XVIth International Workshop on
Quantum Systems in
Chemistry and Physics
QSCP logo Abstract
 Main | Registration | Abstract Submission | List of Registrants | List of Abstracts | Program 
Accommodation | Location and Access | Previous Workshops | ISTCP-VII | Photos
Oral presentations only. Posters only. Show all.

Theoretical investigation of the hetero-junction effect in polymer stabilized precious metal clsuters
Mitsutaka Okumura,1,2 Yasutaka Kitagawa,1 Takashi Kawakamai,1and Shushuke Yamanaka1
1Department of Chemistry, Graduate School of Science, Osaka University, Japan

2Core Research for Evaluational Science and Technology, Japan
In recent years, gold is attracting industrial and scientific interests for its catalytic activity in such reactions as propylene partial oxidation, odor decomposition H2O2 direct production and CO oxidation at low temperatures, especially when Au is deposited as nanoparticles on selected metal oxides. Highly dispersed gold catalysts exhibit unique catalytic features in low-temperature CO oxidation. In this reaction, the use of oxides of several 3d transition metals and the hydroxides of alkaline earth metals as supports leads to high activities even at a temperature as low as 203 K.
Lately, Tsukuda has found that the Au nanoclusters stabilized by poly(N-Vinyl-2-pyrrolidone) [PVP; (C6H9ON)n] , abbreviated as Au:PVP, can oxidize p-hydroxybenzyl alcohol selectively into the corresponding aldehyde in water without degradation.
This observation indicates that Au cluster can exhibit high catalytic activity without any metal oxide supports. Therefore, the interaction (hetero-junction) between Au cluster and PVP seems to be an important factor to oxidize benzylic alcohols to the corresponding aldehyde over the Au:PVP catalyst.
These results suggest that the hetero-junctions, such as metal cluster-support junctions in heterogeneous catalysts, metal-ligands junctions in metal complex, active sites in enzymes, metal cluster-stabilizer junction in the polymer stabilized clusters and etc., are the key factors to promote and/or modify the catalytic reaction over several types of catalysts. Therefore, we have carried out hybrid density functional theory (DFT) calculations on the hetero-junction effect between Au clusters and PVP. The present theoretical study has been undertaken to explain the hetero-junction effect between PVP molecules and Au clusters as a first step for understanding the hetero-junction effect of the catalytic reactions over the polymer stabilized Au nanoclusters.


 Main | Registration | Abstract Submission | List of Registrants | List of Abstracts | Program 
Accommodation | Location and Access | Previous Workshops | ISTCP-VII | Photos