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SUMMARY:Intermetallic Compounds – Materials for a  Knowledge-Based Devel
 opment in Heterogeneous Catalysis - M. Armbrüster\, Max-Planck-Institute 
 for Chemical Physics of Solids\, Nöthnitzer Str. 40\, 01187 Dresden\, Ger
 many
DTSTART:20111111T150000Z
DTEND:20111111T160000Z
UID:TALK34091@talks.cam.ac.uk
CONTACT:Caterina Ducati
DESCRIPTION:Development  in  heterogeneous  catalysis  is  often  hindered
   by  the  complexity of  the  applied  catalytic systems. While this is n
 ecessary for industrial use to maximise the surface area and stability\, a
  valuable basic science approach is to make the catalysts “as simple as 
 possible\, but not simpler” (A. Einstein). \nA  class  of  compounds  no
 t  often  investigated  in  catalysis  are  intermetallic  compounds\,  wh
 ich  differ \nstrongly  from  substitutional  alloys\,  since  they  posse
 ss  crystal  structures  different  from  the  constituent elements. [1]  
 The more complicated structures – extreme cases are quasicrystalline com
 pounds\, the discovery of which has been awarded the Noble price in chemis
 try 2011 – result from the partly covalent bonding within the compounds\
 , which also enhances their stability leading to high stability under reac
 tion conditions and reduced segregation. The structural changes and the bo
 nding situation result in much stronger changes of the electronic structur
 e compared to substitutional alloys. \n\nCombining the “as simple as pos
 sible\, but not simpler” idea with the huge potential of the intermetall
 ic \ncompounds  leads  to  their  unsupported  use  in  heterogeneous  cat
 alysis.  Due  to  their  large  number  (more than 10\,000 binary intermet
 allic compounds are known and many more with more than two elements) this 
 \nopens a vast matrix to explore relationships between electronic and crys
 tal structure on the one hand and \nthe catalytic properties on the other.
  Uncovering these relationships leads to a deep understanding and the \nga
 ined  knowledge  can  be  used  to  select  intermetallic  compounds  with
   optimised  crystal  and  electronic structure  in  the  next  step.  Thi
 s  approach  leads  to  a  knowledge-based  development  and  is  named  t
 he \nknowledge-based approach. [2]   \nThis  approach  has  been  successf
 ully  applied  in  the  development  of  a  new  class  of  highly  select
 ive semi-hydrogenation  catalysts  based  on  Ga-Pd  intermetallic  compou
 nds.  These  compounds  represent the first  example\,  where  the  knowle
 dge-based  approach  was  applied  starting  from  the  bulk  materials\, 
 [2-5]  \nstudying their stability under reaction conditions\, [5\,6]  deve
 loping an approach to unsupported nanoparticu-\nlate materials [7]  and in
 venting an industrially feasible route to highly active materials while pr
 eserving the \nselectivity and stability of the bulk compounds. [8]  Due t
 o the knowledge gained during the investigations\, \nthe Pd-based systems 
 could finally be replaced by more ubiquitous non-noble metal based materia
 ls. [9]  \n\n[1]      H. Kohlmann\, in Encycl. of Physical Science and Tec
 hnology\, 3 rd  ed.\, Vol. 9\, 2002\, Academic Press. \n\n[2]      K. Kovn
 ir\, M. Armbrüster\, D. Teschner\, T.V. Venkov\, F.C. Jentoft\, A. Knop-G
 ericke\, Yu. Grin\, R. Schlögl\, \nSci. Technol. Adv. Mater. 8\, 2007\, 4
 20. \n\n[3]      J. Osswald\, K. Kovnir\, M. Armbrüster\, R. Giedigkeit\,
  R.E. Jentoft\, U. Wild\, Yu. Grin\, R. Schlögl\, J. Catal. \n258\, 2008\
 , 219. \n\n[4]      K. Kovnir\, J. Osswald\, M. Armbrüster\, R. Giedigkei
 t\, T. Ressler\, Yu. Grin\, R. Schlögl\, Stud. Surf. Sci. Catal. \n162\, 
 2006\, 481. \n\n[5]      M. Armbrüster\, K. Kovnir\, M. Behrens\, D. Tesc
 hner\, Yu. Grin\, R. Schlögl\, J. Am. Chem. Soc. 132\, 2010\, 14745-14747
 . \n\n[6]      J. Osswald\, R. Giedigkeit\, R.E. Jentoft\, M. Armbrüster\
 , F. Girgsdies\, K. Kovnir\, T. Ressler\, Yu. Grin\, R. Schlögl\, J. Cata
 l. 258\, 2008\, 210. \n\n\n[7]      K. Kovnir\, M. Armbrüster\, D. Teschn
 er\, T.V. Venkov\, L. Szentmiklósi\, F.C. Jentoft\, A. Knop-Gericke\, Yu.
  \nGrin\, R. Schlögl\, Surf. Sci. 603\, 2009\, 1784. \n\n[8]      M. Armb
 rüster\, G. Wowsnick\, M. Friedrich\, M. Heggen\, R. Cardoso-Gil\, J. Am.
  Chem. Soc. 133\, 2011\, 9112. \n\n[9]      A. Ota\, M. Armbrüster\, M. B
 ehrens\, D. Rosenthal\, M. Friedrich\, I. Kasatkin\, F. Girgsdies\, W. Zha
 ng\, R. \nWagner\, R. Schlögl\, J. Phys. Chem. C 115\, 2011\, 1368. \n\n[
 10]    M. Armbrüster\, K. Kovnir\, Yu. Grin\, R. Schlögl\, P. Gille\, M.
  Heggen\, M. Feuerbacher\, PCT/EP2010/053682\, \n2010. 
LOCATION:T001 [Tower Seminar Room]\, Materials Science and Metallurgy\, De
 partment of
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