多孔骨架限域担载超低铂燃料电池催化剂研究

As an energy conversion device, proton exchange membrane fuel cells (PEMFCs) are received more and more considerations due to its high efficiency and low pollution. However, the costly Pt/C is still the most popular oxygen reaction reduction (ORR) catalyst at cathode so far. The relatively high Pt loadings and lower durability at the working environment have being severely hindered the commercialization of the PEMFC. Therefore, it is urgent to explore a Pt based electrocatalyst with a low loading, an excellent durability and high efficiency for ORR. In this application, we design a three dimensional mesoporous carbon framework which confined Pt nanoparticles from migration and aggregation as an excellent electrocatalyst (Pt@MCF) for ORR via employing Pt wrapped into ZIF-8 (Pt@ZIF-8). With such an unique structure, the Pt@MCF not only allowed to access the electrolyte to the Pt surface as a result of the porous structure, thus the utilization of Pt is promoted, but also effectively prevented the Pt nanocrystals from detachment, dissolution, migration, and aggregation during working condition. Therefore, the problems with the high loading and stability of Pt-based catalyst can be expected to be solved through this project’s investigation.

燃料电池作为一种高效的、绿色的能源转换装置越来越受到人们的关注。然而，目前燃料电池的阴极氧还原（ORR）催化剂依然使用的是价格昂贵的Pt/C催化剂。因此，迫切需要研发一种低载量、高稳定、高活性的Pt基催化剂。 本申请提出利用金属有机框架ZIF-8的生长机理，将事先制备好的Pt颗粒限域担载在ZIF-8中，通过调控前驱体的种类、Pt的加入时间、烧结工艺等手段，制备一种三维的介孔骨架碳材料（MCF）限域担载Pt的催化剂。该催化剂丰富的介孔结构可以充分提高Pt的利用率，从而使Pt在较低的载量情况下，依然表现出很好的催化活性。另外，该催化剂还可以使Pt完全分散在介孔碳骨架网络内部，从而避免了Pt/C催化剂所面临的Pt颗粒的团聚、熟化等稳定性退化的问题。

燃料电池作为一种高效的、绿色的能源转换装置越来越受到人们的关注。然而，目前燃料电池的阴极氧还原（ORR）催化剂依然使用的是价格昂贵的Pt/C催化剂。因此，迫切需要研发一种低载量、高稳定、高活性的Pt基催化剂。在本项目支持下，利用金属有机框架结构ZIF-8为模板，制备出一种具有高比表面积的氮掺杂介孔碳材料（N-MCF），当以此为载体，所制备的Pt/N-MCF催化剂与商业Pt/C性对比，表现出优良的氧化还原（ORR）活性和稳定性。为进一步提高所制备Pt-基催化剂的ORR活性和稳定性，我们利用ZIF-8和ZIF-67的生长机理，提出了限域包覆Pt纳米颗粒的思想，制备出Pt@N-MCF和PtCo@CNTs-MOF两种低Pt催化剂，该催化剂不仅表现出优良的ORR活性和稳定性，而且单电池测试表明，在非常低的Pt用量的情况下，其功率输出性能远高于商业Pt/C催化剂。.