Mechanistic insight into the catalytic oxidation of cyclohexane over carbon nanotubes: kinetic and in situ spectroscopic evidence

Abstract

As some of the most interesting metal-free catalysts, carbon nanotubes (CNTs) and other carbon-based nanomaterials show great promise for some important chemical reactions, such as the selective oxidation of cyclohexane (C6H12). Due to the lack of fundamental understanding of carbon catalysis in liquid-phase reactions, we have sought to unravel the role of CNTs in the catalytic oxidation of C6H12 through a combination of kinetic analysis, in situ spectroscopy, and density functional theory. The catalytic effect of CNTs originates from a weak interaction between radicals and their graphene skeletons, which confines the radicals around their surfaces. This, in turn, enhances the electron-transfer catalysis of peroxides to yield the corresponding alcohol and ketone.

Keywords: carbon nanotubes; charge transfer; cyclohexane oxidation; in situ spectroscopy; reaction mechanisms.