sp2- and sp3 -hybridized carbon materials as catalysts for aerobic oxidation of cyclohexane

The catalytic properties of sp(2)- and sp(3)- hybridized carbons, represented by graphene and diamond, in the selective oxidation of cyclohexane were investigated to understand the structure dependence of carbon materials in the reaction. sp(2) carbons showed the higher activity than sp(3) carbons. The highest activity was obtained over mesoporous graphene, a representative sp(2)-hybridized carbon, yielding a weight-normalized activity of 162.6 mmol g(-1) h(-1). The excellent performance of sp(2) carbons was rationalized by their ability to catalyze the decomposition of peroxide intermediates, such as cyclohexyl hydroperoxide, which promoted the oxidative reaction to produce cyclohexanol and cyclohexanone.