ARGONNE NATIONAL LABORATORY

CHEMICAL SCIENCES AND ENGINEERING DIVISION

 

SPEAKER:     Professor Dr. H.-J. Freund

                          Fritz-Haber-Institut

 

TITLE:             Ultra-thin Oxide films as designable Model Catalysts

 

TIME:              2:00 pm

 

DATE:              Friday, March 21, 2008

                         

PLACE:           Building 200, J-183

 

HOST:              Julius Jellinek

 

Abstract: Low-temperature STM measurements combined with DFT calculations are employed to analyze the adsorption of gold on alumina/NiAl(110). The binding of Au monomers involves breaking of an oxide Al-O bond below the adatom and stabilizing the hence under-coordinated O ion by forming a new bond to an Al atom in the NiAl. The adsorption implies negative charging of the adatom. The linear arrangement of favorable binding sites induces the self-organization of Au atoms into chains. For every ad-chain, the number of electrons, in particular of transfer-electrons from the support, is determined by analyzing the node structure of its HOMO