In the article  research results of formation capability of active surface Co–Mn/Al₂O₃/Al-frame catalysts for liquid phase oxidations xylenes in conditions of heat treatment of samples in an electromagnetic field  of  microwave – range are submitted. It has been determined that more intensive absorption  of microwave  radiation energy and it’s transformation in heat at stage of formation oxides of active  metals takes place in case g-Al₂O₃/Al  samples tnat  impregnated with a mix of nitrates of  cobalt and manganese  thane their individual salts. And  spontaneous temperature rise samples  from 400 till 727 K obtains at formation of the  manganese cobaltite  phase. The received results are suggested that generation of active Co–Mn/Al₂O₃/Al catalysts surface for liquid-phase oxidation in SHF thermal treatment is reasonable for practical realization and it has more good differ from traditional thermal actions through synthesis time saving