Metal-metal and metal-support interaction on Rh+Co/Al2O3 prepared by co-impregnation and Rh2Co2/Al2O3 by using RhCo carbonyl cluster as the precusor have been studied in detail by X-ray Photoelectron Spectroscopy (XPS). It was found that binding energy for Rh 3d on Rh+Co/Al2O3 reduced with H2 at 400℃ is nearly identical with that of Rh^0, and Co exists essentially in CoAl2O4 state and only the very small amount of Co exists as Co^0. On Rh2CO2/Al2O3 reduced with H2 at 400℃ Rh exists as Rh^0, and a part of Co exists in CoAl2O4 state whereas another part of Co exists as Co^0. Results above indicate that Rh-Al2O3 interaction for Rh+Co/Al2O3 and Rh2Co2/Al2O3 is weak, and Co- Al2O3 interaction is strong; Rh-Co interaction on Rh+Co/Al2O3 prepared by coimpregnation of RhCl3 and Co(NO3)2 is weak, but on Rh2CO2/Al2O3 prepared by using RhCo carbonyl cluster as the precusor the strong Rh- Co interaction of RhCo carbonyl cluster is still maintained resulting in the considerable amount of Co^0.

Key words: COBALT, METAL CATALYST, ALUMINIUM OXIDE, CARRIERS, X-RAY PHOTOELECTRON SPECTROMETRY, RHODIUM, INTERACTIONS