And a little bit of ceria''' The Promoting Effect of Ceria on Silver Selective Oxidation Catalysis

1
And a little bit of ceria...The Promoting Effect
of Ceria on Silver Selective Oxidation Catalysis
Matthias J. Beier
Supervisors Jan-Dierk Grunwaldt
Georgios Kontogeorgis Supported by Haldor
Topsøe A/S, DTU-KT, MP2T (and FTP project)
2
The Impact of Selective Oxidation Catalysis

• Selective Oxidation Highly important for the
  production of key intermediates
• Challenges
• Overoxidation/ Selectivity
• Activity
• Inexpensive catalyst
• Inexpensive oxidizing agent, i.e. oxygen

3
The selective oxidation of alcohols to aldehydes
in the liquid phase

• Useful in the fine chemical synthesis of
  odorants, artificial flavors and drugs
• Upgrading of biomass platform molecules
• Most catalysts based on Au, Pd, Pt and Ru in the
  liquid phase

4
Searching for active silver catalysts

• Screening of supported silver catalysts with a
  test reaction

A physical mixture of Ag/SiO2 and nano CeO2 is
active!
M.J. Beier, T.W. Hansen, J.-D. Grunwaldt, J.
Catal. 2009, 266, 320.
5
Catalyst performance
Conditions 20 mL xylene, 0.10 g biphenyl, 2.00
mmol benzyl alcohol, 50 mg catalyst, (25 mg
CeO2), 2 h reflux in O2 atmosphere.
6
The collaborative effect of silver and ceria
Silver activates the alcohol
Ceria activates oxygen
M.J. Beier, T.W. Hansen, J.-D. Grunwaldt, J.
Catal. 2009, 266, 320.
7
CeO2 as promoter for Ag, Au and Pd catalysts in
the selective alcohol oxidation
Without CeO2
With CeO2
Conditions 20 mL xylene, 0.10 g biphenyl, 2.00
mmol benzyl alcohol, 50 mg catalyst, (25 mg
CeO2), 2 h reflux in O2 atmosphere.
? Ceria promotes catalyst activity and
selectivity in all cases
8
Summary and Outlook

• Ag/SiO2 becomes an effective catalyst for
  alcohol oxidation by adding nanocrystalline
  CeO2
• CeO2 has a general promoting effect
• Ag/CeO2-SiO2 is also capable of promoting the
  oxidation of more inert aryl aromatic compounds

9
Thanks to Jan-Dierk Grunwaldt Georgios
Kontogeorgis Søren Mikkelsen KT
technicians Haldor Topsøe A/S
Thanks for the Attention !