Hydrogen storage reactions on Ti decorated carbon nanocones (CNC) are investigated by using the state
of the art density functional theory calculations. The single Ti atom prefers to bind at the bridge site
between two hexagonal rings, and can bind up to 6 hydrogen molecules with average adsorption energies
of 1.73, 0.74, 0.57, 0.45, 0.42, and 0.35 eV per hydrogen molecule. No evidence for metal
clustering in the ideal circumstances, and the hydrogen storage capacity is expected to be as large as
14.34 wt%. Two types of interactions are recognized. While the interaction of 2H2 with TieCNC is irreversible
at 532 K, the interaction of 3H2 with TieCNC is reversible at 392 K. Further characterizations of
the former two reactions are considered in terms of projected densities of states, simulated infrared and
proton magnetic resonance spectra, electrophilicity, and statistical thermodynamic stability. The free
energy of the highest hydrogen storage capacity reaction between 6H2 and TieCNC meets the ultimate
targets of department of energy at (233.15 K) and (11.843 atm) with surface coverage (0.941) and (direct/
inverse) rate constants ratio (1.35). |
