Enhancing Hydrogen Cluster Storage in Clathrate Hydrates via Defect-Mediated Lattice Engineering

Abstract

Can we create even more “plenty of room at the bottom” of the confined nanospaces in clathrate hydrates by tuning the complex interactions between the host water frameworks and guest molecules? Because the lattice of the clathrate hydrate is stabilized by van der Waals forces between the host and guest, irradiating the lattice of the clathrate hydrate with energetic particles is anticipated to introduce artificial defects on the host water molecules, resulting in creating a better occupation of guest molecules. Here, we explored the effects of proton irradiation on the intermolecular hydrogen and intramolecular polar covalent bonds in the host frameworks of THF hydrates. The distinct roles of the secondary guest molecules in the lattice elongation of the proton irradiated THF hydrates were examined experimentally. Conclusively, multiple occupations of H2 in small cages was observed at moderate pressure and temperature conditions following H2 reloading of the lattice elongated THF hydrate.

Two-photon chemistry of tetrahydrofuran in clathrate hydrates

“…75,83 However photoelectrons liberated from ice by two-photon excitation at 265 nm would not possess energies higher than ∼1.4 eV 69,70 rendering THF fragmentation unlikely since its weakest bond (C–O) has a dissociation energy is ∼3.6 eV. 84 As mentioned earlier, all comparable clathrate studies including those in THF hydrates, 23,35 employing γ-rays or protons with energies in excess of 1 MeV display distinct radical spectra from those we observe. We posit that these higher energy irradiation sources are more likely to induce electron chemistry than two-photon threshold ionization due to increased recombinational escape probability, 68,85 additional electron sources from Auger emission following core-level ionization, 86 and the possibility of electron-impact ionization.…”

Prospect and Challenges of Hydrate-Based Hydrogen Storage in the Low-Carbon Future

“…Since the later half of 2000s, there has been a growing interest in promoting H 2 hydrate formation. − Notable H 2 hydrate promoters are tetrahydrofuran (THF), − , propane (C 3 H 8 ), ethane (C 2 H 6 ), tetra- n -butyl ammonium bromide (TBAB), , tetra- n -butyl ammonium fluoride (TBAF), tetra- n -butyl ammonium chloride (TBACl), tetra- n -butyl phosphonium bromide (TBPB), dioxolane (DIOX), , tetrahydrothiophene (THT), , tetra- n -butyl ammonium hydroxide (TBAOH), methylcyclohexane (MCH), , 1,1-dimethylcyclohexane (DMCH), , methyl tert -butyl ether (MTBE), , furan, 2,5-dihydrofuran (DHF), tetrahydropyran (THP), cyclpentane (CP), epoxycyclopentane, noble gases such as argon, and a mixture of THF and dodecyl trimethylammonium chloride (DTACl) . The effects of these promoters on the hydrate formation rate and the H 2 storage capacity are shown visually in Figure a,b, respectively.…”

“…They found that the H 2 diffusion coefficient at 270 K and 20 MPa increased by a factor of 2 upon the presence of perchloric acid . Meanwhile, Moon et al showed that using proton irradiation to create defects on hydrate structures led to an enhanced kinetics of H 2 uptake …”

“…108,109 Recently, Nguyent et al indicated through in situ confocal Raman microspectroscopy that perchloric acid could act as a kinetics promoter for the insertion of H 2 molecules into the water network.89 89 Meanwhile, Moon et al showed that using proton irradiation to create defects on hydrate structures led to an enhanced kinetics of H 2 uptake 69. 5.2.…”

Advances in Nanomaterials for Sustainable Gas Separation and Storage: Focus on Clathrate Hydrates

“…Early on, clathrate hydrate drew attention as a potential replacement for conventional natural gas due to its natural gas hydrate form, which contains gas as a guest and exists in permafrost or sea floors . Recently, based on the unique physicochemical properties of clathrate hydrates, efforts have been made to utilize synthetic clathrate hydrates in various separation processes such as post- and pre-combustion CO 2 capture, H 2 storage, natural gas storage and transportation, wastewater desalination, and more. − ,− …”