Fellah Mehmet Ferdi
Department of Chemical Engineering, Bursa Technical University, 16310, Bursa, Turkey.
J Mol Model. 2017 Jun;23(6):184. doi: 10.1007/s00894-017-3349-1. Epub 2017 May 9.
Hydrogen molecule adsorption on frameworks consisting of alkaline earth metal atoms (Be, Mg, or Ca) in LTL zeolite was investigated via density functional theory. A 24T zeolite cluster model was used in this study. HOMO and LUMO energy, chemical potential, chemical hardness, electronegativity, adsorption energy, and adsorption enthalpy values were calculated. The Mg-LTL and Ca-LTL clusters were found to have much lower chemical potentials and adsorption energies than those of the Be-LTL cluster. Additionally, the calculations indicated that the Mg-LTL and Ca-LTL clusters are softer (considering their lower chemical hardness values) and more chemically reactive than the Be-LTL cluster. The calculated hydrogen adsorption enthalpies were -14.7 and -9.4 kJ/mol for the Mg-LTL and Ca-LTL clusters, respectively, which are significantly larger than the enthalpy of liquefaction for the hydrogen molecule. These results imply that the Mg-LTL and Ca-LTL zeolite structures are promising cryoadsorbents for hydrogen storage. Graphical abstract Hydrogen adsorption was theoretically investigated on Be-, Ca- and Mg-LTL clusters. Ca- and Mg-LTL zeolites are potential cryoadsorbent materials for hydrogen storage.
通过密度泛函理论研究了氢分子在由LTL沸石中的碱土金属原子（Be、Mg或Ca）组成的骨架上的吸附。本研究使用了一个24T沸石簇模型。计算了最高占据分子轨道（HOMO）和最低未占据分子轨道（LUMO）能量、化学势、化学硬度、电负性、吸附能和吸附焓值。发现Mg-LTL和Ca-LTL簇的化学势和吸附能比Be-LTL簇低得多。此外，计算表明，Mg-LTL和Ca-LTL簇比Be-LTL簇更软（考虑到它们较低的化学硬度值）且化学反应性更强。Mg-LTL和Ca-LTL簇的计算氢吸附焓分别为-14.7和-9.4 kJ/mol，这明显大于氢分子液化的焓。这些结果表明，Mg-LTL和Ca-LTL沸石结构是有前景的储氢低温吸附剂。图形摘要从理论上研究了氢在Be-LTL、Ca-LTL和Mg-LTL簇上的吸附。Ca-LTL和Mg-LTL沸石是潜在的储氢低温吸附剂材料。
