蓝藻基活性炭的制备及储氢性能研究

发布时间：2018-05-27 04:19

本文选题：蓝藻 + 活性炭　；参考：《华中科技大学》2015年硕士论文

【摘要】：氢能因具有可再生和无污染等特性而被认为是未来很有潜力的替代能源。氢气的储存是氢能应用的关键,高比表面积的活性炭是一种较有潜力的储氢材料。本论文以广泛存在于污染水体的蓝藻为原料,采用化学活化法制备了一系列的蓝藻基活性炭;通过BET、SEM、Boehm滴定等表征方法,探讨制备条件和表面化学改性对蓝藻基活性炭孔结构特性的影响,探讨孔结构特性及表面化学改性对蓝藻基活性炭储氢性能的影响。主要研究结论如下:(1)蓝藻的工业分析和元素分析表明,蓝藻所具有的特性,满足制备活性炭所需的基本要求。(2)直接活化法的实验结果表明,ZnCl2、KOH比H3PO4、NaOH更适合用来活化制备蓝藻基活性炭。(3)碳化活化法的实验结果表明,以ZnCl2为活化剂制得的蓝藻基活性炭的比表面积随着ZnCl2用量的增加而增加,随着活化温度的增加先降低后上升。以KOH为活化剂制得的蓝藻基活性炭的比表面积随着活化温度的增加而增加,随着KOH用量的增加先上升后下降,其最佳碱炭比为2。其中,ACK28的比表面积和孔体积最大,分别为1951 m2/g和1.092 cm3/g。(4)对ACK28进行化学改性研究发现,硝酸、磷酸改性后样品的比表面积和孔体积减小,而氨水改性后样品的比表面积和孔体积增加。(5)蓝藻基活性炭在77 K、1 bar下的储氢性能随着微孔体积和比表面积的增大而增大。其中,ACK28的储氢量最大,达1.73 wt%。硝酸、磷酸、氨水三种改性方法均利于蓝藻基活性炭对氢气的吸附,改性后样品的储氢性能受微孔体积、比表面积和表面化学性质的综合影响,且表面化学性质起主导作用。其中,氨水改性后样品的储氢量最大,达2.52 wt%,比改性前提高了46%。
[Abstract]:Hydrogen energy is regarded as a potential alternative energy source in the future because of its renewable and pollution-free properties. Hydrogen storage is the key of hydrogen energy application. Activated carbon with high specific surface area is a potential hydrogen storage material. In this paper, cyanobacteria widely existed in polluted water were used as raw materials, a series of cyanobacterium-based activated carbon was prepared by chemical activation method, and characterized by BET-SEMN Boehm titration. The effects of preparation conditions and surface chemical modification on pore structure characteristics of cyanobacterium-based activated carbon and the effects of surface chemical modification on hydrogen storage properties of cyanobacterial activated carbon were discussed. The main conclusions are as follows: (1) the industrial analysis and elemental analysis of cyanobacteria show that cyanobacteria have characteristics. The experimental results show that ZnCl _ 2 Koh is more suitable than H _ 3PO _ 4H _ 4 NaOH for the preparation of cyanobacterial activated carbon. The experimental results show that ZnCl _ 2 Koh is more suitable than H _ 3PO _ 4H _ 4O _ 4 NaOH for the preparation of cyanobacterial activated carbon. The specific surface area of cyanobacterium-based activated carbon prepared with ZnCl2 as activator increased with the increase of the amount of ZnCl2, and then increased with the increase of activation temperature. The specific surface area of cyanobacterium-based activated carbon prepared with KOH as activator increased with the increase of activation temperature, and then decreased with the increase of KOH content. The optimum ratio of alkali to carbon was 2. The specific surface area and pore volume of ACK28 were the largest (1951 m2 / g and 1.092 cm3 / g 路L ~ (4) respectively. The chemical modification of ACK28 showed that the specific surface area and pore volume of the samples modified with nitric acid and phosphoric acid decreased. However, the specific surface area and pore volume of the modified samples increased. 5) the hydrogen storage performance of cyanobacteria based activated carbon increased with the increase of micropore volume and specific surface area at 77Kg ~ (-1) bar. The hydrogen storage capacity of ACK28 reached 1.73 wts. Three modification methods, nitric acid, phosphoric acid and ammonia water, are beneficial to the adsorption of hydrogen on cyanobacterial activated carbon. The hydrogen storage performance of the modified samples is affected by the micropore volume, specific surface area and surface chemical properties, and the surface chemical properties play a leading role. The hydrogen storage capacity of the modified samples reached 2.52 wtt, which was 46 times higher than that before modification.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ424.1;TQ116.2

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