论文总字数：23901字

摘 要

氢能是一种对可持续并且环境友好的能源，可以有效的改善当前的能源危机。MgH₂作为一种新型储氢材料，具有无污染（燃烧产物只有水）、理论储氢量高（7.6 wt.%）、含量丰富、价格低廉等优点，非常适用于推进氢能的循环利用。但是实际上MgH₂本身的热力学性能稳定，放氢动力学性能十分迟缓，是其实际运用上的阻碍。基于以上原因本实验结合外加催化剂和机械球磨的方法，对MgH₂的吸放氢性能进行改善。我们通过液相法将具有催化性能的Ni与二维层状材料Ti₃C₂(FL)进行复合，并且通过机械球磨法将其引入了MgH₂，制备得到了MgH₂ 5 wt.% Ni/Ti₃C₂(FL)样品。采用XRD、XPS对催化剂的制备过程进行了深入的探究，同时采用PCT探究了MgH₂ 5 wt.% Ni/Ti₃C₂(FL)的吸放氢性能。结果显示MgH₂ 5 wt.% Ni/Ti₃C₂(FL)的脱氢峰值温度在302 ℃；在275 ℃下600 s内放氢量可以达到6.5 wt.%；在125 ℃下3500 s内吸氢量达到6.3 wt.%。通过阿伦尼乌斯方程计算，发现MgH₂ 5 wt.% Ni/Ti₃C₂(FL)的脱氢表观活化能为99.36 kJ/mol H₂，相比于商业版的MgH₂（153 kJ/mol H₂）下降了53.64 kJ/mol H₂；其吸氢表观活化能为41.36 kJ/mol H₂，相比于商业版的MgH₂（71 kJ/mol H₂）下降了29.64 kJ/mol H₂。Ni/Ti₃C₂(FL)的引入显著改善了MgH₂的储氢性能，表现了良好的催化性能。

关键词：镁基储氢材料 镍基催化剂 MXene

Few layers Ti₃C₂T_x supported nano-nickel via self-assembly reduction on hydrogen storage performance of MgH₂

Abstract

Hydrogen energy is a sustainable and environmentally friendly energy source, which can effectively ease the current energy crisis. As a new type of hydrogen storage material, MgH₂ has the advantages of no pollution (the combustion product is only water), high theoretical hydrogen storage (7.6 wt.%), rich content, and low price. It is very suitable for promoting the recycling of hydrogen energy. But in fact, the thermodynamic performance of MgH₂ itself is stable, and the kinetic performance of hydrogen evolution is very slow, which are an obstacle to its practical application. Based on the above reasons, this experiment combined with the introduction of catalyst and ball milling method under argon atmosphere to improve the hydrogen absorption and desorption performance of MgH₂. We combined Ni and two-dimensional layered material Ti₃C₂ (FL) by liquid phase method, and introduced it into MgH₂ by mechanical ball milling method, and prepared MgH₂ 5 wt.% Ni/Ti₃C₂(FL) sample. The preparation process of the catalyst was studied by XRD and XPS. At the same time, PCT was used to investigate the hydrogen absorption and emission performance of MgH₂ 5 wt.% Ni/Ti₃C₂(FL). The results show that the peak dehydrogenation temperature of MgH₂ 5 wt.% Ni/Ti₃C₂ (FL) is 302 ℃; 6.5 wt.% hydrogen is released at 600 s at 275 ℃; and 6.3 wt.% hydrogen is absorbed at 3500 s at 175 ℃. The calculation via Arrhenius equation finds that the apparent activation energy of dehydrogenation of MgH₂ 5 wt.% Ni/Ti₃C₂ (FL) is 99.36 kJ/mol H₂, which is 53.64 kJ/mol H₂ lower than that of the commercial MgH₂ (153 kJ/mol H₂). The apparent activation energy of hydrogen absorption is 41.36 kJ/mol H₂, which is 29.64 kJ/mol H₂ lower than that of the commercial MgH₂ (71 kJ/mol H₂). The introduction of MgH₂ 5 wt.% Ni/Ti₃C₂ (FL) significantly improves the hydrogen storage performance of MgH₂ and shows good catalytic performance.

Key Words: Magnesium based hydrogen storage material; Ni-based catalyst; MXene

目 录

摘 要 I

Abstract II

第一章 绪论 1

1.1 氢能源研究背景 1

1.1.1固态储氢 2

1.2 镁基储氢材料概况 3

1.2.1 MgH₂吸放氢原理 3

1.2.2 过渡金属元素催化提高镁基储氢材料的性能 4

1.2.3 合金化提高镁基储氢材料的性能 6

1.2.4 纳米化提高镁基储氢材料的性能 6

1.3 MXene（Ti₃C₂）材料概况 7

1.3.1二维层状材料MXene在LiBH₄中的催化应用 8

1.3.2二维层状材料MXene在NaAlH₄中的催化应用 8

1.3.3二维层状材料MXene在MgH₂中的催化应用 9

1.4 课题的提出及本文研究内容 9

第二章 实验部分 10

2.1 实验所用试剂及器材 10

2.2 实验所用到的仪器 10

2.3 样品制备 10

2.3.1 制备Ti₃C₂T_x (FL)胶体溶液 11

2.3.2 Ti₃C₂T_x(FL)掺杂Ni的合成 11

2.4实验工艺 11

2.4.1氢化燃烧合成法 11

2.4.2机械球磨法 12

2.5材料测试与性能 12

2.5.1 PCT 测试 12

2.6 微观形貌表征 12

第三章 实验结果与分析 14

3.1含有不同质量分数的镍的催化剂的XRD图谱 14

3.2 MgH₂ 5 wt.% Ni/Ti₃C₂(FL)样品的放氢分析 16

3.2 MgH₂ 5 wt.% Ni/Ti₃C₂(FL)样品的吸氢分析 20

第四章 结论与展望 23

4.1 结论 23

4.2 展望 23

参考文献 25

致谢 28

第一章 绪论

请支付后下载全文，论文总字数：23901字