摘要
基于质子交换膜的固体聚合物电解质电解水制氢技术（PEM电解水技术）具有能效高、产氢纯度高、高压耐受性好、结构紧凑以及输入电力波动适应性强等优点，尤其适用于可再生能源电力电解制氢。目前限制PEM电解水技术产业化的主要因素为高成本（PEM，催化剂和双极板）以及析氧反应（OER）的高电位，尤其是昂贵的贵金属催化剂。针对这一问题，通过改进阳极催化剂IrO2的活性和稳定性有利于提升催化剂的性能与耐久性，进而达到节约贵金属用量降低成本的作用。
本文选取价格低廉、稳定性好、微结构可控性高的二氧化锡作为催化剂载体。针对其比表面积低、导电性差等不利于析氧反应（OER）的局限性，采用水热法，开展了Co掺杂对二氧化锡载体改性的研究。研究表明，Co掺杂可使所担载的IrO2颗粒细化，显著增加了IrO2组分的活性面积，同时加强掺杂的二氧化锡载体与IrO2颗粒之间的强交互作用，降低了Ir的价态，提升了复合催化剂的活性和耐久性。其中20 at%的Co掺杂可使比表面积增大至131.92 m2·g-1，使相应的复合催化剂40IrO2/Co0.2Sn0.8O2的导电性显著提升至1.17·100 S cm-1，且80 ℃下1 A·cm-2运行时最低槽电压为1.748V，可得出Co掺杂对催化活性的增强效果显著。
为了获得高稳定性和活性的析氧反应（OER）催化剂，本文采用表面改性/沉淀法合成了具有核壳结构的IrO2@RuO2析氧催化材料，该催化剂与商业RuO2和无载体IrO2的对比研究表明，核壳结构的IrO2@Ru
O2促使了两种氧化物的紧密接触，同时，覆盖RuO2表面上存在的分散良好的纳米颗粒IrO2，可以在界面电解质/催化剂处提供高浓度的活性位点，实现了RuO2固有活性和IrO2稳定性的协同效应，从而显示出最佳的活性。在单电池测试中，IrO2@ RuO2具有较无载体IrO2更低的槽电压，80 ℃下1 A·cm-2时仅为1.653 V，在300 h的耐久性测试中，前者表现出更佳的稳定性。因此，本论文有助于合理设计高效稳定的SPE析氧电极。
关键词：电解制氢；PEM电解池；析氧电极；氧化铱；二氧化锡；氧化钌
Abstract
The solid polymer electrolysis, which is mainly bad on the proton exchange membrane (PEM), has the advantages as high efficiency, high hydrogen purity, high pressure tolerance, compact structure, safety and environmental protection and good adaptability for fluctunt power, which make PEM water electrolysis quite suitbale for the conversion of the renewable energy power into hydrogen energy without carbon emission. The main factors of limiting the industrial application of the PEM water electrolysis are high system cost and relatively low durability, which mainly come from expensive catalyst. By improving the activity and stability of the anode catalyst IrO2, the compsite catalyst can obtain great enhancement on performance and durability, which contributes to the cost saving of the noble catalysts.
In this paper, tin dioxide was chon as the basic catalyst support becau of its low price, good stability, highly controllable microstructure. In order to overcome the disadvantages of tin dioxide on surface activity and conductivity, the hydrothermal method was ud to modify the tin dioxide support by Co doping. The rearch shows that Co doping refines the supported IrO2 particles, which was significantly incread the active area of the IrO2 component, at the same time, it also enhanced the strong interaction between the doped tin dioxide support and the IrO2 particles and reduces the valence state of Ir and enhances the activity and durability of the composite catalyst. The 20 at% Co-doped tin dioxide increas the specific surface area to 131.92 m2·g-1, and the conductivity of the composite catalyst 40IrO2/Co0.2Sn0.8O2is significantly improved to 1.17·100S cm-1.The composite catalyst performs a cell voltage of 1.748 V under 1 A·cm-2and 80 ℃, which shows that Co doping has a significant effect on the enhancement of catalytic activity.
