过渡金属氮化物/铂核壳结构催化剂的原位制备及其膜电极性能研究

Reducing platinum loading of fuel cells is of great significance for the development of fuel cell technology and large-scale commercialization, which is the most important topic in the research field of fuel cells. Since Pt utilization efficiency and cell performance of membrane electrode assembly are both limited by traditional fabrication approach, this project proposes an in-situ deposition strategy for an ultra-low platinum-loading membrane electrode assembly based on a transition metal nitride/platinum core-shell catalysts. In-situ growth of the nitride/platinum core-shell catalysts within electrode is realized by the direct deposition technique, and the low Pt utilization efficiency due to the random distribution of the catalysts in the conventional electrode can be fully avoided.The effect of composition and structure of nitride composite, solvent, deposition composition, deposition process and Pt shell thickness on the cell performance are investigated. Through performance evaluation and structure characterization, the deposition mechanism of platinum on the surface of nitride nanoparticles and its interaction between core and shell can be explored and identified. Meanwhile, the catalytic mechanism and fuel, electron and proton transfer mechanism of the ultra-low platinum-loading membrane electrode assembly will be established. This project will shed light on the development of high performance and ultra-low Pt loading membrane electrode assembly for fuel cell application.

降低燃料电池的铂载量对于燃料电池技术的发展及大规模商业化具有十分重要的意义，相关研究为燃料电池领域的最为重要方向之一。针对传统膜电极制备在提升铂利用率和性能方面存在的局限性，本项目提出了一种基于过渡金属氮化物/铂核壳结构催化剂的超低铂载量膜电极的原位制备策略。利用直接沉积技术，实现电极内氮化物/铂核壳结构催化剂原位生长，避免传统电极中因催化剂随机分布而导致的较低利用率。研究氮化物基体的组成及结构、溶剂及沉积液组成、沉积工艺、铂壳层厚度等对于膜电极性能的影响及其规律，从而制备出新型高性能超低铂载量膜电极；通过性能评价和表征，探索和阐明铂在氮化物纳米粒子表面的沉积机理及其壳核相互作用，阐明新型超低铂载量膜电极的催化作用机理及物料、电子、质子传递机理，为高性能超低铂载量膜电极的开发制备提供新的技术路线和科学支撑。

本项目利用电化学沉积技术，在不同的过渡金属掺杂的一元/二元氮化物表面，实现了超低载量的Pt纳米颗粒的可控制备。通过调控载体的组成、大小及形貌，进而调控Pt壳层的沉积厚度，从而通过改变表界面电子结构来促进催化剂的电化学性能和稳定性。在此基础上，通过多种表征手段和电化学性能测试，详细研究了 Pt 在不同过渡金属氮化载体表面的沉积机理及其之间的电子相互作用，并结合单电池测试对过渡金属掺杂的氮化材料进行性能和稳定性测试和评估，揭示催化作用及电极失效机理。