A DFT Study on Ben (n=10-12) Clusters with Exceptional Room-Temperature Hydrogen Storage Capacity

In this studyt, we employed density functional theory (DFT) to conduct a comprehensive investigation into several critical aspects of Be _n (n = 10–12) clusters, including their structural configurations, hydrogen storage capabilities upon hydrogen adsorption, electronic properties, and thermal stability. Our findings reveal that Be _n (n = 10–12) hollow spherical clusters exhibit exceptional hydrogen storage capabilities. Even after adsorbing H₂ at room temperature, these clusters maintain excellent thermodynamic stability, as indicated by their electronic properties. Specifically, the Be₁₀ hollow spherical cluster can adsorb 26 H₂ molecules, achieving a hydrogen storage density of 31.96 wt%. The Be₁₁ cluster can adsorb 28 H₂ molecules with a storage density of 31.87 wt%, and the Be₁₂ cluster can adsorb 30 H₂ molecules, reaching a remarkable storage density of 35.87 wt%. These values far exceed the U.S. Department of Energy's target of 5.5 wt%. Through computational analysis, the average adsorption energy is determined to range between 0.16 eV and 0.19 eV/H ₂ , positioning it intermediately between physical adsorption and chemical adsorption. The IGMH isosurface analysis further corroborates that the H ₂ molecules exhibit characteristics indicative of physical adsorption. PDOS (Projected Density of States) analysis elucidates that the hydrogen storage mechanism is predominantly governed by the polarization of H ₂ molecules and van der Waals forces arising from the orbital hybridization between hydrogen atoms and the substrate material. The calculated desorption temperature indicates that at temperatures exceeding 216 K, this substrate material emerges as a potential candidate for reversible hydrogen storage. These three systems are identified as ideal for reversible hydrogen storage and release processes. The hollow spherical Be _n (n = 10–12) clusters are demonstrated to be a highly promising material for ultra-high-capacity hydrogen storage.