Gas Dynamically Confined Synthesis of Platinum-Based Intermetallic Nanowires for Active and Ultrastable Oxygen Reduction Catalysis
Xing Hu, Kezhu Jiang, Fucheng Wang, Shize Geng, Yibo Liu, Shuang Meng, Huhu Su, Shan Zhu, Lingzheng Bu, Cong Chen, Shijian Zheng
Abstract
Precisely controlling the surface and internal atomic structures of platinum (Pt)-based nanocrystals remains a critical challenge for developing high-performance oxygen reduction reaction (ORR) catalysts. Here, we report a gas dynamically confined strategy leveraging hydrogen adsorption to synthesize Pt-based intermetallic nanowires (NWs) with ordered bulk atomic lattices (Pt 3 Fe L1 2, Pt 3 Co L1 2, PtNi L1 0 ) and abundant high-index {311}, {211}, and {221} facets. Dynamic hydrogen adsorption reduces surface energy and suppresses atomic migration during high-temperature annealing, preserving the one-dimensional morphology and enabling structural ordering, as confirmed by in situ transmission electron microscopy and density functional theory calculations. The resultant ordered Pt 3 Fe NWs exhibit a mass activity of 0.98 A mg Pt –1 and ultrahigh stability, retaining 93.9% of mass activity after 30,000 cycles and 86.4% of power density after 70,000 cycles. The synergistic effects of ordered atomic arrangements, high-index facets, and one-dimensional geometry optimize electronic properties and active-site energetics, enhancing both activity and stability. This strategy of designing structurally precise Pt-based intermetallic catalysts demonstrates a potential for application in fuel cell technologies.