Co-TUD-1, (Cobalt-Technische Universiteit Delft-1), an amorphous sponge-like mesoporous cobalt-contg. silicate, is active and selective catalyst for the aerobic oxidn. of cyclohexane. The decompn. of cyclohexyl hydroperoxide (CHHP) was carried out over Co-TUD-1, with complete conversion of CHHP and excellent selectivity towards cyclohexanol and cyclohexanone. The catalyst showed stable activity over a period of one week obsd. in rigorous leaching expts. during the continuous decompn. of CHHP. No leaching of metal was detected, proving the catalyst to be truly heterogeneous. [on SciFinder(R)]