A review of core-shell nanostructured electrocatalysts for oxygen reduction reaction

In this paper, the current technological state of core-shell nanostructured catalysts is reviewed for oxygen reduction reaction (ORR). The advantages of core-shell catalysts over alloyed ones are discussed and their achievements are summarized. Various core-shell electrocatalysts with advanced nanostructures have shown remarkable activity and stability, demonstrating great potential in proton exchange membrane (PEM) fuel cell applications. The dissolution of core and shell as well as low structure retention in fuel cell operating environments can cause catalyst degradation, which is a major challenge and remains such. To facilitate further efforts in new catalyst development, several research directions are proposed in this paper.