The Role of Oxidation of Silver in Bimetallic Gold–Silver Nanocages on Electrocatalytic Activity of Nitrogen Reduction Reaction
The Role of Oxidation of Silver in Bimetallic Gold–Silver Nanocages on Electrocatalytic Activity of Nitrogen Reduction Reaction
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双金属金银纳米笼中银的氧化对氮还原反应电催化活性的影响
DOI：
10.1021/acs.jpcc.9b01107
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
El-Sayed, Mostafa A.
中科院分区：
文献类型：
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作者：
Nazemi, Mohammadreza;El-Sayed, Mostafa A.
从氮气和水的电化学氨合成提供了一种替代路线，以清洁，可持续和分散的方式，如果电力是由可再生能源产生的热化学过程（哈伯-博世）。我们先前展示了使用中空的Au-Ag纳米笼作为有效的电催化剂用于在水溶液中电合成氨。当考虑电化学氮还原反应（NRR）用于工业应用的可行性时，电催化剂在电化学氮还原反应（NRR）期间的稳定性是至关重要的。在这里，银的氧化在不同的局域表面等离子体共振峰的位置上的NRR的电催化活性的Ag2O-Au纳米笼中的作用进行了研究，通过氧气处理的Ag通过简单的氧化过程形成Ag2O-Au纳米笼。电催化NRR活性与NH3的产率为2.14 μ g cm-2h-1和法拉第效率为23.4%，在-0.4 V对可逆氢电极（RHE）使用Ag2O-Au-719。这种电化学性能大大降低了我们之前报道的使用Ag-Au-715纳米笼的NRR活性（3.74 μ g cm-2h-1和35.9%，-0.4 V vs RHE）。这项工作突出了在电化学NRR中无O2环境对于稳定的N2电解操作的重要性，并辨别了Ag对Au-Ag纳米笼对NRR的选择性和活性的作用。
Electrochemical ammonia synthesis from nitrogen and water provides an alternative route to the thermochemical process (Haber-Bosch) in a clean, sustainable, and decentralized way if electricity is generated from renewable sources. We previously demonstrated the use of bimetallic hollow Au–Ag nanocages as an effective electrocatalyst for electrosynthesis of ammonia in an aqueous solution. The stability of the electrocatalyst during electrochemical nitrogen reduction reaction (NRR) is of paramount importance when considering the feasibility of electrochemical NRR for industrial applications. Here, the role of oxidation of silver in bimetallic Au–Ag nanocages with various localized surface plasmon resonance peak positions on electrocatalytic activity of NRR is studied by oxygen treatment of Ag through the simple oxidation process to form Ag2O–Au nanocages. Electrocatalytic NRR activity with an NH3yield rate of 2.14 μg cm–2h–1and Faradaic efficiency of 23.4% was achieved at −0.4 V versus reversible hydrogen electrode (RHE) using Ag2O–Au-719. This electrochemical performance is a substantial reduction to our previously reported NRR activity using Ag–Au-715 nanocages (3.74 μg cm–2h–1and 35.9% at −0.4 V vs RHE). This work highlights the importance of an O2-free environment in electrochemical NRR for the stable N2electrolysis operation and discerns the role of Ag on the selectivity and activity of bimetallic Au–Ag nanocages toward NRR.