66-6 FIELD Section Title:Surface Chemistry and Colloids 78 Laboratoire de Reactivite de Surface, UPMC University of Paris, Paris, Fr. FIELD URL: written in English ; The interaction of gold particles with a silica surface is investigated using a combination of theor. and exptl. techniques. It is found that the physisorption strength of gold on silica decreases with increasing chloride concn. at the surface, with increasing cluster size, and with decreasing oxidn. state of gold. However, the gold precursor is adsorbed more strongly than the corresponding precursor fragments and this via an H-bond network. It is also found that chemisorbed, grafted species may coexist on a silica surface, depending on the exptl. conditions. From the vibrational frequencies and esp. by the presence of a band at 3650 cm-1, it is found that the gold species after calcination are probably present under the form of digrafted chemisorbed species. This information enables us to propose a scenario for the formation of gold clusters at the silica surface. [on SciFinder(R)]