Pt@h-BN core–shell fuel cell electrocatalysts with electrocatalysis confined under outer shells

Two-dimensional (2D) materials such as graphene and hexagonal boron nitride (h-BN) can be used as robust and flexible encapsulation overlayers, which effectively protect metal cores but allow reactions to occur between inner cores and outer shells. Here, we demonstrate this concept by showing that Pt@h-BN core–shell nanocatalysts present enhanced performances in H₂/O₂ fuel cells. Electrochemical (EC) tests combined with operando EC-Raman characterizations were performed to monitor the reaction process and its intermediates, which confirm that Pt-catalyzed electrocatalytic processes happen under few-layer h-BN covers. The confinement effect of the h-BN shells prevents Pt nanoparticles from aggregating and helps to alleviate the CO poisoning problem. Accordingly, embedding nanocatalysts within ultrathin 2D material shells can be regarded as an effective route to design high-performance electrocatalysts.