碳载钯对镁基储氢合金吸放氢性的影响.docx

碳载钯对镁基储氢合金吸放氢性能的影响 内 容 摘 要 镁基储氢材料由于资源丰富、储氢量高(MgH2理论容量达7.6%)、价格低廉、对环境污染小，被认为是最有发展前景的储氢材料之一。但吸放氢温度高和吸放氢动力学性能差等缺点，限制了其实用化进程。为了提高镁基储氢材料的储氢性能，本文研究了多壁碳纳米管载钯Pd/MWNCTs的不同载钯量对镁基氢化物吸放氢性能的催化效应。首先利用液相化学还原法制备钯载量分别为10%、20%、30%、40%的多壁碳纳米管载钯，然后与Mg粉混合成Mg95-Pdm/MWNCTs5-m(m=0.5、1、1.5、2)，并采用氢化燃烧合成法(HCS)制备镁基氢化物，最后机械球磨(MM)10h。结果表明，多壁碳纳米管载钯可明显提高镁基储氢材料的储氢性能：(1) 大幅提高HCS法制备MgH2的氢化程度；(2) 样品Mg95-Pd2/MWNCTs3在473K下，180s内，饱和吸氢量达到6.66 wt.%；(3) 在473K下，放氢量达到0.20wt.%。随着温度的升高，样品放氢量与放氢速率迅??提高，如：573 K，1800s 放氢量达到6.12 wt.%。 关键词：镁基储氢材料 钯碳催化剂 机械球磨 氢化燃烧合成 Abstract To improve the hydrogen storage performance of magnesium, multi-wall carbon nanotubes supported palladium was added to HCS+MMed magnesium. Firstly, MWCNTs supported Pd (Pd/MWNCTs) with different amounts of Pd (10wt.%, 20wt.%, 30wt.%, 40wt.%) were prepared by a solution chemical reduction method. Then, Mg95-Pdm /MWCNTs5-m (m=0.5, 1, 1.5, 2) were prepared by hydriding combustion synthesis (HCS) and 10 h mechanical milling (MM). The results indicated that Pd/MWNCTs can improve  HYPERLINK /dict_result.aspx?searchword=%e6%98%8e%e6%98%be%e6%8f%90%e9%ab%98tjType=sentencestyle=t=improved+obviously obviously the hydrogen storage performance of Mg-based  HYPERLINK app:ds:hydride hydride. Firstly, Pd/MWNCTs can  HYPERLINK /dict_result.aspx?searchword=%e5%a4%a7%e5%b9%85%e5%ba%a6tjType=sentencestyle=t=greatly greatly increase hydrogenation degree of magnesium in the HCS process. Then, the Mg95-Pd2/MWNCTs3 required only 180s to reach its saturated hydrogen capacity of 6.66wt.% at 473K. Lastly, at 473K, the hydrogen desorption capacity of the Mg95-Pd2/MWNTs3 reached 0.20 wt.%. The capacity and rate of hydrogen desorption were both increased greatly with increasing temperature，e.g., at 573 K, the hydrogen desorption capacity of the Mg95-Pd2/MWNTs3 reached 6.12 wt.% within1800s。 Key words: Mg-based materials Pd/MWCNTs catalyst Mechanical milling Hydriding combustion synthesis 碳载钯对镁基储氢合金吸放氢性能的影响 Effect of carbon supported palladium on the