Titanium-functional group complexes for high-capacity hydrogen storage materials

Using first-principles density-functional electronic structure calculations, we propose functionalized organic molecules decorated with titanium atoms as high-capacity hydrogen storage materials. We study six kinds of functional groups which form complexes with Ti atoms and find that each complex is capable of binding up to six H-2 molecules. Among such complexes, Ti-decorated ethane-1,2-diol can store H-2'S with the maximum gravimetric density of 13 wt% and, under ambient conditions, a practically usable capacity of 5.5 wt%. We also present various forms of storage materials which are obtained by modifying well-known nanomaterials using Ti-functional group complexes. (C) 2008 Elsevier Ltd. All rights reserved.