First Principles Investigation on H2 Adsorption on the Pristine 2-Dimensional Hexagonal Aluminum

International Conference on Sustainable Energy and Green Technology 2018

能源学;生态环境科学

Villagracia, A.R.^1^3 ; Ong, H.L.^2 ; David, M.^1^3 ; Arboleda, N.^1^3

Physics Department, De la Salle University, Manila

0922, Philippines^1

School of Materials Engineering, Universiti Malaysia Perlis, Perlis, Arau, Malaysia^2

Advanced Nanomaterials Investigation by Molecular Simulations, DLSU, Manila, Philippines^3

关键词: Density difference;    Density of state;    First-principles investigations;    Hexagonal lattice;    Hydrogen molecule;    Production of hydrogen;    Theoretical investigations;    Theoretical study;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/268/1/012135/pdf
DOI  :  10.1088/1755-1315/268/1/012135

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

Lightweight hydrogen storage with high storage capacity is one of the challenges in pursuing a hydrogen economy as a source of clean energy. Aluminum has been proposed as a material for storage and production of hydrogen. Recent theoretical studies have established the feasibility of 2D hexagonal lattice structure aluminum. In this study theoretical investigation on 2D h-aluminum was performed employing density functional theory to study the energetics of hydrogen molecule and 2D h-aluminum system. Hydrogen molecule on top, hollow and bridge sites of hexagonal lattice were geometrically optimized to determine if hydrogen molecule would dissociate or adsorbed as a molecule. Results showed that hydrogen molecule can be physisorped mainly in the bridge site (-0.463 eV) at a distance of 3.1 Å, while it can dissociate at the top site with an activation energy of 1.51 eV. Electron density difference shows transfer of 0.60e- from hydrogen atoms to the aluminum atoms. Density of states showed broadening of energy levels and their general shift towards lower energies, and alignment of the orbitals showing sp hybridization. Results of this study can be used in further investigation on doped or decorated systems of 2D h-aluminum.