Density Functional Theory Study of Li-Functionalized Nanoporous R-Graphyne–Metal–Organic Frameworks for Reversible Hydrogen Storage

Abstract

Hydrogen is the most convenient recourse to shift from fossil fuels to an efficient and sustainable source of energy in automobiles. Achieving a high hydrogen weight percentage while storing hydrogen is the prime challenge in using hydrogen fuel. In the current study, a nanoporous metal−organic framework of 2.069 nm pore size having R-graphyne as a linker (G R −MOF) is reported for the first time. Employing density functional theory, the hydrogen sorption characteristics of G R −MOF functionalized with Li and its mechanism are investigated. A Kubas-like mechanism is observed in the process of hydrogen adsorption with sorption energies in the 0.25−0.27 eV range, with the highest hydrogen weight percentage of 11.95%. It is observed during the van 't Hoff desorption and Born−Oppenheimer molecular dynamics study that G R −MOF reversibly stores hydrogen under operable thermodynamic conditions (100−300 K, 1−3 atm). G R −MOF stands out to be a prospective material for reversible hydrogen storage under the norms set by the Department of Energy, USA.

First-Principles Study of Hydrogen Storage of Sc-Modified Semiconductor Covalent Organic Framework-1

“…The parameters are set to a constant number of atoms, a constant volume, and constant temperatures of 300 and 400 K. We set the MD simulation time to 1.5 ps to have enough time to complete the calculation, which is consistent with the published reports. 56 , 63 , 68 − 70 Figure 9 a,b shows the molecular dynamics simulation results of the adsorption of 24 H 2 molecules by 6Sc-COF-1 at 300 and 400 K, respectively. It can be seen that the COF-1 structure does not undergo significant deformation and the six Sc atoms are still stably adsorbed on the COF-1 layer without aggregation at both 300 and 400 K. One of the four hydrogen molecules adsorbed by each Sc atom escapes at 300 K, and all of the adsorbed H 2 molecules are released when the temperature is 400 K. It is demonstrated that the adsorption and desorption of hydrogen molecules can be achieved within a narrow temperature range of 300–400 K and 6Sc-COF-1 has excellent reversibility as a hydrogen storage material.…”

Hybrid Two-Dimensional Porous Materials

“…While experimental reports on graphyne−MOF hybrids are currently lacking, a recent study using DFT has shown that a Li-functionalized graphyne−MOF hybrid has the potential for hydrogen storage. 96 MXenes stand out among 2D materials for their ability to form diverse structures with rich surface chemistry. In this direction, Wang and co-workers reported MXene-based Ti 3 C 2 Tx@ZIF-8 dual-layered membrane by using electric field-assisted methods as electrophoretic deposition (EPD) and fast current-driven synthesis (FCDS) (Figure 6a).…”

Tunable Electrochemical Hydrogen Uptake and Release of Nitrogen-Doped Reduced Graphene Oxide Nanosheets Decorated with Pd Nanoparticles

“…9−11 In recent years, significant research has been focused on developing various physical and chemical forms of hydrogen storage, including functionalized graphene, 7,12−14 activated carbons, 15,16 carbon nanotubes, 17−19 drides, 20−23 and metal-organic framework materials. 24,25 While these materials are able to stably store hydrogen during transportation and can be easily released under working conditions, multiple challenges still exist.…”

“…In response to the rising energy demand, depletion of limited fossil fuels, and continuous rise in environmental pollution, it is crucial to develop energy storage materials that are easily accessible and have high energy density. − Hydrogen is identified as a promising alternative energy carrier due to its high gravimetric energy density, the potential for producing zero emissions, and abundance. , Despite these benefits, the practical use of hydrogen is limited by the difficulty of safe, cost-effective storage and transportation. − While traditional hydrogen storage methods such as pressurized and liquid hydrogen have been well established, the use of expensive carbon fiber-reinforced tanks and boil-off concerns remain problematic. − In recent years, significant research has been focused on developing various physical and chemical forms of hydrogen storage, including functionalized graphene, ,− activated carbons, , carbon nanotubes, − metal hydrides, − and metal-organic framework materials. , While these materials are able to stably store hydrogen during transportation and can be easily released under working conditions, multiple challenges still exist.…”