Barrier-free Interface Electron Transfer on PtFe-Fe₂C Janus-like Nanoparticles Boosts Oxygen Catalysis

Designing highly efficient interface catalysts with new interface-enhancing mechanisms for the oxygen reduction reaction (ORR) in acid solution still remains a significant challenge. Here, we report a class of stable PtFe-Fe2C Janus-like nanoparticle (NP) interface catalysts with an unrevealed barrier-free interface electron-transfer property that greatly boosts ORR catalytic activity and stability. The PtFe-Fe2C Janus-like NPs showed much higher catalytic activity for ORR than either PtFe or Fe2C NPs in both acidic and alkaline electrolytes. Density functional theory simulations revealed that a barrier-free interface electron transfer on the interface of PtFe-Fe2C Janus-like NPs is the main factor in enhancing ORR activity. This interface electron-transfer property makes them the most active for ORR among all reported PtFe-based nanocatalysts. We further demonstrate that this barrier-free interface electron-transfer property can be readily generalized to other systems, such as the hydrogen evolution reaction and H2O2reduction electrocatalysis, to achieve better electrocatalytic enhancement. Proton-exchange membrane fuel cells (PEMFCs) are considered to be of great importance as a renewable energy system for automobile and portable electronic devices because of their high energy conversion efficiency, low operation temperature, and low pollution emission. However, the slow kinetics of the oxygen reduction reaction (ORR) is a major barrier for the commercialization of PEMFCs. Here, we report a class of stable PtFe-Fe2C Janus-like nanoparticle interface catalysts with an unrevealed barrier-free interface electron-transfer property for greatly boosting ORR catalytic activity and stability. We further demonstrate that this barrier-free interface electron-transfer property can be readily generalized to other electrocatalytic systems with enhanced catalytic properties. This work opens up great opportunities for both technological applications in renewable energies and fundamental mechanism studies in electrocatalysis. PtFe-Fe2C Janus-like nanoparticle (NP) interface catalysts with an unrevealed barrier-free interface electron-transfer property show highly efficient ORR catalytic activity and stability in both acidic and alkaline electrolytes.