硼掺杂介孔碳作为氧气还原电催化剂的研究

发布时间：2019-07-05 20:17

【摘要】：氧气还原反应(ORR)是燃料电池阴极上的重要过程,然而,其缓慢的动力学限制了燃料电池的性能,因此需要电催化剂来加速氧气还原反应。本论文以介孔碳作为催化剂,通过异原子硼(B)掺杂、硼和磷(P)共掺杂、硼和氮(N)共掺杂调控介孔碳的ORR的催化活性位。通过有序介孔结构的构筑,一方面提高介孔碳的比表面积,以增加催化活性位的数目;另一方面,改善三相界面区的氧气和电解液的传输,从而进一步促进氧气还原反应。采用溶剂蒸发诱导自组装法,以硼酸为B源,制备出B掺杂有序介孔碳,与未掺杂B的介孔碳相比,B掺杂介孔碳表现出明显提高的ORR催化活性。在B掺杂介孔碳的基础上,分别以磷酸和尿素作为P源和N源、硼酸为B源,以相同的制备方法合成了B和P、B和N共掺杂的介孔碳。系统研究了异原子掺杂种类、掺杂量、共掺杂异原子之间的前驱体比例和材料微观结构对ORR催化活性的影响,探讨了B掺杂、B和P共掺杂、B和N共掺杂介孔碳的ORR的催化机理,为设计、制备其它异原子掺杂碳的催化剂提供指导。
[Abstract]:Oxygen reduction reaction (ORR) is an important process on the cathode of fuel cell. However, its slow kinetics limits the performance of fuel cell, so it is necessary for electrocatalyst to accelerate the oxygen reduction reaction. In this paper, mesoporous carbon was used as catalyst to regulate the catalytic activity site of mesoporous carbon ORR by alloatomic boron (B) doping, boron and phosphorus (P) co-doping, boron and nitrogen (N) co-doping. Through the construction of ordered mesoporous structure, on the one hand, the specific surface area of mesoporous carbon is increased to increase the number of catalytic active sites; on the other hand, the transport of oxygen and electrolyte in the three-phase interface region is improved, so as to further promote the oxygen reduction reaction. B-doping ordered mesoporous carbon was prepared by solvent evaporation induced self-assembly with boric acid as B source. Compared with undoped B mesoporous carbon, B-doped mesoporous carbon showed obvious improvement in ORR catalytic activity. On the basis of B-doped mesoporous carbon, B and P, B and N co-doped mesoporous carbon were synthesized by the same preparation method using phosphate and urea as P source and N source and boric acid as B source, respectively. The effects of hetero-atom doping type, doping amount, precursor ratio and microstructure on the catalytic activity of ORR were studied systematically. The catalytic mechanism of B-doping, B and P co-doping, B and N co-doping mesoporous carbon ORR was discussed, which provided guidance for the design and preparation of other hetero-atom-doped carbon catalysts.
【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O643.36

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