Selective oxidation of cyclohexane to cyclohexanol/ cyclohexanone (KA−oil) is an important chemical process, which is still constrained by low conversion and selectivity and high energy consumption. In this study, Cu-doped mesoporous TiO 2 (Cu-MT) has been successfully synthesized via calcinating MIL-125(Ti) doped with copper acetylacetonate, which shows high reactivity in selective oxidation of cyclohexane to KA−oil by persulfate (PS) with the desirable cyclohexane conversion of 16.8% and a selectivity of 98.0% under mild conditions and the low ratio of PS/cyclohexane of 1:1. A series of characterizations and density functional theory calculations reveal that the doped Cu(I,II) on Cu-MT is the reactive site for non-radical activation of PS with the moderate elongation of the O−O bond in PS, which then abstracts 1H (1H + + 1e − ) from cyclohexane to form Cy • and eventually KA−oil. This study gives new insight on the importance of moderately activated PS in selective oxidation of C−H.