Talk

Friday, May 22nd, 2015

Speaker
Ioannis Lykakis
Affiliation
Department of Chemistry, Aristotle University of Thessaloniki, Greece
Title
Organic transformations catalyzed by supported noble metal nanoparticles and polyoxometalates
Location
Dept. of Mathematics Bldg., Voutes, Room A210 (close to main entrance)
Time
16:00
Language
English
Abstract

For catalytic processes, an attractive approach is the use of a solid, recyclable catalyst and environmentally friendly reagents. The use of supported catalysts on a well ordered metal oxide surface for heterogeneous catalysis offers several advantages on the catalyst reusability and the regio- and chemo-selectivity of the reaction process. Thus, herein we outline a research study aimed to gain insight into the catalytic applications of new AuNPs and AgNPs heterogeneous systems,1 as well as supported polyoxometalates2 in order to afford new catalytic chemical transformations, based on the combination of metal nanoparticles and the surface of the support properties.1-4 For this reason, the catalytic reduction of nitro aromatic compounds by AuNPs or AgNPs supported catalysts using NaBH4 and 1,1,3,3-tetramethyldisiloxane (TMDS) as hydrogen donor molecules5 and the selective oxidation of aryl amines into nitrosoarenes with H2O2 catalyzed by Au/TiO2 were studied. In parallel, the general applicability and the mechanistic approach of the selective photooxidation of various benzyl alcohols into the corresponding carbonyl compounds, over mesoporous CdS or POM-TiO2 assemblies, using O2 as "green" oxidant were also studied.6,3 Finally, detail mechanistic studies based on kinetic isotope effects, on Hammett type-kinetics and product analysis were performed.

References

  1. (a) Mitsudome, T.; Kaneda, K. Green Chem. 2013, 15, 2636; (b) Stratakis, M.; Garcia, H. Chem. Rev. 2012, 112, 4469; (c) Zhang, Y.; Cui, X.; Shi, F.; Deng, Y. Chem. Rev. 2012, 112, 2467.
  2. Hill, C. L., (Ed.) Chem. Rev., 1998, 98, 1; J. Mol. Catal. A: Chem., 2007, 262, 1.
  3. Tzirakis, M. D.; Lykakis, I. N.; Orfanopoulos, M. Chem. Soc. Rev., 2009, 38, 2609.
  4. Corma, A.; Serna, P. Science 2006, 313, 332.
  5. (a) Tamiolakis, I.; Fountoulaki, S.; Vordos, N.; Lykakis, I. N.; Armatas, G. S. J. Mater. Chem. A, 2013, 1, 14311; (b) Fountoulaki, S.; Daikopoulou, V.; Gkizis, P. L.; Tamiolakis, I.; Armatas, G. S.; Lykakis, I. N. ACS Catalysis, 2014, 4, 3504.
  6. Tamiolakis, I.; Lykakis, I. N.; Katsoulidis, A. P.; Armatas, G. S.; Chem. Commun., 2012, 48, 6687.

See text.