TM₈B₆(TM=Ni、Pd)作为可逆储氢材料的计算研究

Two density functional theory methods were employed to evaluate the H₂ storage capabilities of metallo-borospherenes TM₈B₆ (TM=Ni, Pd). Consequently, the superatoms Ni₈B₆ and Pd₈B₆, which accommodate 40 and 32 H₂ molecules, respectively, exhibit gravimetric H₂ uptake capacities of 13.134% and 6.562%, respectively. The average binding energies of Ni₈B₆(H₂)₄₀ and Pd₈B₆(H₂)₃₂ fall within the optimal range for reversible H₂ storage applica-tions. The interactions between H₂ molecules and the parent structures were characterized using various wave func-tion analysis methods. Polarization effects, alongside the Kubas mechanism, are pivotal to the adsorption of H₂ on TM₈B₆. Moreover, the investigations examine the effect of temperature on the H₂ storage capacity of TM₈B₆ at atmospheric pressure. Atom-centered density-matrix propagation molecular dynamics simulations confirm the reversibility of H₂ adsorption and desorption cycles. The thermodynamic analyses of the desorption behavior of H₂ molecules were conducted via a three-dimensional graph, plotted based on the relationship between the number of adsorbed H₂ molecules and temperature as well as pressure, revealing that the majority of adsorbed H₂ molecules can be released at 0.5 MPa and 358 K. Compared to the respective monomeric counterparts, the H₂ storage densities of (TM₈B₆)₂ dimers exhibit a slight reduction.