Investigation of the electronic interaction between TiO2(110) surfaces and Au clusters by PES and STM

• Published in: Surface science Vol. 566-568; no. 2; pp. 1012 - 1017
• Main Authors: Minato, T, Susaki, T, Shiraki, S, Kato, H S, Kawai, M, Aika, K-i
• Format: Journal Article
• Language: English
• Published: 20.09.2004
• ISSN: 0039-6028
• DOI: 10.1016/j.susc.2004.06.047

Catalytic activity of gold clusters appears for the size of 2-3 nm and the origin of this catalytic activity is still controversial. TiO2 is one of the best supports for Au catalyst. The electronic interaction between TiO2(110) surfaces and Au clusters has been investigated by photoelectron spectroscopy (PES) and scanning tunneling microscopy (STM) to elucidate the high catalytic activity of Au/TiO2. With increasing Au amount, the shift of 0 2p nonbonding peak towards the Fermi level and the decrease in the Ti 3d peak area were precisely observed in the valence band PES spectra of Au/TiO2(1 1 0). These changes in the valence band structure are attributed to the electron transfer from the surface defects on TiO2(1 1 0) into the Au clusters. At the low coverage region, the STM images consistently show that the Au clusters nucleate at the surface defects of TiO2(1 1 0). Here, we discuss the electronic interaction between the Au clusters and the TiO2 surface relating to the catalytic activity of Au clusters on surfaces.