Chemical engineering of adamantane by lithium functionalization: A first-principles density functional theory study

Abstract

Using first-principles density functional theory, we investigated the hydrogen storage capacity of Lifunctionalized adamantane. We showed that if one of the acidic hydrogen atoms of adamantane is replaced by Li/Li + , the resulting complex is activated and ready to adsorb hydrogen molecules at a high gravimetric weight percent of around ∼7.0%. Due to polarization of hydrogen molecules under the induced electric field generated by positively charged Li/Li + , they are adsorbed on ADM.Li/Li + complexes with an average binding energy of ∼−0.15 eV/H 2 , desirable for hydrogen storage applications. We also examined the possibility of the replacement of a larger number of acidic hydrogen atoms of adamantane by Li/Li + and the possibility of aggregations of formed complexes in experiments. The stability of the proposed structures was investigated by calculating vibrational spectra and doing MD simulations.

Organometallic‐complex‐grafted adamantane as novel hydrogen‐storage material: A first principles computation

“…Many other works have reported that by replacing the hydrogen atom linking the top carbon atom with other atoms or functional groups, some new structures can be derived from adamantane 47, 48, 56, 57. Hence, we directly graft the C 5 H 5 Ti and C 6 H 6 Ti molecules on the top carbon atoms, and so up to four C 5 H 5 Ti or C 6 H 6 Ti molecules can be grafted onto one adamantane molecule at the maximum.…”

“…Diamondoids are hydrocarbons with cubic‐diamond structures that can be used as potential chemical building blocks for new materials 38. Because adamantane has a highly symmetrical and rigid structure and can be isolated in larger amounts from the crude oil, researches on it are rapidly emerging 39–48. Both experimental and theoretical studies show that adamantane molecules undergo self‐assemble on metal surfaces or into molecular crystals in vacuum with high porosity 39–46.…”

“…Both experimental and theoretical studies show that adamantane molecules undergo self‐assemble on metal surfaces or into molecular crystals in vacuum with high porosity 39–46. Due to the high stability of the adamantane, the hydrogen molecule binding energy on such compound is so small that it is not suitable for reversible H 2 adsorption/desorption near room temperature for hydrogen‐storage application 48. In this paper, we consider grafting the organometallic complexes C 5 H 5 Ti and C 6 H 6 Ti as functional groups onto the adamantane to design one new type of hydrogen‐storage materials.…”

Transition metal complexes with cage-opened diamondoid tetracyclo[7.3.1.14,12.02,7]tetradeca-6.11-diene

“…The electronic properties of such materials are determined by the diamondoid/metal interfaces that are firmly contacted resulting in welldefined conductance [19]. Generally, construction of stable hybrid materials based on diamondoid/metal combinations [20] are challenging as metallated diamondoids are reactive towards air and water [21,22]. (4), diamondoid dienes 5 and 6, and stable complexes 7 (M = Ag + , Pt 2+ ).…”

Crumpled Graphene-Storage Media for Hydrogen and Metal Nanoclusters

“…The idea of such a structure appeared when it was shown that the hydrogenation of graphene can lead to the buckling of the graphene sheet [54]: the amount of accumulated hydrogen increased from only 3 wt% for the simple graphene plane to 20 wt% for graphene plane with graphene cone. Carbon nanostructures doped with alkali metals (Li and K) can adsorb even more hydrogen [48][49][50][51][52][53]: 14 wt% (Li) and 20 wt% (K) of hydrogen at moderate conditions, in contradiction with the lower values reported later [50]. The Li-doped activated carbon [55] can store from 2.1 to 2.6 wt% of H 2 at 77 K and at 2 MPa, which shows that at given pressure-temperature conditions the amount of stored hydrogen can be increased.…”