In order to obtain high stability and active oxygen evolution reaction (OER) catalyst, a core-shell structure of IrO2@RuO2 oxygen evolution catalytic material was synthesized by surface modification/precipitation method. The comparative study of the IrO2@RuO2with commercial RuO2and unsupported IrO2shows that the core-shell structure of IrO2@RuO2promotes the intimate contact of the two oxides, and at the same time covers the well-defined small particles on the surfac
e of RuO2, which provide a high concentration of active sites at the interface electrol yte/catalyst. The catalytic benefic effects achieve a synergistic effect between the intrinsic
activity of RuO2 and the stability of IrO2 and thus show the best activity. As a result, the IrO2@RuO2 catalyst perform a cell voltage of 1.653 V under 1 A·cm-2 and 80 ℃, which successfully exceed the unsupported IrO2. Meanwhile, the IrO2@RuO2 catalyst shows better stability in the 300h durability test. Therefore, this paper is beneficial to design a suitable, high efficient and stable SPE oxygen evolution electrode.
Key words: Water electrolysis; PEM electrolysis; Oxygen evolution electrode; IrO2; tin oxide; RuO2
目录
学位论文原创性声明.................................................................................................. I 摘要........................................................................................................................ I I Abstract .................................................................................................................... III 插图索引................................................................................................................ V III 附表索引.................................................................................................................... X 第1章绪论 (1)
1.1电解水制氢技术研究现状 (1)
1.1.1碱性电解质电解技术 (1)
1.1.2 固体氧化物电解质电解技术 (2)
1.1.3 固体聚合物电解质电解技术 (3)
1.2 PEM电解反应原理 (5)
1.2.1 基本原理 (5)
1.2.2 热力学 (5)
1.2.3 电极反应动力学 (6)
1.3 PEM电极催化剂研究进展 (8)
1.3.1 阳极催化剂研究进展 (9)
1.3.2 阳极催化剂载体 (10)
世界因你而美丽1.4 本文研究内容 (12)
1.4.1 40IrO2/Co x Sn(1-x)O2新型催化剂的制备及研究 (12)
1.4.2 IrO2@RuO2新材料制备及研究 (12)
1.4.3 PEM电解池耐久性研究 (12)
第2章实验部分 (14)
2.1 实验材料与设备 (14)
2.1.1 实验材料 (14)
2.1.2 实验设备 (14)
2.2 样品制备 (15)
2.2.1 Co掺杂SnO2载体的制备 (15)
唐玄宗叫什么
2.2.2 负载型催化剂的制备 (16)
2.2.3 核壳IrO2@RuO2的制备 (17)
酒后喝什么
2.3.4 膜电极（MEA）组件制备 (18)
2.3 表征与分析方法 (19)
2.3.1 物理性能表征 (19)
2.3.2 半电池性能表征 (20)
我真了不起
2.3.3 单电池测试 (23)
三黄鸡炖土豆第3章Co掺杂二氧化锡载体的性能研究 (26)
急性跳远
3.1 Co掺杂对载体和复合催化剂结构的影响 (26)软推
3.1.1 晶相结构 (26)
3.1.2 载体介孔结构 (27)
3.1.3 导电性 (28)
3.2 载体Co掺杂对复合催化剂OER催化活性的影响 (29)
3.2.1 OER催化活性表征 (29)
3.2.1 显微与表面表征及载体作用分析 (31)
3.3 载体Co掺杂对复合催化剂单电池性能的影响 (33)
3.4 本章小结 (36)
第4章核壳IrO2@RuO2的性能研究 (37)
4.1 RuO2对复合催化剂结构的影响 (37)
4.1.1 晶体结构 (37)
4.1.2 TG-DSC分析 (38)
4.1.3 形貌分析 (39)
4.1.4 化学组成 (42)
4.2 RuO2对复合催化剂OER催化活性的影响 (43)
4.2.1 循环伏安法测试 (43)
4.2.2 稳定性测试 (46)
4.2.3 OER测试 (48)
4.3 RuO2对复合催化剂单电池性能的影响 (49)
4.4 本章小结 (51)
第5章MEA耐久性研究 (52)
5.1单电池耐久性测试 (53)
5.1.1不同催化剂的测试 (53)
5.1.1 IrO2@RuO2的单池耐久性分析 (55)
5.2 MEA阳极催化剂耐久性测试前后的形貌分析 (56)
5.2.1阳极催化剂性测试前后的形貌分析 (56)
不忘初心5.2.2 阴极催化剂耐久性测试前后的形貌分析 (57)
5.3 MEA的断面分析 (57)
5.3.1 IrO2作阳极的MEA耐久性测试前后的断面分析 (57)
5.3.2 IrO2@RuO2作阳极的MEA耐久性测试前后的断面分析 (60)
