The kinetic features of ethylbenzene (RH) oxidation and alpha-phenylethyl hydroperoxide (ROOH) degradation in the presence of the cationic surfactant cetyltrimethylammonium bromide (CTAB) and bis(acetylacetonato)cobalt(II) (Co(acac)(2)) were studied. The combination of Co(acac)(2) (0.1 mM) with CTAB (1 mM) makes an effective, synergistic catalytic system: the oxidation of RH at 60 degreesC is characterized by a high O-2 uptake rate and a low steady-state concentration of ROOH the main RH oxidation product in this system is acetophenone. The apparent activation energy of ROOH degradation is E-ap = 45.5 kJ/mol, and the yield of radical is e = 0.09. It is assumed that, in ethylbenzene oxidation with air, the cobalt-bromide catalysis mechanism is operative in the CTAB- Co(acac)(2) system; the concentration of reactants (ROOH, Co(II), Br-) in CTAB microaggregates at a small total catalyst concentration increases the ROOH degradation rate and decreases the yield of radicals escaping to the bulk of the hydrocarbon.