Platinum (Pt) supported on high surface area carbon has been the most widely used electrocatalyst in proton exchange membrane fuel cell (PEMFC). However, conventional carbon supports are susceptible to corrosion at high potentials, leading to severe degradation of electrochemical performance. In this work, titanium carbonitride embedded in mesoporous carbon nanofibers (m-TiCN NFs) are reported as a promising alternative to address this issue. Benefiting from the interpenetrating conductive pathways inside the one-dimensional (1D) nanostructures and the embedded TiCN nanoparticles (NPs), m-TiCN NFs exhibit excellent stability at high potentials and interact strongly with Pt NPs. Subsequently, m-TiCN NFs-supported Pt NPs deliver remarkably enhanced oxygen reduction reaction (ORR) activity and durability, with negligible activity decay and less than 5% loss of electrochemical surface area（ECSA） after 50 000 cycles. Moreover, the fuel cell assembled by this catalyst delivers a maximum power density of 1.22 W cm⁻² and merely 3% loss after 30 000 cycles of accelerated durability tests under U.S. Department of Energy (DOE) protocols. The improved ORR activity and durability are attributed to the superior corrosion resistance of the m-TiCN NF support and the strong interaction between Pt and m-TiCN NFs.

中文翻译：

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嵌入介孔碳纳米纤维中的碳氮化钛与 Pt 之间的强相互作用可实现持久的氧还原

高表面积碳负载的铂 (Pt) 是质子交换膜燃料电池 (PEMFC) 中使用最广泛的电催化剂。然而，传统的碳载体在高电位下容易腐蚀，导致电化学性能严重退化。在这项工作中，嵌入介孔碳纳米纤维（m-TiCN NF）的碳氮化钛被报道为解决这一问题的有前途的替代品。受益于一维 (1D) 纳米结构内部的互穿导电通路和嵌入的 TiCN 纳米颗粒 (NP)，m-TiCN NF 在高电位下表现出优异的稳定性，并与 Pt NP 发生强烈相互作用。随后，m-TiCN NFs负载的Pt NPs显着增强了氧还原反应（ORR）活性和耐久性，50000次循环后活性衰减可以忽略不计，电化学表面积（ECSA）损失低于5%。此外，由该催化剂组装的燃料电池可提供1.22 W cm ^-2的最大功率密度，并且根据美国能源部（DOE）协议进行30 000次加速耐久性测试后，功率损失仅为3%。 ORR 活性和耐久性的提高归因于 m-TiCN NF 载体优异的耐腐蚀性以及 Pt 和 m-TiCN NF 之间的强相互作用。