碳基非铂复合催化剂的电催化析氢性能的研究
发布时间：2018-10-19 11:43
【摘要】：氢气是一种清洁、有效的、可循环利用的物质,可以高效的转变为可利用的有效能而不产生环境污染。在制氢的众多方法中,电解水制氢是目前最简便,最廉价,最洁净的制备方法,但由于析氢过电位的存在使得能耗增加。高效的析氢电极材料应该具有导电性好,析氢过电位低,电催化活性高以及电化学稳定性好等特点。为了提高阴极的电催化析氢活性,通常对电极表面进行设计、修饰,利用具有催化活性的催化剂修饰电极表面。Pt催化剂(Pt/C)被认为是目前催化效果最好的析氢反应催化剂,但成本高以及储量少限制了Pt催化剂的广泛应用。因此,非Pt阴极催化剂的研究越来越得到人们的关注。针对铂基催化剂的缺点,本论文制备了氧化钴/氮掺杂石墨烯和碳化物/碳两种非铂复合催化剂。1)以石墨烯为载体,采用微波辅助乙二醇还原法在石墨烯表面沉积纳米氧化钴颗粒,而后将其与三聚氰胺混和均匀,在N2气氛下在不同温度下热处理。结果表明,在600℃条件下制备的样品中CoO颗粒均匀地分布在褶皱的石墨烯表面,石墨烯的含氮量为8.6%,并且以其做催化剂的催化析氢反应活性最高。由Tafel曲线获得的动力学参数可知其具有小的起始电位、小的Tafel斜率和大的交换电流密度,并具有高的电化学稳定性,是一种有效的催化析氢反应的非铂催化剂,它比以相同的方法制备的以传统碳黑(XC-72)为载体的氧化钴/氮掺杂碳有更高的催化析氢反应活性。2)采用真空微蒸发镀法在870℃条件下加热传统碳黑(XC-72)和金属钼粉的混合粉末,成功在碳黑颗粒表面沉积碳化钼。结果表明,得到的样品是以Mo2C层包裹在碳黑颗粒表面的核壳结构,碳既作为载体材料,同时又作为合成复合材料的碳源。由Tafel曲线获得的动力学参数表明Mo2C/C复合催化剂具有较高的催化析氢反应活性和稳定性。
[Abstract]:Hydrogen is a clean, efficient, recyclable substance that can be efficiently converted to usable without environmental pollution. Among the many methods of hydrogen production, electrolytic water is the most convenient, cheapest and cleanest preparation method at present, but the energy consumption is increased due to the existence of hydrogen evolution overpotential. High efficiency hydrogen evolution electrode materials should have good conductivity, low hydrogen evolution overpotential, high electrocatalytic activity and good electrochemical stability. In order to improve the electrocatalytic hydrogen evolution activity of the cathode, the surface of the electrode is usually designed and modified, and the surface of the electrode is modified with the catalyst with catalytic activity. Pt catalyst (Pt/C) is considered to be the best catalyst for hydrogen evolution at present. However, high cost and less reserves limit the wide application of Pt catalysts. Therefore, the research of non-Pt cathode catalyst has been paid more and more attention. In view of the shortcomings of platin-based catalysts, two kinds of non-platinum composite catalysts, cobalt oxide / nitrogen doped graphene and carbides / carbon, were prepared in this paper. Nanocrystalline cobalt oxide particles were deposited on the surface of graphene by microwave-assisted ethylene glycol reduction method, and then mixed with melamine and heat treated at different temperatures in N2 atmosphere. The results showed that the CoO particles were uniformly distributed on the surface of folded graphene at 600 鈩，
本文编号：2281015
[Abstract]:Hydrogen is a clean, efficient, recyclable substance that can be efficiently converted to usable without environmental pollution. Among the many methods of hydrogen production, electrolytic water is the most convenient, cheapest and cleanest preparation method at present, but the energy consumption is increased due to the existence of hydrogen evolution overpotential. High efficiency hydrogen evolution electrode materials should have good conductivity, low hydrogen evolution overpotential, high electrocatalytic activity and good electrochemical stability. In order to improve the electrocatalytic hydrogen evolution activity of the cathode, the surface of the electrode is usually designed and modified, and the surface of the electrode is modified with the catalyst with catalytic activity. Pt catalyst (Pt/C) is considered to be the best catalyst for hydrogen evolution at present. However, high cost and less reserves limit the wide application of Pt catalysts. Therefore, the research of non-Pt cathode catalyst has been paid more and more attention. In view of the shortcomings of platin-based catalysts, two kinds of non-platinum composite catalysts, cobalt oxide / nitrogen doped graphene and carbides / carbon, were prepared in this paper. Nanocrystalline cobalt oxide particles were deposited on the surface of graphene by microwave-assisted ethylene glycol reduction method, and then mixed with melamine and heat treated at different temperatures in N2 atmosphere. The results showed that the CoO particles were uniformly distributed on the surface of folded graphene at 600 鈩，
本文编号：2281015
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