The catalytic activities of 5,10,15,20-meso-tetraphenylporphyrinatechloroiron(III), [Fe(TPP)Cl], and 5,10,15,20-meso-tetraphenylporphyrinatechloroiron(III) encapsulated in zeolite Y, [Fe-III(TPP)Y], were investigated using cyclohexane as substrate in supercritical carbon dioxide (scCO(2)), using either tert-butyl-hydroperoxide (t-BuOOH) or hydrogen peroxide (H2O2) as terminal oxidants. Using [Fe(TPP)Cl], in 2 h, at 0.724 g cm(-3), were obtained conversions of up to 26 turnover per hour. The selectivity with [Fe(TPP)Cl] was higher in scCO(2) than in organic solvents, of up to 15% cyclohexanol production. Lower conversions were observed with the "ship in a bottle" catalyst, [Fe(TPP)Y]. (c) 2004 Elsevier B.V. All rights reserved.