The Preparation And Properties Study Of Catalysts Doped LiBH₄as Hydrogen Storage Materials

Based on full review on the advantages and disadvantages of all kinds ofhydrogen storage materials, this thesis focuses on the the study of LiBH4ashydrogen storage material. Additives doped LiBH4systems were prepared by ballmilling processing. A variety of characterization methods, such as thermogravimetry（TG）, differential scanning calorimetry （DSC）, X-ray diffraction （XRD）, Fouriertransform infrared spectroscopy （FTIR） and pressure-composition-temperatureinstrument （PCT）, were used for studying of hydrogen storage/releaseperformance,catalytic performance, kinetics and thermodynamics of materials.This thesis focuses on investigating of the influence law of single doped andco-doped Fe₂O₃and TiF3in the2LiBH₄-MgH₂system on hydrogen storageperformance. All the results showed that either the Fe₂O₃or TiF3single doping canimprove the dehydriding and re-hydriding properties of the system, and the co-dopedsystems are more favourable than the single ones. The TG results showed that whenthe doping content was5.0wt.%, the co-doped system began to release hydrogen at120℃and the total hydrogen desorption capacity was8.8wt.%. The PCT resultsshowed that the co-doped system completed the hydrogen evolution processingwithin10min at400℃. The results also showed that the kinetics andthermodynamics of co-doped systems were better. Further increasing the additionamount could better improve the storage/release of hydrogen performance. When thedoping content was10wt.%, the co-doped system began to release hydrogen at110℃and the total hydrogen desorption capacity was9.6wt.%.The mesoporous Fe₂O₃was prepared in laboratory and the influence law ofmesoporous Fe₂O₃doped in the LiBH4system was investigated, using thecommercial Fe₂O₃（defined as Fe₂O₃’） as reference sample. The LiBH4-30wt.%mesoporous Fe₂O₃and LiBH4-30wt.%Fe₂O₃’ system were prepared by ball millingprocessing. The TG results showed that the mesoporous Fe₂O₃doped in the LiBH4began to release hydrogen at75℃, compared with the205℃of the Fe₂O₃’ doped system. The mesoporous Fe₂O₃exhibited a better catalytic effect.This thesis also focuses on the influence law of mesoporous Fe₂O₃and TiF₃co-doped in the LiBH₄system prepared by ball milling processing. A series ofdifferent systems were studied via changing the additive content. The TG resultsshowed that when the TiF₃doping content was30wt.%, the co-doped system beganto release hydrogen at60℃and the total hydrogen desorption capacity was5.7wt.%at215℃. The DSC and PCT results also showed that the co-doped systemexhibited better kinetics and thermodynamics than that of pure LiBH₄.