摘要质子交换膜燃料电池以其洁净、高效的特点在未来极具应用前景，其 中 Pt 在 ORR 催化剂中占有重要地位，但是由于 Pt 的单价太高，所以直 接影响了运用 Pt 做催化剂的燃料电池的商业化，故寻找能够替代 Pt 的廉 价催化剂。通过人们不断地探索和研究，已经发现了许多新型的催化剂， 其中石墨烯作为一种新型纳米材料，拥有特殊的单原子层结构，使其拥 有丰富而特殊的性质。通过金属元素掺杂，可使其功能化，进而具有良 好的催化能力。二硫化钼具有和石墨烯相似的结构，通过研究掺杂不同 金属元素，对二硫化钼催化 ORR 反应的影响， 很有意义。本文利用 Materials Studio 软件，采用第一性原理的密度泛函理论，分别用金属（Ni， Pd，Pt，Ag）对二硫化钼进行面的 S 位掺杂，并分析作为 ORR 催化剂的 性能。通过分析氧气还原反应中间产物的吸附能和反应过程中发生的能 量变化，我们发现 S 位掺杂 Pt 二硫化钼催化剂符合吸附能不能太强以及 太弱的要求，并在 1。23V 的高电势下，具有着较低的热力学能垒，这表 明其只需要提供较低的能量，就能促使氧气还原反应的进行。在此，通 过掺杂，我们实现了功能化二硫化钼，并表明 S 位掺杂 Pt 二硫化钼催化 剂可应用于未来燃料电池阴极催化剂。84819
毕业论文关键词：金属掺杂二硫化钼 氧气还原反应 催化剂 第一性原理
Abstract Proton exchange membrane fuel cell (PEMFC) is very promising for the future application due to its non-pollution as well as the high efficiency。 Recently, Pt acts as the ORR catalysts to improve the sluggish reaction rate。 However, due to the high price and the scarcity, the Pt usage is hindered the PEMFC commercialization。 Therefore, it is desirable to find the alternative catalysts to replace Pt。 In the past decades, among the novel materials, the two-dimensional grapheme has gained our attention since its good capacity for catalysis。 By means of doping metal elements, the functional graphene possessed the superior ORR activity。 Similarly, since MoS2 has the same structure of the graphene, it is very meaningful to study the catalytic activity of the functional MoS2 with different metal doping in order to seek the efficient ORR catalyst。 In this paper, based on the simulation of Materials studio, using the density functional theory calculations, we systematic study the MoS2 catalyst with the transition metals (Ni, Pt, Pb,Ag) doping where fills the S vacancy in the inert facet are considered。 By calculating the adsorption energy of ORR intermediate, we find that Pt doped MoS2 catalyst possess the suitable adsorption ability。 Since the ORR catalyst must activate the O2 molecule and remove the oxide adsorbates, the adsorption energy of the optimal catalysts cannot be too strong or too weak。 Besides the adsorption
energy, the thermodynamic energy barriers of the ORR steps are considered。 At the potential of 1。23V, the Pt doped MoS2 has the lowest thermodynamic energy barrier among the other functional MoS2。 In a word, our results demonstrate that the Pt doped MoS2 catalyst is an excellent ORR catalyst。
Keywords: metal doped MoS2, oxygen reduction reaction, first-principle calculation
目 录
第一章 绪 论 1
1。1 能源及能源的分类 1
1。2 新能源概述 1
1。3 燃料电池的分类 2
1。4 氢氧燃料电池 2
1。4。1 燃料电池性能 4
1。4。2 燃料电池的长处与不足 MaterialsStudio二维硫化钼面活性研究:http://www.youerw.com/huaxue/lunwen_100946.html