State Key Laboratory of Chemical Resource Engineering, School of Science, Beijing University of Chemical Technology, Beijing 100029, P. R. China
Abstract:
Proton exchange membrane fuel cells (PEMFCs) are considered as ideal alternative power devices to traditional internal combustion engines for automobile applications because of their high electric power density, high energy conversion efficiency, and low environmental impact as well as low temperatures for start-up and operation. However, PEMFCs normally require a high loading of the expensive precious metal platinum (Pt) as the electrocatalytic material to maintain desirable energy output. Thus, the development of novel catalysts with lower Pt loading, enhanced activity, and improved durability is vital for the scalable commercialization of PEMFC technology. In this regard, core-shell structure has been demonstrated as an effective strategy to minimize the amount of Pt in PEMFCs because of the following two factors:(1) a core-shell architecture with a Pt-rich shell and M-rich (M represents an earth-abundant element) core can greatly improve the utilization of Pt; (2) the activity and stability of Pt on the surface can be greatly enhanced by strain (geometry) and electronic (alloying) effects caused by the M in the core. First, we briefly discuss the structure-performance relationship of typical core-shell structured electrocatalysts for the oxygen reduction reaction (ORR). Then, we review the development of Pt-based core-shell structured catalysts for the ORR. Finally, a perspective on this research topic is provided.
