基于铌氢氧化合物复合材料的制备及其质子传导性能研究

发布时间：2018-05-25 19:25

  本文选题：质子导体 + 铌的氢氧化合物　； 参考：《东北师范大学》2017年硕士论文

【摘要】：随着质子交换膜燃料电池研究领域的飞速发展,简化制备方法开发合成新型低成本的质子传导电解质材料仍然具有一定的挑战性。由于材料的电导率受到载体和电荷的数量影响较大,因此,具有丰富电荷和质子载体的材料可被认为是一种有效的质子导体材料。例如多金属氧酸盐是一类典型的过渡金属氧化物簇,作为质子导体,其本身可以提供质子,结构中存在的大量水分子可作为质子载体,而且多金属簇表面富含氧原子,也可作为质子的跳跃位点,从而为质子的传输提供一条通路。近年来,一种基于过渡金属氢氧化合物(MOx(OH))的新型非晶态纳米材料因具有独特的性能而引起人们广泛关注,该结构中含有丰富的羟基基团,能有效构筑氢键网络,因而利于质子跳跃。另外,在结构中引入磺酸、磷酸、羧基等一些含氧功能性基团也能在一定程度上提高质子传导效率。本论文的研究主要包含以下两个方面:1.以五氯化铌为原料,通过简便的溶胶-凝胶法水解合成了一种基于金属铌的氢氧化合物NbOx(OH)-Cl,将其作为一种新型的质子导体材料,同时引入一种富含质子载体的多金属氧酸盐(磷钨酸)形成了一种富含羟基且具有三维氢键网络结构的复合质子导体材料NbHyOx(OH)-PW12。结果表明,掺入多酸的复合材料NbHyOx(OH)-PW12比单纯的NbOx(OH)-Cl表现出更高的质子电导率,数据显示在25℃,97%相对湿度条件下,NbHyOx(OH)-PW12的电导率值可达到6.52 mS cm-1,比同条件下NbOx(OH)-Cl的性能提升了4个数量级。最后,我们对掺杂剂比例不同对样品性能的影响进行了分析,对比结果显示当Nb:{PW12}摩尔比达到67:1时,材料能够表现出相对较高的质子传导效率。2.在铌的氢氧化合物骨架中引入植酸分子(Phytic acid,以下简写为PA),通过溶胶-凝胶法原位合成了一种富含羟基和磷酸功能性基团的植酸掺杂的铌的氢氧化合物NbHyOx(OH)-PA,并研究了其作为质子导体的性能,实验结果表明当Nb:PA的摩尔比达到17:1时,材料在75℃,97%相对湿度条件下可达到最高的电导率(9.8 mS cm-1)。
[Abstract]:With the rapid development of proton exchange membrane fuel cell (PEMFC) research, it is still challenging to develop and synthesize new proton conductive electrolyte materials by simplified preparation method. Because the conductivity of the material is greatly affected by the number of carriers and charges, the materials with rich charge and proton carrier can be considered as an effective proton conductor material. For example, polyoxometalates are a kind of typical transition metal oxide clusters. As proton conductors, polyoxometalates can provide protons themselves. A large number of water molecules in the structure can be used as proton carriers, and the surface of polymetallic clusters is rich in oxygen atoms. It can also be used as a jumping site for protons, thus providing a pathway for proton transport. In recent years, a novel amorphous nanomaterials based on transition metal hydroxides (MOXO) have attracted much attention because of their unique properties. The structure contains abundant hydroxyl groups and can effectively construct hydrogen bond networks. So it's good for proton jumping. In addition, the introduction of sulfonic acid, phosphoric acid and carboxyl groups into the structure can improve the proton conduction efficiency to some extent. The research of this thesis mainly includes the following two aspects: 1. Using niobium pentachloride as raw material, a niobiobium-based hydrogen compound NbOxOH- Cl-Cl was synthesized by a simple sol-gel method, which was used as a new proton conductor material. At the same time, a proton rich polyoxometalate (phosphotungstic acid) was introduced to form a hydroxyl rich composite proton conductor material NbHyOxOHN-PW12 with a three-dimensional hydrogen bond network structure. The results show that the proton conductivity of polyacid-doped composite NbHyOx(OH)-PW12 is higher than that of pure NbOx(OH)-Cl. The data show that the conductivity of NbHyOxOHM-PW12 can reach 6.52 mScm-1 at 25 鈩，

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