This work reports the dihydrogen adsorption and storage capacity of cage-like clusters (C-12-Ti-6 and C-12-Ti-6(2+)) using density functional theory calculations. The neutral system C-12-Ti-6 can adsorb 15 hydrogen molecules, however, some hydrogen molecules will dissociate and bond atomically on titanium atoms. The strong binding energy will cause high operating temperature to desorb hydrogen during the application process. Fortunately, the cationic system C-12-Ti-6(2+) can adsorb up to 16H(2) all in molecular form. Moreover, the predicted maximal hydrogen storage density is 6.96 wt% and the average adsorption energies of C-12-Ti-6(2+) (nH(2)) (n = 1-16) are in the desirable range of reversible hydrogen storage at the 6-311G(d,p)-B3LYP and M06-2X levels. The interaction of C-12-Ti-6(2+) with hydrogen molecules is considered by means of the bond critical points (bcp) in the quantum theory of atoms in molecules (QTAIM). With respect to Gibbs free energy corrected H-2 adsorption energy, C-12-Ti-6(2+) adsorbs 16H(2) molecules should be at low temperature (190 K). These predictions show that cationic C-12-Ti-6(2+) is more suitable as a material for adsorbing dihydrogen. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.