A highly active solid acid for specifically catalyzing di(1-naphthyl)methane hydrocracking in cyclohexane

A highly active solid acid was prepared by impregnating trifluoromethanesulfonic acid (TFMSA) onto mesostructured zirconium oxide (MSZO). Di(1-naphthyl)methane (DNM) was used as a coal-related model compound to evaluate the catalytic activity of TFMSA/MSZO for cleaving strong C-C bridged bonds in coals. As a result, TFMSA/MSZO was found to be effective for hydrocracking DNM to naphthalene and 1-methylnaphthalene in cyclohexane without adding gaseous hydrogen and MSZO is a much better support than activated carbon, γ-Al2O3, and ZSM-5 zeolite. Based on the kinetic investigation, the apparent activation energy of DNM hydrocracking over TFMSA/MSZO is only 32.0 kJ·mol−1, which is much lower than the dissociation energy (355.6 kJ·mol−1) of the bridged bond in DNM. The proton transfer directly from TFMSA/MSZO and/or via cyclohexane dehydrogenation over TFMSA/MSZO to the ipso-position of DNM could be the crucial step for DNM hydrocracking.