As the anode reaction of anion exchange membrane fuel cells (AEMFCs), hydrogen oxidation reaction (HOR) has attracted great attention, however, suffers from the low kinetics in alkaline condition. In this work, we demonstrate that the strong synergy at the heterointerface of hexagonal close-packed (hcp) and face-centered cubic (fcc) phase of Ru-Sn nanoflowers can greatly contribute to accelerate the alkaline HOR kinetics and strengthen the resistance to CO, a common poison present in industrially produced H2. Experimental observations, in-situ characterizations, and theoretical calculations suggest that the interfacial synergy, linked to the ratio of fcc/hcp phase, can modulate the adsorption ability of H, weaken the binding strength to CO, and reduce the energy barrier for CO oxidation. Impressively, the optimal fcc0.42 Ru-Sn/C exhibits a mass activity and specific activity of 4.9 A mgRu−1 and 6.7 mA cmECSA−2 at 50 mV, respectively, which is 9.8 time and 7.4 time higher than those of hcp Ru/C, surpassing commercial Pt/C and other recently reported catalysts for HOR. Moreover, the fuel cell assembled with fcc0.42 Ru-Sn/C exhibits a power peak density (PPD) of 12.46 W mgRu−1.

中文翻译：

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用于增强碱性氢氧化反应的 Ru-Sn 纳米催化剂的相和界面工程


作为阴离子交换膜燃料电池（AEMFC）的阳极反应，氢氧化反应（HOR）引起了人们的广泛关注，但其在碱性条件下动力学较低。在这项工作中，我们证明了Ru-Sn纳米花的六方密堆积（hcp）和面心立方（fcc）相异质界面处的强协同作用可以极大地促进碱性HOR动力学并增强对CO的抵抗力，工业生产的氢气中存在的一种常见毒物。实验观察、原位表征和理论计算表明，与 fcc/hcp 相比例相关的界面协同作用可以调节 H 的吸附能力，削弱与 CO 的结合强度，并降低 CO 氧化的能垒。令人印象深刻的是，最佳 fcc0.42 Ru-Sn/C 在 50 mV 下的质量活性和比活性分别为 4.9 A mgRu−1 和 6.7 mA cmECSA−2，分别是 hcp Ru 的 9.8 倍和 7.4 倍/C，超越了商业 Pt/C 和其他最近报道的 HOR 催化剂。此外，用fcc0.42 Ru-Sn/C组装的燃料电池的功率峰值密度（PPD）为12.46 W mgRu−1。