Zhang Junchang, Zhao Bo, Liang Wenkai, Zhou Genshu, Liang Zhiqiang, Wang Yawen, Qu Jiangying, Sun Yinghui, Jiang Lin
School of Environment and Civil Engineering Dongguan University of Technology Dongguan Guangdong 523808 China.
School of Chemistry and Chemical Engineering Nantong University Nantong Jiangsu 226019 China.
Adv Sci (Weinh). 2020 Oct 12;7(22):2002630. doi: 10.1002/advs.202002630. eCollection 2020 Nov.
Electrochemical nitrogen reduction reaction (NRR) provides a facile and sustainable strategy to produce ammonia (NH) at ambient conditions. However, the low NH yield and Faradaic efficiency (FE) are still the main challenges due to the competitive hydrogen evolution reaction (HER). Herein, a three-phase electrocatalyst through in situ fabrication of Au nanoparticles (NPs) located on hydrophobic carbon fiber paper (Au/o-CFP) is designed. The hydrophobic CFP surface facilitates efficient three-phase contact points (TPCPs) for N (gas), electrolyte (liquid), and Au NPs (solid). Thus, concentrated N molecules can contact the electrocatalyst surface directly, inhibiting the HER since the lowered proton concentration and overall enhancing NRR. The three-phase Au/o-CFP electrocatalyst presents an excellent NRR performance with high NH yield rate of 40.6 µg h mg at -0.30 V and great FE of 31.3% at -0.10 V versus RHE (0.1 m NaSO). The N-bubble contact angle result and cyclic voltammetry analysis confirm that the hydrophobic interface has a relatively strong interaction with N bubble for enhanced NRR and weak electrocatalytic activity for HER. Significantly, the three-phase Au/o-CFP exhibits excellent stability with a negligible fluctuation of NH yield and FE in seven-cycle test. This work provides a new strategy for improving NRR and simultaneously inhibiting HER.
电化学氮还原反应（NRR）为在环境条件下生产氨（NH₃）提供了一种简便且可持续的策略。然而，由于竞争性析氢反应（HER）的存在，较低的NH₃产率和法拉第效率（FE）仍然是主要挑战。在此，通过原位制备位于疏水碳纤维纸（Au/o-CFP）上的金纳米颗粒（NPs）设计了一种三相电催化剂。疏水的CFP表面促进了N₂（气体）、电解质（液体）和Au NPs（固体）之间高效的三相接触点（TPCPs）。因此，浓缩的N₂分子可以直接接触电催化剂表面，由于质子浓度降低而抑制了HER，并总体上增强了NRR。三相Au/o-CFP电催化剂表现出优异的NRR性能，在相对于可逆氢电极（RHE）为-0.30 V时，NH₃产率高达40.6 μg h⁻¹ mg⁻¹，在相对于RHE为-0.10 V（0.1 m Na₂SO₄）时，法拉第效率高达31.3%。N₂气泡接触角结果和循环伏安分析证实，疏水界面与N₂气泡具有相对较强的相互作用，以增强NRR，而对HER的电催化活性较弱。值得注意的是，三相Au/o-CFP在七次循环测试中表现出优异的稳定性，NH₃产率和FE的波动可忽略不计。这项工作为提高NRR同时抑制HER提供了一种新策略。
