Effects Of Modified Ferrierite And Porous Oxide On Hydrogen Storage Properties Of LiBH₄

Hydrogen is a new energy which has gradually attracted widespread attention, while its key barrier that prevents hydrogen energy from practical application is the technique of hydrogen storage. LiBH4 has been attracting a great deal of attention due to its high hydrogen capacities. Unfortunately, but its commercialization is hampered by sluggish kinetics. In this paper based on an overview on the research of LiBH4 for hydrogen storage,the method of melt impregnation is selected to optimize the LiBH4 system. Then the phase structure and mechanisms are also investigated systematically.In this paper the FER(ferrierite) has unique two-dimensional pore system consisting of 10-ring channels intersected by 8-ring channels which was synthesized by hydrothermal synthesis method. The protonated ferrierite was prepared which was called HFER. It was obtained by NH4+ exchange then changing the sodium type FER into H-type HFER. In this way the density and intensity distribution of acid sites on the surface was adjusted, then it could improve the catalytic activity. This paper also studied the metal loaded HFER which contained Ni loaded HFER(defined as Ni/HFER) and Pt loaded HFER(defined as Pt/HFER), then LiBH4 was confined into different framework materials by using the method of melt impregnation. P-C-T test showed that at 400 oC, LiBH4- HFER composite could release 3.3 wt.% hydrogen in 3000 s, then uptaking 5.9 wt.% hydrogen in 2000 s.XRD test showed that it may be due to the process of Li3BO3 and Li2B4O7 generated in the process which played as catalytic roles. In addition, compared with HFER, the metal loaded HFER behaved better catalytic effect, which may be due to the high dispersion of metal showed in the SEM test and TEM test. This characteristic could expand the specific surface area of the composite material and increase the active site, then playing a good catalytic effect.Porous oxides were also studied in this paper containing porous Al2O3(defined as Al2O3,) and porous Zr O2(defined as Zr O2,) which was synthesized by template method,then exploring the mechanisms with LiBH4. SEM and TEM tests showed that the grain size of porous oxides are very small and the special structure increased the specific surfacearea, which can significantly improve the hydrogen performance of LiBH4. TPD test showed that when LiBH4 confined with porous oxides, the initial hydrogen desorption temperature decreased by 107 oC and 83 o C, respectively. Compared with LiBH4, the hydrogen desorption activition energy of the materials also decreased by 82.59 kJ·mol-1and 100.42 kJ·mol-1, respectively, reducing the energy barrier and improving the thermodynamic property.