Mixture Phases Engineering of PtFe Nanofoams for Efficient Hydrogen Evolution.

ABSTRACT

Phase engineering is a promising but challenging approach to construct PtFe-based catalysts with efficient hydrogen evolution reaction (HER) performance. Herein, the authors successfully synthesize PtFe nanofoams with face center cubic (fcc) phase, with simple cubic crystalline (scc) phase and with the mixture phases of fcc and scc phases (PtFe-mix) by hydrogen-assisted calcination for the first time. By benchmarking the HER activity, PtFe-mix exhibits excellent activity in 1.0 m KOH, requiring an overpotential of 28 mV to achieve 10 mA cm-2 , which is better than the commercial Pt/C (34 mV). PtFe-mix also possesses remarkable stability up to 24 h. Density functional theory calculations further verify that PtFe-mix shows a more suitable d-band center and lower energy barrier for the initial water dissociation, facilitating the HER process. This work provides a meaningful strategy to design PtFe-based catalysts with efficient activity for hydrogen evolution.