A miniature catalytic reactor has been developed for the oxidation of alcohols with O-2 in supercritical CO2. Particular attention has been given to ensuring good mixing of O-2 and CO2 prior to contact with the substrate. The reactor was optimised using the oxidation of 2-octanol over 5% Pt + 1% Bi on Al2O3 and the mass balance was measured. The reactor was then evaluated for the oxidation of a series of secondary alcohols, and also the primary alcohol, 1-octanol.