Abstract Developing electrocatalysts with high-Pt-utilization efficiency and appropriate surface oxygen affinity through a facile and scalable route is urgently needed for proton exchange membrane fuel cells. Here, SPD-annealing strategy is demonstrated to prepare ordered low-Pt-loading Pd–Pt–Fe nanoalloys with an average particle size of less than 5 nm and excellent electrocatalytic performance. Furthermore, the ORR performances of Pd–Pt–Fe/C nanoalloy catalysts are rationally modified by means of both precise composition control and structural transformation. With an optimal component proportion, the prepared Pd0.75Pt0.25Fe/C catalyst exhibits the most excellent intrinsic activity due to the synergistic interaction of lattice strain and ligand effect. Benefiting from the compressive strain effect induced by the relatively tight arrangement of the ordered structure, the adsorption energy of the intermediate oxygen-containing species is effectively weakened, enabling the Pd0.75Pt0.25Fe/C to obtain enhanced ORR catalytic performance in acidic condition. Notably, compared with the disordered Pd0.75Pt0.25Fe/C, the ordered Pd0.75Pt0.25Fe/C shows an extremely superior stability of 98.5% mass activity retention after 10 000 cycles. This work could provide a facile and versatile approach to constructing the ordered low-platinum electrocatalysts with enhanced ORR properties.

中文翻译：

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结构有序的低铂负载 Pd-Pt-Fe 纳米合金的合成具有增强的氧还原反应电催化性能

摘要 质子交换膜燃料电池迫切需要通过简便且可扩展的途径开发具有高 Pt 利用率和适当表面氧亲和力的电催化剂。在这里，SPD 退火策略被证明可以制备平均粒径小于 5 nm 且具有优异电催化性能的有序低 Pt 负载 Pd-Pt-Fe 纳米合金。此外，Pd-Pt-Fe/C纳米合金催化剂的ORR性能通过精确的成分控制和结构转变进行了合理的修饰。在最佳组分比例下，由于晶格应变和配体效应的协同相互作用，制备的 Pd0.75Pt0.25Fe/C 催化剂表现出最优异的本征活性。受益于有序结构相对紧密排列引起的压应变效应，有效削弱了中间含氧物种的吸附能，使 Pd0.75Pt0.25Fe/C 在酸性条件下获得增强的 ORR 催化性能。值得注意的是，与无序的 Pd0.75Pt0.25Fe/C 相比，有序的 Pd0.75Pt0.25Fe/C 在 10 000 次循环后表现出极其优异的稳定性，质量活性保持率为 98.5%。这项工作可以提供一种简便且通用的方法来构建具有增强 ORR 性能的有序低铂电催化剂。与无序的 Pd0.75Pt0.25Fe/C 相比，有序的 Pd0.75Pt0.25Fe/C 在 10 000 次循环后显示出极其优异的稳定性，质量活性保持率为 98.5%。这项工作可以提供一种简便且通用的方法来构建具有增强 ORR 性能的有序低铂电催化剂。与无序的 Pd0.75Pt0.25Fe/C 相比，有序的 Pd0.75Pt0.25Fe/C 在 10 000 次循环后显示出极其优异的稳定性，质量活性保持率为 98.5%。这项工作可以提供一种简便且通用的方法来构建具有增强 ORR 性能的有序低铂电催化剂。