An improved process for the preparation of adipic acid

The present invention relates to an improved process for the preparation of adipic acid. More particularly, the present invention relates to an environmental-friendly, clean process for the preparation of adipic acid through oxidation of cycloyhexanol, cyclohexanone or a mixture thereof with oxygen or oxygen-containing gas, in the presence of an oxidation initiator, a polar solvent and an organometallic µ3-oxo-bridged Co/Mn cluster complex catalyst.