Enhancing the oxygen reduction activity by constructing nanocluster-scaled Fe 2 O 3 /Cu interfaces.

Interface engineering is a promising strategy to enhance the catalytic performance of electrocatalysts for the oxygen reduction reaction (ORR). However, it is still a challenge to modulate the size into a suitable range ( e.g. , nanocluster-scale) to make the most of the interface. Moreover, the explicit mechanism of the interface for enhancing catalytic performance is still elusive. Herein, a model catalyst (FeCu@NC) loaded with nanocluster-scaled Fe 2 O 3 /Cu interfaces was prepared by modulating the metal components of the precursor to explore the enhancement of interface engineering for the ORR. Benefiting from the synergistic effect of the strong interfacial coupling effects of Fe 2 O 3 /Cu and optimized microstructure, FeCu@NC exhibited superior ORR activity and zinc-air battery performance. Experimental and theoretical calculations revealed that the presence of the Fe 2 O 3 /Cu interface breaks the traditional cognition to endow the Cu atoms (intrinsically inferior for the ORR) with a slight positive charge, which serves as the active sites for the ORR. This study provides a novel insight into the design of advanced electrocatalysts for the ORR by interface engineering.