Ab initio study of boron and aluminum hydrides nanoparticles

• Published in: International journal of hydrogen energy Vol. 41; no. 44; pp. 20210 - 20216
• Main Authors: Michos, F.I., Sgouros, A.P., Sigalas, M.M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 26-11-2016
• Subjects: Boron and aluminum hydrides; DFT calculations; Nanoparticles; Nanoparticles; Boron and aluminum hydrides; DFT calculations
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2016.09.011

Using Density Functional Theory (DFT), the desorption energies of Hydrogen in Aluminum, and Boron nanoparticles (NPs) is calculated. The type of NPs studied here, were MnHm with M = Al or B, n varying from 2 up to 20 and m/n between 0 and 3. NPs combining the two atoms (Aln−xBxH3n) were also examined. These types of clusters combine the low weight of B with the low desorption energies of Al. For each NP, several different geometries were studied in order to find the one with the lowest energy.
•Using DFT methods, the geometries and desorption energies of BnHm and AlnHm nanoparticles were calculated. For BnHm, the NPs break into small clusters, while this phenomenon becomes more intense as n increases.•For AlnHm clusters, the maximum number of hydrogen that can be absorbed is m = 3n.•For NPs with certain number of n, the desorption energy mostly decreases as m increases. For fully hydrogenated NPs (m = 3n), the desorption energy decreases as n increases and extrapolating to very high values of n, the ΔEd tends to 7.283 kJ/mol H2.•In mixed Aln−xBxH3n clusters ΔEd increases almost linearly as x (B content) increases reaching a value of about 48 kJ/mol H2 for Al10B10H60.•Aln−xBxH3n NPs display higher desorption energies than pure aluminum hydrides hence, making them more thermodynamically stable.