三氢化铝干法合成工艺研究
发布时间：2018-12-09 17:24
【摘要】：传统化石能源的日趋消耗及其使用过程中引发的诸多环境污染问题越来越受到人们的广泛关注,人们迫切需要找到一种可再生、清洁能源。氢能以资源丰富、环保性能好以及经济效益高等优点逐渐得到大家的青睐,而储氢却成为氢能源开发与利用的瓶颈。AlH3是典型的金属储氢材料,因其具有优越储氢性能——高理论储氢体积和储氢密度,而被视为最有发展和应用前景的优质储氢材料,在储氢材料领域备受人们关注。本论文提出了Al H3的干法合成法,在避免了液相合成法的缺点同时,也克服了直接合成法的限制性因素,主要研究内容:利用机械球磨法制备活性很高、晶粒非常小的铝粉,使用TG、SEM和XRD对球磨得到的铝粉进行表征;实验结果表明该活性铝粉初始增重温度是280℃,最大氧化速率是3.43 mg/min,平均晶粒尺寸是20.1 nm;在溶剂甲苯中制备催化剂R2AlH(R代表烷基),利用LiAlH4和Et2AlCl作原料,在95℃下反应5 h制备生成Et2AlH;利用LiAlH4与Me3Al作原料,在85℃条件下反应3 h制备生成Me2AlH,对制备得到的产物进行核磁共振表征(1H NMR),核磁谱图分析表明采用以上实验方法可以制备生成的Et2AlH与Me2AlH,并且二者的纯度较高。研究使用二异丁基氢化铝、二乙基氢化铝和二甲基氢化铝催化活性铝粉与氢气反应,通过控制反应温度(90~120℃)和时间(8~12h)进行AlH3合成实验;对实验生成的产物分别进行XRD表征,实验结果表明使用三种R2AlH催化活性铝粉与氢气均可以生成AlH3;利用放氢实验装置分别对产物进行放氢实验,由实验结果可知三种催化反应中AlH3产率分别为0.90%、1.25%和2.76%;根据催化反应条件及产物产率可知,催化剂活性大小顺序为二甲基氢化铝、二乙基氢化铝、二异丁基氢化铝。采用低热固相法,以LiAlH4与AlCl3作反应原料,探究反应温度(65~95℃)、时间(2~5h)以及原料摩尔比(4:1~12:1)对合成AlH3的影响;反应产物的XRD表征分析结果表明:当LiAlH4与AlH3摩尔比大于4:1,反应温度高于75℃,反应时间大于2 h时,采用低热固相法可以获得AlH3;XRD表征结果与放氢实验结果表明低热固相法合成AlH3的最优条件为LiAlH4与AlH3摩尔比为9:1,反应温度为85℃,反应时间为4 h,在此反应条件下AlH3产率为24.0%。。
[Abstract]:People pay more and more attention to the increasing consumption of traditional fossil energy and many environmental pollution problems caused by its use. People urgently need to find a kind of renewable and clean energy. Hydrogen energy is getting more and more popular because of its rich resources, good environmental performance and high economic benefit, while hydrogen storage has become the bottleneck of hydrogen energy development and utilization. AlH3 is a typical metal hydrogen storage material. Because of its superior hydrogen storage properties, such as high theoretical hydrogen storage volume and hydrogen density, it is regarded as the most promising high quality hydrogen storage material, which has attracted much attention in the field of hydrogen storage materials. In this paper, a dry synthesis method of Al H3 is proposed, which avoids the shortcomings of liquid phase synthesis and overcomes the restrictive factors of direct synthesis. The main research contents are as follows: preparation of aluminum powder with high activity and very small grain by mechanical ball milling method. The Al powder prepared by ball milling was characterized by TG,SEM and XRD. The experimental results show that the initial weight gain temperature is 280 鈩，
本文编号：2369753
[Abstract]:People pay more and more attention to the increasing consumption of traditional fossil energy and many environmental pollution problems caused by its use. People urgently need to find a kind of renewable and clean energy. Hydrogen energy is getting more and more popular because of its rich resources, good environmental performance and high economic benefit, while hydrogen storage has become the bottleneck of hydrogen energy development and utilization. AlH3 is a typical metal hydrogen storage material. Because of its superior hydrogen storage properties, such as high theoretical hydrogen storage volume and hydrogen density, it is regarded as the most promising high quality hydrogen storage material, which has attracted much attention in the field of hydrogen storage materials. In this paper, a dry synthesis method of Al H3 is proposed, which avoids the shortcomings of liquid phase synthesis and overcomes the restrictive factors of direct synthesis. The main research contents are as follows: preparation of aluminum powder with high activity and very small grain by mechanical ball milling method. The Al powder prepared by ball milling was characterized by TG,SEM and XRD. The experimental results show that the initial weight gain temperature is 280 鈩，
本文编号：2369753
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