Local chemical properties of nanostructured Au-Pd bimetal model catalysts

Abstract

The local chemical properties of specific sites on bimetallic Au-Pd(111) surfaces are investigated in a combined STM, HREELS, and TPD study. Growth and alloying processes are analysed on the atomic scale using STM. From atomically resolved STM images precise information on the structure and composition of bimetallic Au-Pd(111) surfaces is obtained. The adsorption behaviour of carbon monoxide and ethylene on these well-defined bimetallic surfaces is analysed using HREELS and TPD. The combination of STM, HREELS, and TPD in one UHV chamber allows to determine the chemical properties of sites like Au island edge atoms, Pd atoms in a Au matrix (Pd monomers), or Pd dimers in a Au matrix.