# A DFT Study on Ben(n = 10–12) Clusters with Hydrogen Storage Capacity

## TL;DR

This study uses DFT to show that beryllium clusters can store large amounts of hydrogen efficiently and stably at room temperature.

## Contribution

The study identifies beryllium clusters as promising materials for ultra-high-capacity reversible hydrogen storage.

## Key findings

- Be10, Be11, and Be12 clusters can store 26, 28, and 30 H2 molecules, respectively, with storage densities exceeding 31.87 wt%.
- Adsorption energy of H2 is between 0.16 and 0.19 eV/H2, indicating a balance between physisorption and chemisorption.
- Desorption above 216 K suggests potential for reversible hydrogen storage in these clusters.

## Abstract

Hydrogen energy has garnered widespread attention as a clean energy source. This study employs density functional theory (DFT) to systematically investigate the hydrogen storage performance of Ben(n = 10–12) clusters. The results reveal that hollow spherical Ben clusters exhibit excellent hydrogen storage capacity while maintaining good thermal stability even after H2 adsorption at room temperature. Specifically, Be10, Be11 and Be12 clusters can adsorb 26, 28, and 30 H2 molecules, achieving hydrogen storage densities of 31.96 wt%, 31.87 wt%, and 35.87 wt%, respectively—far exceeding the U.S. Department of Energy’s target of 5.5 wt%. Calculations indicate an average adsorption energy between 0.16 and 0.19 eV/H2, which lies between physisorption and chemisorption. IGMH isosurface analysis confirms the physisorption characteristics of H2 molecules. PDOS analysis reveals that the hydrogen storage mechanism primarily originates from H2 molecular polarization and van der Waals forces arising from orbital hybridization between hydrogen atoms and the substrate. Desorption temperature calculations show that, above 216 K, this material demonstrates potential for reversible hydrogen storage. This study demonstrates that these three hollow spherical beryllium cluster systems are ideal candidates for achieving ultra-high-capacity reversible hydrogen storage.