Scandium/Lithium-Functionalized c-IRMOF-10 as a Highly Efficient and Fast-Kinetic Hydrogen-Storage Medium: An Ab Initio DFT and AIMD Study

Abstract

Isoreticular metal–organic framework-10 (IRMOF-10) beryllium-based nanoporous materials are receiving great interest as H2-storage media due to the low atomic mass of beryllium and the stability of decorating light metals (Li, Sc) on the organic linker by the hybridization of orbitals. In this computational theory, we first demonstrated the energetic stability of connector-IRMOF-10 (c-IRMOF-10) through density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations. Our results revealed that the Li and Sc atoms prefer to adsorb at the organic linker with binding energies of −306.82 and −411.02 kJ/mol, respectively. In the hydrogenation process, 8Li@c-IRMOF-10 and 8Sc@c-IRMOF-10 adsorbed 24 H2 and 28 H2 molecules, respectively, having average adsorption energies within the desired range for effective storage/release cycles. The maximum gravimetric density is found to be 8.27 and 6.78 wt % for Li- and Sc-decorated c-IRMOF-10, respectively. It is observed during the van‘t Hoff desorption and AIMD calculation study that Li/Sc@c-IRMOF-10 reversibly stores hydrogen under ambient conditions. H2 migration on the surface of Li/Sc@c-IRMOF-10 is confirmed to be fast along the ring center, owing to a low activation energy of ∼1.59/2.18 kJ/mol. We believe that our findings on functionalization/substitution methods are important for achieving the optimal H2-storage properties of c-IRMOF-10.

Reversible Hydrogen Storage in a Superalkali NLi4-Decorated Biphenylene Monolayer: Insights from a First-Principles Study

“…Two-dimensional (2D) materials have gained attention in storage applications owing to their exceptionally unique characteristics, such as their high surface area, lightweight nature, and multiple active sites, which make them highly promising for hydrogen storage. − In the pristine state, most 2D materials exhibit hydrogen binding through weak physisorption, leading to reduced capacities for hydrogen storage and restricting their functionality to low temperatures, rendering them unsuitable for practical applications. , Consequently, to enable effective storage and release under achievable storage conditions, there is a need to enhance the binding between 2D material and hydrogen, i.e., the H 2 adsorption energies onto the host material. , One approach to enhance the binding involves the functionalization of materials with metal, including alkali or alkaline metals as well as transition metals. − Influenced by this notion, multiple other studies have demonstrated increased H 2 storage as a result of such modifications. For instance, Nair et al conducted experimental investigations into effective hydrogen storage using Pd-decorated g-C 3 N 4 , revealing a gravimetric density of 2.6 wt % .…”

Lithium Functionalization in a Three-Dimensional Graphene Monolith for Enhanced Adsorption–Desorption Hydrogen Storage

“…These existing methods have drawbacks, including the need for cumbersome and costly containers, insufficient energy retention, the potential for liquid boil-off, and a significant risk of explosion, posing serious threats to human life. More specifically, hydrogen storage in solid-state materials is categorized into two forms: in the form of H 2 molecules, which weakly attach to the surface (physisorption), − and in the form of hydrogen atoms, which strongly bond with the surface (chemisorption). − The U.S. Department of Energy (U.S.DoE) has set a goal of achieving a theoretical H 2 -storage capacity of 5.5 wt % for mobile or stationary applications powered by H 2 . Furthermore, the ideal adsorption energy should fall within the range of {−0.15; −0.60 eV per molecule}, which is well-suited for hydrogen storage and release cycles under nearly standard conditions (233 to 358 K, 2–100 atm)…”