Abstract

As a promising fuel candidate, ammonia has been successfully used as anode feed in alkaline fuel cells. However, current technology in catalysts for ammonia electro-oxidation reaction (AOR) with respect to both cost and performance is inadequate to ensure large scale commercial application of direct ammonia fuel cells. Recent studies found that alloying Pt with different transition metals and controlling the morphology of catalysts can improve the AOR activity, and thus potentially can solve the cost issue. Herein, (100)-terminated Pt-M nanocubes (M = 3d-transition metals Fe, Co, Ni, Zn) are synthesized via wet-chemistry method and their catalytic activities toward AOR are evaluated. The addition of Fe, Co, Ni and Zn elements can enhance the AOR activity due to decrease in oxophilicity of platinum and bifunctional mechanism. Pt-Zn exhibits the maximum mass activity and specific activity with values of 0.41 A/mg_Pt and 1.69 mA/cm² that are 1.6 and 1.8 times higher than Pt nanocubes, respectively. Pt-Fe, Pt-Co and Pt-Ni nanocubes also illustrate higher mass and specific activities compared to Pt nanocubes.

中文翻译：

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立方铂合金氨氧化反应的研究

摘要

作为有前途的燃料候选者，氨已成功地用作碱性燃料电池的阳极进料。然而，就成本和性能而言，用于氨电氧化反应（AOR）的催化剂中的当前技术不足以确保直接氨燃料电池的大规模商业应用。最近的研究发现，将Pt与不同的过渡金属合金化并控制催化剂的形态可以提高AOR活性，从而有可能解决成本问题。在这里，通过湿化学方法合成了（100）端接的Pt-M纳米立方体（M = 3d过渡金属Fe，Co，Ni，Zn），并评估了它们对AOR的催化活性。Fe，Co，Ni和Zn元素的添加由于铂的亲氧性降低和双功能机理而可以增强AOR活性。_Pt和1.69 mA / cm ²分别是Pt纳米立方体的1.6倍和1.8倍。与Pt纳米立方体相比，Pt-Fe，Pt-Co和Pt-Ni纳米立方体也显示出更高的质量和比活度。