【摘要】 以改性无烟煤为助磨剂,在氢气气氛下球磨制备了具有纳米结构的镁铝合金储氢材料,通过SEM,XRD,TPD等手段对比研究了球磨吸氢材料及静态再吸氢材料的晶相结构及放氢动力学性能。结果表明:改性无烟煤具有良好的助磨作用,经5.5h球磨,材料平均粒度可达74nm;镁铝合金经反应球磨后,其中的Mg转化成了β-MgH2和γ-MgH2,放氢峰温低于300℃;静态再吸氢后,MgH2全部以β-MgH2存在,且晶体粒度增长60%,Mg17Al12分解为单质Mg和Al,其中单质Al使储氢材料放氢活化能降低,用Kissinger方程计算出球磨储氢和再吸氢材料的放氢一级表观活化能分别为107.3kJ/mol和67.1kJ/mol。更多还原

【Abstract】 Nanostructured Mg-Al alloy hydrogen storage material was prepared with modified anthracite as milling aid by ball milling under hydrogen atmosphere.The crystal phase structure and dehydrogenation kinetics properties of the ball milled hydrogen absorbing materials and static re-hydrogenated materials were analyzed by SEM,XRD and TPD.The results show that the modified anthracite plays a good milling aid role,after 5.5hof milling,the average particle size of Mg-Al alloy reaches to74nm;The Mg in the Mg-Al alloy transforms intoβ-MgH2andγ-MgH2 after reaction ball milling,whose peak dehydrogenation temperature is lower than 300℃.Yet,after static re-hydrogenation,the MgH2 all exists inβ-MgH2 which shows a 60%increase in crystal size,and the Mg17Al12 decomposes into elementary Mg and Al.The elementary Al decreases the dehydrogenation activation energy of hydrogen storage materials,where the hydrogen level of apparent activation energy of the ball milled hydrogen storage material and re-hydrogenated material is 107.3kJ/mol and 67.1kJ/mol,respectively,calculated according to the Kissinger equation.更多还原