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

Abstract

The catalytic properties of sp²- and sp³-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. sp² carbons showed the higher activity than sp³ carbons. The highest activity was obtained over mesoporous graphene, a representative sp²-hybridized carbon, yielding a weight-normalized activity of 162.6 mmol g⁻¹ h⁻¹. The excellent performance of sp² 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.