质子交换膜燃料电池高效低铂核壳催化剂稳定性强化设计制备

This project focuses on degisning highly stable core-shell catalysts with low Pt loading for fuel cells. Core-shell catalyst with Pt-shell structure is the best way to achieve low-cost fuel cell catalysts. However, the insufficient stability of the current core-shell catalysts leads to the severe performance degration of catalysts and fuel cells. Thus, it is focused on searching stable metal or metal-based alloys and novel stable materials as cores, and studying the electronic effect and ligand effect of core on Pt shell, the synergetic interactions between core and shell. The dependence of catalytic stability and activity on the surface structure and electronic property will be studied. The preparation method and the property gap of core and shell will be employed to tune the catalyst structure and the cosequent catalytic performance, based on wich the relationship between strutures of catalysts and catalytic stability will be investigated. The object is to find stale and cost-effective core-shell catalysts, and then designing and preparing the correponding core-shell catalyst with optimal components and structures.It is expected that the novel path for boosting catalytic stability could be proposed, which could guide the preparation of stable core-shell catalysts with low Pt loading.

本申请着力于设计制备稳定可靠的燃料电池低Pt核壳催化剂。核壳结构是实现催化剂低Pt载量、降低燃料电池成本的有效途径。针对现有燃料电池核壳催化剂的稳定性不足现象，拟通过选择稳定的内核金属或多金属合金以及新型稳定的内核材料等方式，利用内核材料对壳层贵金属Pt的电子效应与配体效应、壳层双组分间的协同效应等方面研究催化剂结构、表面电子性质与催化行为三者之间的关系，考察制备方法，核壳材料性质差异等引起的催化剂结构以及电催化性能的变化，深刻理解催化剂活性稳定性和催化剂组成结构之间的关系。筛选出长效高稳定性的低Pt核壳催化体系。综合考虑影响催化剂稳定性的各种物理化学因素，对所选体系组成结构进行优化和理性设计以及控制制备，提出提高催化剂稳定性的新途径，为制备高稳定性的低Pt核壳催化剂提供理论依据。

本项目获批以来始终围绕着稳定的核壳催化剂的理性设计、制备、与构效关系展开研究工作。在阳极，探索了系列具有新颖结构、超高活性与稳定性的催化剂合成方法，制备了具有核壳结构的PtM零维与一维催化剂，用于燃料电池的阳极电氧化过程。在燃料电池阴极，合成了具有Pt骨架结构的Pt@PtM型催化剂，利用应力效应和配体效应的共同作用提升催化性能，并确保催化剂的高稳定性。同时，通过调变载体的电子结构改善其对催化剂的锚定效果，进一步提升催化剂的稳定性。系统的研究了系列催化剂的电催化行为，探讨了催化剂结构、表面电子性质与催化行为三者之间的关系。已获得系列控制合成具有长效高稳定的低Pt 核壳催化剂的新方法，理解了催化剂表面性质与结构参数对催化剂活性尤其是稳定性提升的作用方式与过程，揭示了组成和结构对性能的影响规律，确定了核壳催化剂的最优组成和表面状态，为制备高稳定性的低Pt核壳催化剂提供理论依据。