二硫化物复合纳米催化剂的合成及其电析氢性能的研究

发布时间：2018-02-08 12:07

本文关键词： 电化学析氢反应二硫化钼二硫化钨多壁碳纳米管石墨烯　出处：《兰州大学》2017年硕士论文　论文类型：学位论文

【摘要】：氢能是最能替代化石燃料的可再生二次能源。电化学析氢是目前最主要的产氢方式。在众多的材料当中,铂族金属是最理想的析氢催化剂,但是它们价格昂贵并不适合广泛应用。因此,合成具有高活性和高稳定性的非贵金属阴极析氢催化剂是研究的重点。具有类似于石墨烯片层结构的二硫化物(MoS2和WS2)被认为是铂族金属的良好替代品,将其负载在具有良好导电性能的碳材料上制备催化剂并研究其析氢性能是本论文的主要研究内容。1.利用简单且温和的水热法合成出了以多壁碳纳米管为载体的系列电化学催化剂MWCNTs@MoxW1-xS2。通过TEM、XRD和XPS等手段对催化剂进行了表征。实验研究了不同Mo和W的摩尔比以及在MWCNTs上Mo0.54W0.46S2的负载量对于催化剂电化学析氢性能的影响,结果表明,MWCNTs@Mo0.54W0.46S2(Mo0.54W0.46S2的质量分数为77.3%)催化剂具有最好的析氢活性,其起始电位为-0.15 V vs.RHE,Tafel斜率为65 mV dec-1。同时,该催化剂在酸性介质中具有良好的析氢性能。2.首次利用冻干法,将MoS2量子点均匀地生长在石墨烯表面,合成了催化剂MoS2 QDs@GS。同时制备了不同形貌的MoS2@GS催化剂及具有不同摩尔比(MoS2 QDs:GS)的催化剂,并对催化剂进行了TEM、XRD和XPS等表征及电催化性能的测试。研究结果表明MoS2 QDs@GS3:1具有最佳的电化学析氢活性,它的起始电位为-0.094 V vs.RHE并且具有较大的阴极电流密度。电化学实验的结果表明,由上述两种方法所合成的析氢催化剂不仅具有大量活性位点,而且具有优异的电化学析氢活性(包括低的起始电位和塔菲尔斜率值以及大的阴极电流密度)。这为电化学析氢中非贵金属阴极催化剂的研究奠定了良好的基础。
[Abstract]:Hydrogen is the energy to replace fossil fuels and renewable energy two times. The electrochemical hydrogen evolution is the main way for hydrogen production. Among the many materials, platinum group metal hydrogen evolution is an ideal catalyst, but they are expensive is not suitable for wide application. Therefore, the synthesis of high activity and high stability and not expensive the metal cathode catalyst of hydrogen production is the focus of the study. It is similar to graphite structure two sulfide (MoS2 and WS2) is considered to be a good substitute for platinum group metals, which supported catalyst was prepared in carbon materials with good conductive properties and to study its hydrogen performance is the main research the content of.1. by a simple and mild hydrothermal method was synthesized by multi walled carbon nanotubes MWCNTs@MoxW1-xS2. carrier series electrochemical catalyst by TEM, the catalysts were characterized by XRD and XPS methods were experimentally investigated. Effect of different ratio of Mo and W and Mo0.54W0.46S2 loading on MWCNTs for the electrochemical hydrogen evolution properties of the catalysts. The results showed that MWCNTs@Mo0.54W0.46S2 (mass fraction of Mo0.54W0.46S2 is 77.3%) catalyst has the best catalytic activity of hydrogen evolution, the initial potential of -0.15 V vs.RHE, Tafel slope is 65 mV dec-1. at the same time, the catalyst has the properties of hydrogen analysis of.2. well in acidic medium by freeze dry for the first time, the MoS2 quantum dots to grow evenly on the surface of graphene, the catalyst MoS2 QDs@GS. was synthesized and prepared MoS2@GS catalysts with different morphologies and with different molar ratio (MoS2 QDs:GS) of the catalyst, and the catalyst was TEM, XRD and XPS characterization and the electro catalytic performance test. The results show that the MoS2 QDs@GS3:1 has the best electrochemical activity of hydrogen, it is -0.094 V the initial potential of vs.RHE and have greater Yin The drain current density. The results of electrochemical experiments showed that hydrogen catalyst synthesized by the two methods not only has a large number of active sites, but also has excellent electrochemical activity of hydrogen evolution (including initial potential and Tafel slope low value and high cathode current density). This has laid a good foundation for the study of non noble metal the cathode catalyst in the electrochemical hydrogen evolution.

【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TQ116.2

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