质子交换膜燃料电池中Pt/C及Pt合金/C催化剂的衰退机制研究综述

Review on the Decay Mechanism of Pt/C and Pt-alloy Catalysts in PEM Fuel Cells

成本和耐久性依然是制约质子交换膜燃料电池商业化发展的两大瓶颈。首先综述了质子交换膜燃料电池阴极Pt/C催化剂在实际工作条件下的降解情况,并给出了可能的降解机制。结果表明,Pt/C催化剂在实际工作条件下,尤其是在汽车应用中是不稳定的,通常无法用作燃料电池阴极催化剂。而Pt合金催化剂因具有优异的氧还原催化性能和相对较好的耐久性,被认为有望解决成本和耐久性这两大难题,因此在质子交换膜燃料电池中日益得到重视和应用。但如何改善合金催化剂的耐久性依然是一个棘手的问题,文章最后详细综述了PtxCoy合金催化剂可能的衰退机理,以及可在一定程度上提高Pt合金催化剂耐久性的Pt单层结构和Pt核壳结构,这对催化剂的合成和设计具有一定的指导意义。

Cost and durability of PEM fuel cells are still two bottlenecks that impede the commercialization of PEM fuel cells. Initially, the degradation of the Pt/C catalyst for the proton exchange membrane fuel cell cathode under practical working conditions is reviewed and possible degradation mechanisms are given. The results indicate that the Pt/C catalyst is not stable under practical working conditions, especially in automotive applications, and cannot meet the practical requirements of cathode materials for PEM fuel cells. Pt alloy catalysts are expected to solve the problems of cost and durability due to their excellent oxygen reduction catalytic properties and relatively good durability. Therefore, they have been paid more and more attention and applied in PEM fuel cells. However, the durability of the alloy catalyst is still a difficult problem. At the end of this paper, the possible mechanism of the PtxCoy alloy catalysts degradation is reviewed and it is found that Pt monolayer structure and Pt skeleton structure can improve the durability of Pt alloy catalysts, which has a directive significance for the synthesis and design of catalysts.