H₂ Storage Projects

Transition Metal-Decorated Nanotubes and C ₆₀; high-capacity hydrogen storage medium

Introduction | Dissociative Absorption of H2 | Molecular Absorption | 4th top-H2 | The lowest energy isomer | Bonding Mechanism | Does Pt/Pd also work? | MD simulations | High concentration metal-coverages | Ti-decorated C60 | Conclusions

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CONCLUSIONS

• In conclusion, using accurate first-principles total-energy calculations we have shown that each Ti atom adsorbed on a small diameter nanotube or C60 can bind up to four hydrogen molecules, a remarkable and totally unanticipated finding.

• The strong interaction is due a unique combination of chemical and ionic bonding between titanium d, carbon p and hydrogen s-electrons.

• These results advance our fundamental understanding of dissociative and molecular chemisorptions of hydrogen in nanostructures and suggest a possible method of engineering new nanostructures for high-capacity storage and catalyst materials.

• We hope that these results will motivate experimentalists to synthesize small radius nanotubes/C60 and find ways to coat them by Ti.

• It is also know that Ti forms several high-symmetry clusters with carbon such as metallocarbohedrene Ti8C12. It would be interesting to study the hydrogen adsorption properties of such Ti-C nanostructures.

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