Understanding the correlation between exposed surfaces and performances of controlled nanocatalysts is one of the most effective strategy to enhancing electrocatalysis, but it has unexplored for nitrogen reduction reaction (NRR) yet. Here, we firstly report a controlled synthesis of well-defined Pt₃Fe nanocrystals with tunable morphologies (nanocube, nanorod and nanowire) as ideal model electrocatalysts for investigating NRR on different exposed facets. The detailed electrocatalytic studies reveal that the Pt₃Fe nanocrystals exhibit shape-dependent NRR electrocatalysis. The optimized Pt₃Fe nanowires bounded with high-index facets exhibit excellent selectivity (no N₂H₄ is detected), high activity with NH₃ yield of 18.3 μg h⁻¹ mg⁻¹_cat (0.52 μg h⁻¹ cm⁻²_ECSA) and Faraday efficiency of 7.3% at -0.05 V versus reversible hydrogen electrode, outperforming the {200} facet-enclosed Pt₃Fe nanocubes and {111} facet-enclosed Pt₃Fe nanorods. It also shows well stability with negligible activity change after five cycles. DFT calculation reveals that, with high-indexed facet engineering, the Fe-3d band plays as an efficient d-d coupling correlation center for boosting the Pt 5d-electronic exchange and transfer activities towards NRR.

中文翻译：

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纳米立方体、纳米棒和纳米线的不同 Pt3Fe 纳米结构上的暴露面控制 N2 电还原

了解暴露表面与受控纳米催化剂性能之间的相关性是增强电催化的最有效策略之一，但尚未探索氮还原反应 (NRR)。在这里，我们首先报告了具有可调形态（纳米立方体、纳米棒和纳米线）的明确定义的 Pt ₃ Fe 纳米晶体的受控合成，作为研究不同暴露面的 NRR 的理想模型电催化剂。详细的电催化研究表明 Pt ₃ Fe 纳米晶体表现出形状依赖的 NRR 电催化。优化的 Pt ₃ Fe 纳米线与高指数小平面结合表现出出色的选择性（未检测到N ₂ H ₄），对 NH 具有高活性₃产量为 18.3 μg h ^-1 mg ^-1 _cat (0.52 μg h ^-1 cm ^-2 _ECSA ) 和在 -0.05 V 下与可逆氢电极相比法拉第效率为 7.3%，优于 {200} 面封闭的 Pt ₃ Fe 纳米立方体和{111}面封闭的Pt ₃ Fe纳米棒。它还显示出良好的稳定性，五个循环后活性变化可忽略不计。DFT 计算表明，通过高指数刻面工程，Fe-3d 带作为有效的dd耦合相关中心，用于促进 Pt 5d 电子交换和向 NRR 的转移活动。