Fritz-Haber-Institut der Max-Planck-Gesellschaft  

Inorganic Chemistry – Reactivity Group
  

   Search:          AC   CP   MP   PC   TH   MPG   
Electrochemistry Group:
Sébastien Cap
 
Research
Methods
Highlights
Publications
Teaching
Group Members
Open Positions
Services
 
Research Topic:
  Interfacial charge transport in oxidation catalysts for the selective oxidation of ethane, propane and n-butane
Anna Maria Wernbacher

Selective oxidation catalysis will be playing a crucial role in the ambitious goal of replacing the crude-oil based raw materials of today`s petro-chemical industry by more sustainable, ideally renewable resources. One of the key challenges is the efficient and direct functionalization of alkanes from natural gas or future regenerative carbon-based feedstocks. However, a major breakthrough in this field is still impeded by the lack of suitable catalysts and the absence of a detailed mechanistic understanding of the few efficient alkane oxidation reactions.



(to see full size, click on the image)


The so far only industrially applied selective alkane oxidation reaction is the oxidation of n-butane (C4) to maleic anhydride (MA) on vanadyl pyrophosphate (VPP) catalysts, though the achieved MA yield of about 60% still shows potential for improvement. The direct oxidation of propane to acrylic acid (AA) on the M1 phase of the polynary transiton metal oxide MoVTeNbOx is with optimized AA yields of 50% still awaiting its commercial breakthrough. Though the oxidative dehydrogenation (ODH) of ethane over the same catalyst exhibits ethylene yields in the range of 70%, this process is still economically unfavourable in comparison to steam-cracking, not to mention the either very low yields or very harsh conditions needed for the selective oxidation of methane to valuable products. Due to the rather high amount of charge carriers formally transferred in a catalytic redox cycle (e.g. 14 electrons from C4 to MA), it is still controversially debated if such oxidation reactions can be explained just on the basis of the single site concept with an isolated active center large enough to “store” reversibly the high charge carrier number, or if (and how) subsurface layers with appropriate charge transfer properties have to be taken into account.
 
References
  1. M. Eichelbaum, et al.,
    Phys. Chem. Chem. Phys 2012, 14, 1302-1312.
  2. M. Eichelbaum, et al.,
    Angewandte Chemie, International Edition 2012, 51, 6246–6250.
  3. C. Heine, et al.,
    Applied Physics A 2013, 112, 289-296.
  4. M. Eichelbaum, et al.,
    ChemCatChem 2013, 5, 2318–2329.
   Impressum • © FHI - AC
   Webmaster: Olaf Trunschke
Address: Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany    
Abteilung Anorganische Chemie - Direktor Prof. Dr. Robert Schlögl    
Tel: +49 30 8413 4404, Fax: +49 30 8413 4401, E-Mail: acsek@fhi-berlin.mpg.de