Toward Efficient Hydrogen Storage: A Quantum Chemical Study of Beryllium Clusters

Area of Science:

• Materials Science
• Computational Chemistry
• Nanotechnology

Background:

• Lightweight materials for reversible hydrogen storage are crucial for hydrogen energy technologies.
• Developing materials that store hydrogen under practical conditions presents a significant challenge.
• Beryllium clusters are explored as potential candidates for hydrogen storage applications.

Purpose of the Study:

• To systematically investigate the structural stability and hydrogen adsorption properties of beryllium clusters (Be_n, n=3-25).
• To evaluate the suitability of beryllium clusters for reversible hydrogen storage.
• To understand the size-dependent behavior of hydrogen adsorption in beryllium clusters.

Main Methods:

• Density Functional Theory (DFT) calculations were employed for structural and adsorption property analysis.
• Benchmark calculations using DLPNO-CCSD-(T) validated the accuracy of the ωB97X-3c functional.
• Electronic structure analyses (energy decomposition, density of states, IGMH) elucidated adsorption mechanisms.

Main Results:

• Beryllium clusters exhibit predominantly molecular physisorption with optimal adsorption energies for reversible storage.
• The Be14 cluster demonstrated exceptional performance, storing up to 20 H2 molecules with high gravimetric density (24.2 wt%) and reversible capacity (17.86 wt%).
• Favorable desorption temperatures (127-259 K) and ultrafast kinetics were predicted for Be14.

Conclusions:

• The Be14 cluster is identified as a highly promising nanoscale material for reversible hydrogen storage.
• Hydrogen uptake in these clusters is governed by cooperative, noncovalent interactions.
• This study provides fundamental insights into size-dependent hydrogen adsorption in light-element clusters.