Ordered PtFeIr Intermetallic Nanowires Prepared through a Silica‐Protection Strategy for the Oxygen Reduction Reaction

Developing efficient and stable Pt‐based oxygen reduction reaction (ORR) catalysts is a way to promote the large‐scale application of fuel cells. Pt‐based alloy nanowires are promising ORR catalysts, but their application is hampered by activity loss caused by structural destruction during long‐term cycling. Herein, the preparation of ordered PtFeIr intermetallic nanowire catalysts with an average diameter of 2.6 nm and face‐centered tetragonal structure (fct‐PtFeIr/C) is reported. A silica‐protected strategy prevents the deformation of PtFeIr nanowires during the phase transition at high temperature. The as‐prepared fct‐PtFeIr/C exhibited superior mass activity for ORR (2.03 A mgPt−1) than disordered PtFeIr nanowires with face‐centered cubic structure (1.11 A mgPt−1) and commercial Pt/C (0.21 A mgPt−1). Importantly, the structure and electrochemical performance of fct‐PtFeIr/C were maintained after stability tests, showing the advantages of the ordered structure. Ordered PtFeIr intermetallic nanowires supported on commercial carbon were synthesized. Coating with SiO2 and the addition of Ir enabled the integrity of the nanowire structure to be maintained during their transformation from a disordered fcc‐phase to an ordered fct‐phase. The fct‐phase nanowires exhibited much better ORR activity and structural and electrochemical stability than the fcc‐phase ones.