硅基复合物水解制氢性能的研究

发布时间：2018-02-11 20:17

  本文关键词： 水解制氢性能 硅 添加剂 球磨　出处：《浙江大学》2017年硕士论文　论文类型：学位论文

【摘要】：硅具有理论氢容量高、价格低廉和资源丰富等优点,被认为是一种很有前景的新型水解制氢材料,可以应用于便携式氢源或燃料电池系统中。但是硅单独与纯水反应水解制氢速率极慢,产氢量低,制约了它的应用。为了提高硅的水解制氢活性,本文(1)采用球磨方法制备了 Si/LiH(LiBH4)复合物,并在此基础上添加NiC12制备了三元复合物,系统研究了复合物的水解制氢特性;(2)采用化学法制备了多孔硅,并研究了多孔硅的水解制氢性能;(3)研究了硅及其复合物在碱性环境中的水解性能,研究了 Si/LiBH4复合物在KOH溶液中水解的协同作用;并采用XRD、SEM、BET、XPS等测试方法对样品进行了表征,对相关机理进行了初步分析。首先本文研究了球磨后的硅、及硅基复合物在常温下的水解性能。实验结果表明,在硅中添加LiH或LiBH4制备Si/LiH(LiBH4)复合物可以提高其水解制氢的产量、初始放氢速率。在室温下水解1小时,二元Si/10%molLiH复合物产氢量约为37mL/g,Si/10%molLiBH4水解产氢容量可达126mL/g,三元的Si-10%molLiH-3%molNiC12复合物水解产氢容量可达119mL/g,是硅单独水解产氢量的12倍。接着本文探索了多孔硅的制备,并研究了多孔硅在常温下的水解性能。实验结果表明,腐蚀时间为5小时的多孔硅在常温下水解1小时的制氢产量为20.5mL/g;提高温度和在水解溶液中添加适量酒精可以提高多孔硅的水解产氢量,在65℃时,多孔硅在酒精与水的混合溶液中水解制氢产量可达37.5mL/g。最后,本文系统研究了硅在KOH溶液中的水解制氢性能。实验结果显示,硅在KOH溶液中的水解制氢产量规律随KOH的量和浓度都是先升高后降低,在摩尔比Si:KOH=1:2,KOH的浓度为15wt%时,硅在常温下水解1小时的水解制氢产量可以达到85%。值得一提的是,当摩尔比Si:KOH=1:0.5时,Si-3mol%LiBH4复合物常温下在浓度为10wt%的KOH溶液中水解1小时的水解制氢产率为72.5%,远高于未掺杂LiBH4的硅,这可能是LiBH4的水解与硅的水解发生了协同作用,使得复合物较硅的水解制氢产量提升了 100%。
[Abstract]:Silicon has the advantages of high theoretical hydrogen capacity, low price and abundant resources, so it is considered as a promising new hydrolytic hydrogen production material. It can be used in portable hydrogen source or fuel cell system. However, the rate of hydrogen production is very slow and the hydrogen production is low. In this paper, Si / LiH- LiBH4) complexes were prepared by ball milling, and ternary complexes were prepared by adding NiC12. The hydrolytic hydrogen production properties of the complexes were systematically studied. Porous silicon was prepared by chemical method. The hydrolytic properties of porous silicon and its complexes in alkaline environment were studied, and the synergistic effect of Si/LiBH4 complex hydrolysis in KOH solution was studied, and the samples were characterized by XRD-SEMBET-XPS. The mechanism was analyzed. Firstly, the hydrolytic properties of ball-milled silicon and silicon-based composites at room temperature were studied. Initial hydrogen release rate. Hydrolysis at room temperature for 1 hour, The hydrogen production capacity of binary Si/10%molLiH complex is about 37 mL / g / 10 and the hydrolysis capacity of Si-10%molLiH-3%molNiC12 complex can reach 126 mL / g, and the hydrolysis capacity of ternary Si-10%molLiH-3%molNiC12 complex can reach 119 mL / g, which is 12 times as much as that of silicon alone. The hydrolysis properties of porous silicon at room temperature were studied. The hydrogen production of porous silicon with corrosion time of 5 hours hydrolyzed for 1 hour at room temperature is 20.5 mL / g, and the hydrogen production of porous silicon can be increased by increasing the temperature and adding a proper amount of alcohol in the hydrolytic solution, at 65 鈩，

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