Gas-phase deposition and thermal transformations of Cr(acac)(3) on the surface of alumina supports

Gas-phase deposition and subsequent thermal activation of Cr(acac)(3) on the surface of fumed and precipitated alumina supports have been studied by diffuse reflectance FTIR spectroscopy, TG-DTG, TPO and chemical analysis. It has been found that stabilisation of Cr(acac)(3) on alumina occurs in a molecular form owing to the donor-acceptor interaction of the acetylacetonate ligands with surface hydroxy groups and coordinatively unsaturated Al3+ ions. Thermally activated processes of removal of acetylacetonate ligands assisted by proton transfer and acetylacetonate ligand pyrolysis have been discriminated.