Theoretical Study of Hydrogen Storage in Ca-Coated Fullerenes.

摘要: First principles calculations based on gradient corrected density functional theory and molecular dynamics simulations of Ca decorated fullerene yield some novel results: (1) C60 with 32 atoms each its 20 hexagonal 12 pentagonal faces is extremely stable. Unlike transition metal that tend to cluster a surface, remain isolated even at high temperatures. (2) C60Ca32 can absorb up 62 H2 molecules in two layers. The first 30 dissociate bind atomically the 60 triangular an average binding energy 0.45 eV/H, while remaining second layer quasi-molecularly 0.11 eV/H2. These energies are ideal for coated operate as hydrogen storage material near ambient temperatures fast kinetics. (3) gravimetric this reach 6.2 wt %. Simple model show limiting value higher fullerenes.