FTIR CHARACTERIZATION OF RE-2(CO)(10) ADSORBED ON SULFATED ZIRCONIUM DIOXIDE

The interaction of Re-2(CO)(10) with highly dehydroxylated sulfated zi rconia has been studied by in situ FTIR spectroscopy. Adsorption at ro om temperature leads to the formation of O-bonded surface adducts, whe re an axial CO ligand of the metal carbonyl is coordinated to a Zr4+ i on at the oxide surface. Two sets of IR absorption bands were observed in the carbonyl stretching region. These were assigned to Re-2(CO)(10 ) inter-acting with two types of surface sites of different Lewis acid strength. In addition, physically adsorbed Re-2(CO)(10) was also obse rved. Upon heating at 373 K, the carbonyl (both physically and chemica lly adsorbed) moves to surface sites with higher Lewis acid strength. (C) 1997 Elsevier Science Ltd.