The electrocatalytic nitrogen (N₂) reduction reaction is recognized as a green and sustainable approach for ammonia (NH₃) synthesis alternative to the traditional industrial method – the Haber–Bosch process, while an efficient electrocatalysis of such a process is a prerequisite for N₂ reduction. Developing a cost-effective electrocatalyst for the electrocatalytic nitrogen reduction reaction (NRR) under ambient conditions with an excellent catalytic performance remains a great challenge. Here, we report a facile hydrothermal reaction to synthesize Fe-doped manganese oxide (MnO₂) with a nanoneedle morphology as a cost-effective electrocatalyst for the NRR. It is verified that Fe plays a critical role in the NRR. This catalyst shows an excellent catalytic performance with a high faradaic efficiency of 16.8% and a high NH₃ formation rate of 39.2 μg h⁻¹ mg_cat.⁻¹ at −0.29 V vs. the reversible hydrogen electrode in 0.1 M Na₂SO₄, which are much higher than those of all reported Mn-based NRR catalysts and many other previously reported catalysts. This catalyst also shows excellent durability during electrolysis and recycling tests. In addition, the electrocatalyst mechanism is also assessed in combination with density functional theory.

中文翻译：

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通过MnO2表面上的Fe增强氮活化来促进电催化氮还原为氨

电催化氮（N ₂）还原反应是公认的绿色和可持续的氨（NH ₃）合成方法，可替代传统的工业方法–哈伯-博世（Haber-Bosch）工艺，而这种工艺的有效电催化是制氮的先决条件₂减少。在环境条件下开发具有优异催化性能的具有成本效益的电催化氮还原反应（NRR）的电催化剂仍然是一个巨大的挑战。在这里，我们报道了一种容易进行的水热反应，以合成掺铁的锰氧化物（MnO ₂），具有纳米针形态，可作为具有成本效益的NRR电催化剂。事实证明，铁在NRR中起关键作用。该催化剂显示出优异的催化性能，具有高达16.8％的法拉第效率和39.2μgh ^-1 mg _cat的高NH ₃生成速率_。在-0.29 V时的^-1与在0.1 M Na ₂ SO _4中的可逆氢电极相比，远高于所有报道的Mn基NRR催化剂和许多其他先前报道的催化剂。该催化剂在电解和循环测试中也显示出优异的耐久性。此外，还结合密度泛函理论对电催化剂机理进行了评估。