Study On Hydrogen Storage Performance Of A Class Of Clusters

In recent years,environmental problems associated with the use of fossil fuels have become increasingly serious.Because hydrogen can be easily prepared from water,and because the Earth's water resources are abundant,and because hydrogen is clean when it is burned to produce water,and because it can be re-prepared from the water it burns to be recycled,hydrogen is becoming a promising alternative to fossil energy and the most important new energy fuel of the future.But how to safely and efficiently store and transport hydrogen is currently the biggest obstacle to putting it into large-scale use as a new energy fuel.Research to find suitable hydrogen storage materials has become imperative.Such two-dimensional hydrogen storage materials like graphene,whose original mass is lighter and larger than the surface area,have great advantages in hydrogen storage.However,graphene alone cannot be used as a hydrogen storage material because its adsorption to hydrogen molecules is physical and its adsorption energy is too low for large amounts of hydrogen storage.It has been found that graphene modified with Na,Ca,Sc and other metal atoms greatly improves the adsorption energy of hydrogen.However,the metal atoms used to modify graphene can easily form clusters on its surface,and the metal atoms that form clusters can not only not be used to store hydrogen,but also reduce the hydrogen storage mass ratio to some extent.The hydrogen storage potential of C₆₀has been exploited following the complete theoretical and experimental confirmation of C₆₀'s inorganic non-metallic caged clusters.Based on this,this paper attempts to find new carbon-based clusters and finds the carbon-based cluster C₂₀.In this paper,the hydrogen storage process of C₂₀is investigated using the first nature principle density flood function theory and the main work is as follows.First,the modification of fullerene C₂₀by three metal atoms,namely alkali metal atoms,transition metal atoms and light metal atoms,was carried out,but due to the instability of the obtained optimized structure,the fullerene C₂₀modified by metal atoms was structurally dispersed during the adsorption of H₂molecules and thus could not effectively adsorb H2 molecules.Secondly,in this paper,the fullerene C₂₀with carbon atomic chains connected at the Ti end and the fullerene C₂₀with boron and nitrogen atomic chains connected at the Ti end were investigated and doped with Ti atoms at the tails of the carbon and boron nitrogen chains at the four tips of the C₂₀and found to have a strong hydrogen storage capacity.The results show that the fullerene C₂₀with the boron and nitrogen chains on the Ti end has a hydrogen mass density of 14.4 wt%and can bind up to 56 H₂molecules with an average binding energy of 0.34eV/H₂,while the fullerene C₂₀with the carbon chains on the Ti end also has a good hydrogen adsorption capacity of 10.7 wt% and can bind up to 40 H₂molecules with an average binding energy of 0.30eV/H₂.Finally,this paper attempts to connect two C₂₀s by benzene rings and modify the structure by metal Na and metal Sc atoms.It is found that the benzene ring-linked fullerenes C₂₀can adsorb 60 H₂molecules with a corresponding hydrogen mass density of 10.03 wt%and an average binding energy of 0.22eV/H₂,which also has a good hydrogen storage function.The results of this paper provide another new idea and method for hydrogen storage for small clusters that cannot be effectively modified by metal atoms.