Precisely controlling the strain of Pt-based intermetallic to ensure high performance and stability is a massive task for sustainable proton-exchange-membrane-fuel-cells. Herein, the Al single-atom was trapped into the L12-Pt3Co intermetallic core to precisely tailor the strain state on the Pt-skin for fast oxygen reduction reaction kinetics. Theoretical calculations firstly predicted that only tailored tension can accelerate the protonation of O2 on L12-Pt3Co@Pt without creating an additional energy barrier for subsequent oxygen-containing intermediates desorption. Experimentally, Al single-atom confined in the L12-Pt3Co lattice by substituting partial Co occupancy, imposing tailored ∼ 0.2 % tension on Pt-skin compared to the L12-Pt3Co. L12-Al-Pt3Co@Pt/C exhibits enhanced mass activity which is ten-time improvement over commercial Pt/C. More significantly, XAS and DFT results reveal that the Al single-atom can strengthen the Pt-Co bonding, enhancing the stability of L12-Al-Pt3Co@Pt/C in oxygen reduction. This work provides an avenue to design the strain by single-atom for sustainable energy conversion technologies.

中文翻译：

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单原子 Al 精确调节 Pt3Co 金属间化合物的应变，实现卓越的氧催化性能


精确控制铂基金属间化合物的应变以确保高性能和稳定性是可持续质子交换膜燃料电池的一项艰巨任务。在此，Al 单原子被捕获到 L12-Pt3Co 金属间化合物核心中，以精确调整 Pt 皮上的应变状态，从而实现快速氧还原反应动力学。理论计算首先预测，只有定制的张力才能加速L12-Pt3Co@Pt上O2的质子化，而不为随后的含氧中间体解吸产生额外的能量势垒。实验上，Al 单原子通过取代部分 Co 占据而被限制在 L12-Pt3Co 晶格中，与 L12-Pt3Co 相比，在 Pt 表皮上施加了约 0.2% 的张力。 L12-Al-Pt3Co@Pt/C 表现出增强的质量活性，比商业 Pt/C 提高了十倍。更重要的是，XAS和DFT结果表明，Al单原子可以增强Pt-Co键合，增强L12-Al-Pt3Co@Pt/C在氧还原中的稳定性。这项工作为可持续能源转换技术的单原子设计应变提供了途径。