. Yang, Chem. Rev. 2015, 115, 4893-4962.
[4] J. H. M. Heijnen et al., Chem. Eng. Proc. 2003, 42, 223-230.
[5] I. I. E. Markovits et al., Chem. Eur. J. 2013, 19, 5972-5979.
[6] M. Cokoja et al., ChemSusChem 2016, 9, 1773-1776.


Phone:+ 49 (0) 921 / 55 - 7438
Fax:+ 49 (0) 921 / 55 - 7435
E-Mail: johannes.schaeffer@uni-bayreuth.de
Room: A 1.08