【作者】 王振华；

【导师】 周仕学；

【作者基本信息】 山东科技大学 ， 化学工艺， 2008， 硕士

【摘要】 本文以纳米镁碳复合储氢材料为研究起点,分别添加活性金属镍和二氧化钛粉末,来改善其吸放氢性能。材料经透射电镜（TEM）、选区电子衍射（SAED）,X射线衍射（XRD）、差式扫描量热分析仪（DSC）以及自行设计的排水法放氢装置等分析手段表征。文章着重研究了添加物对材料可磨性、粒度大小、储氢密度、吸放氢性能的影响,在此基础上探讨了纳米镁碳复合储氢材料的吸放氢机理。对镍粉不同添加量制备的纳米镁碳复合储氢材料60Mg30CxNi（x=0,1,4,7,10）进行分析表征得出:在镁粉、微晶碳粉中添加小粒径的镍粉进行氢化反应球磨,有利于制备出粒径较小、放氢温度较低的纳米镁碳复合储氢材料;且材料的放氢温度随着镍粉添加量的增加而降低,其中材料60Mg30C10Ni的初始放氢温度为223.9℃;材料的放氢量也受镍粉添加量的影响,在低温下随着镍粉添加量的增加,放氢量呈递增趋势;在高温下随着镍粉添加量的增加而减少。向镁粉、微晶碳粉中添加纳米二氧化钛粉末进行氢化反应球磨,当二氧化钛添加量超过20wt.%时,球磨过程中材料容易粘附于罐底,不利于制备出粒径较小的材料;当添加量在0～20%范围内时,随添加量的增加,材料储氢密度相应的增加;当添加量在20～50%时,随着添加量的增加,材料储氢密度降低;其中以材料50Mg30C20TiO₂的储氢密度最高可达3.94wt.%。对制备的材料进行机理分析得出,镍颗粒对于氢气的离解、吸附具有积极作用,从而提高了镁颗粒与氢气反应的速度及效率:二氧化钛在储氢材料中作用主要有催化离解氢气分子及物理吸附氢气分子。更多还原

【Abstract】 In this dissertation,the powder of nickel/titanium dioxide was added during reaction milling under hydrogen atmosphere,in order to improve nanometer Mg/C composite hydrogen storage materials’(NMCCM) hydriding/dehydriding performance.The NMCCM was tested by transmission electron microscope(TEM), selected area electron diffraction(SAED),powder X-ray diffraction(XRD), differential scanning calorimeter(DSC) as well as self-devised drainage.The effect of powder added on grindability,size,hydrogen storage capacity and hydriding/dehydriding properties are emphatically researched.On this base,the hydriding/dehydriding mechanism of NMCCM was studied.It was found that adding nickel powder to magnesium powder and crystallite carbon powder durning reaction milling under hydrogen is benefit for preparing NMCCM which is small size and have lower dehydriding temperature.The results showed that dehydriding temperature decreases as the contents of adding nickel increases,NMCCM 60Mg30C10Ni have the lowest dehydriding temperature which is 223.9℃.The results showed that dehydriding volume of NMCCM is dominated by the contents of adding nickel.As the contents of nickel increases,dehydriding volume enhances at low temperature,however,the reverse happens at high temperature.It was found that adding titanium dioxide powder to the powder of magnesium and crystallite carbon durning reaction milling under hydrogen atmosphere is bad for preparing small size NMCCM,when the contents exceed 20wt.%.As the contents increases but less than 20wt.%,the dehydriding volume of NMCCM becomes larger, when contents exceed 20wt.%,the reverse applies.The result showed adding nickel was benefit for separating,adsorbing hydrogen. So the hydriding raction was accelerated.Efficiency of reaction between magnesium grain and hydrogen was enhanced;separating and adsorbing hydrogen is the main function of titanium dioxide in the course of preparing NMCCM.更多还原