Hydrogen storage in magnesium decorated boron clusters (Mg2Bn, n = 4–14): A density functional theory study. (28th April 2020)

• Record Type: Journal Article
• Authors: Kumar, Aditya; Vyas, Nidhi; Ojha, Animesh K.
• Is Part Of: International journal of hydrogen energy. Volume 45:Number 23(2020)
• Page Start: 12961
• Page End: 12971
• Publication Date: 2020-04-28
• Subjects: DFT -- Adsorption -- Magnesium-based boron cluster -- Hydrogen storage; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2020.03.018
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The capacity of hydrogen adsorption of magnesium (Mg) decorated small boron (B) clusters (Mg2 Bn ; n = 4–14) was studied using density functional theory (DFT). The calculated results indicate that H2 adsorbed in the molecular form. The Bader's topological analysis indicates the presence of closed shell type interaction between clusters and H2 molecules. The clusters are stable even after the adsorption of H2 molecules. The average energy of H2 adsorption is calculated to be in the range of 0.13–0.22 eV/H2 . The Mg2 B6 cluster shows maximum H2 adsorption (8.10 wt%) at ambient temperature and pressure. Further, we have performed molecular dynamic (MD) simulation at room temperature for each cluster to understand adsorption and desorption of H2 molecules with time. The MD simulation revealed that most of the adsorbed H2 molecules moved away from the clusters within 200 fs. However, one H2 molecule remains attached with the Mg2 B11 cluster even after 200 fs. Highlights: The H2 storage capacity of Mg2 Bn (n = 4–14) clusters was investigated at ambient temperature and pressure using DFT. These clusters were found to be highly stable. The Mg2 B6 cluster showed H2 adsorption of 8.10 wt% with average adsorption energy 0.19 eV/H2 . The topological analysis revealed that the clusters were stable against adsorption and desorption. Molecular dynamics analysis shows that within few fs desorption of H2 was started.