Hydrogenation reactions of three polycyclic arenes (PCAs), that is, anthracene, 9-phenylanthracene (PA), and 9,10-diphenylanthracene (DPA) were carried out under an initial hydrogen pressure of 5 MPa at 300 degrees C. An activated carbon (AC, a metal-free catalyst), was employed to catalyze the PCA hydroconversions. The results show that the AC can split gaseous hydrogen into atomic form and catalyze monatomic hydrogen transfer to aromatic rings. Interestingly, the AC selectively catalyzed the hydrogenation of the anthracene ring, and prevented the benzene ring from hydrogenation and the C-C linkage from cleavage. The reactivity of the PCAs toward hydrogenation over the AC decreased in the order of anthracene > PA > DPA. The hydrogen-accepting ability and steric hindrance effect are demonstrated to be responsible for the difference in reactivity.