| Hydrogen storage material with excellent performance is the key technology in the development of hydrogen energy. Carbon material with special crystallite was prepared from anthracite by deashing and carbonization. Then hydrogen storage material with high performance was prepared from the carbon and metal additive by high-energy reaction milling in hydrogen atmosphere.According to the principle and method of graphite production, the anthracite was pretreated by deashing and carbonization. The effect of the parameters of alkali sintering and acid abstersion on the deashing result was researched, and preferable deashing conditions were determined. The changing of carbon structure in the process of carbonization was analyzed. In preferable deashing conditions, the ash yield of the anthracite was reduced to 0.05%, and the deashing rate reached 99.3%. Results of FTIR (Fourier transform infrared spectrometer), XRD (powder X-ray diffraction) and iodine adsorption showed that heteroatoms in anthracite such as nitrogen, sulfur and oxygen decreased, crystallite structure of graphite-like formed, and theadsorption and milling properties increased after carbonization.By the method of reaction milling, hydrogen storage material was prepared from carbonand metal additive by high-energy milling in hydrogen atmosphere when the material hydrogenized rapidly. Adopting the method of drainage, the volume of hydrogen released during heating was measured by water exchanging method which is expedient, rapid and accurate, and then the hydrogen capacity was calculated. Technical parameters, such as the ratio of carbon to metal, hydrogen pressure, milling time and milling frequency, influenced the hydrogen storage capacity. Experimental results showed that the hydrogen capacity of material C40Mg50Al10, which was prepared in the conditions of carbon content 40%, hydrogen pressure 2MPa, milling time 2h, and milling frequency 45Hz, reached 5.82%, and by calculation the hydrogen capacity of the carbon should be over 5.05%.The microstructure and performance of hydrogen storage material C40Mg50Al10 were determined by TEM (transmission electron microscope), SAED (selected area electron diffraction), XRD and DSC (differential scanning calorimeter). The results showed that the particle size of the material was 20～40nm, and the granularity and dispersion were good. The inchoative dehydrogenation temperature was 227.4℃which was 60℃lower than that of magnesium, and the maximum dehydrogenation temperature was 303.4℃. So the dehydrogenation performance is much more favorable than that of magnesium.At last, on the basis of the results of structure characterization and performance test of the hydrogen storage material, the hydrogen storage mechanism was studied primarily. The theory of carbon crystallite formation, nanometerization and chemical hydrogen storage of carbon material was improved. Consequently, the foundation on how to increase the capacity of carbon material and improve its hydrogen storage performance was provided. |
