Hydroconversion of 4-(1-naphthylmethyl) bibenzyl (NMBB) in the absence and presence of sulfur (S) was carried out with transition metal catalysts such as metallic iron fine powder, iron oxides, iron sulfates, iron sulfide, stabilized metallic nickel, supported ruthenium, rhodium and palladium on carbon under hydrogen of 10MPa at 350℃. In the case of the absence of S, the activity of transition metal catalyst was affected with the form of precursor used, and the reaction was proceeded within hydrogenation of aromatic-rings of NMBB and the reaction products were constituted of many kinds of the corresponding hydrogenated compounds of NMBB. In the cases of the presence of S, the catalytic activities of iron compounds were increased on the hydrocracking of NMBB, without ferric sulfate. The remarkable results in the presence of S were the appearance of active sites of C_<ar>-C_<alk> bond scission between naphthalene-ring carbon C_<ar> and methylene carbon C_<alk> in NMBB molecule by using of noble metal catalysts such as Ru, Pd and Rh supported on carbon, and the hydrogenation activity of NMBB to the corresponding compounds was depressed. Ratio of the rate of C-C bond scission to the rate of hydrogenation was depended on the kind of metal.
