Cu_(3)N自支撑电极制备及其电催化氮气还原性能研究

Fabrication of self-supported Cu_(3)N electrode for electrocatalytic nitrogen reduction reaction

利用可再生能源衍生电力电催化氮气(N_(2))还原制氨(NH_(3))为实现绿色可持续发展提供了新思路,但该过程需要高效率、高选择性和高稳定性的廉价电催化剂。过渡金属氮化物(TMNs)由于其独特的电子结构和催化机理近年来被广泛研究应用于电催化氮气还原反应(NRR),但是目前关于氮化铜材料的电催化NRR研究报道较少。本研究采用简单一步氮化法将泡沫铜(CF)高温氮化制备了三维自支撑型氮化铜电极(Cu_(3)N/CF),通过各种表征手段对该电极进行了系统的结构分析和形貌表征,并研究了其在中性条件下的电催化NRR性能和稳定性。结果表明,在0.1 mol/L Na_(2)SO_(4)溶液中,Cu_(3)N/CF电极在-0.2 V的电位下具有最佳的电催化NRR性能,其NH_(3)速率为1.12×10^(10)mol/(s·cm^(2)),法拉第效率为1.5%,并且表现出优异的电催化循环稳定性和结构稳定性。

Electrocatalytic reduction of nitrogen(N_(2)) to ammonia(NH_(3)) by renewable energy-derived electricity provides a new route for sustainable development. But this process requires high-efficiency, high-selectivity and high-stability, inexpensive electrocatalysts. Owing to the unique electronic structure and catalytic mechanism,transition metal nitrides(TMNs) have been widely investigated as electrocatalysts for nitrogen reduction reaction(NRR) in recent years. However, to date, copper nitride-based materials are rarely reported for NRR. In this study, a three-dimensional self-supported copper nitride electrode(Cu_(3)N/CF) was prepared by a simple one-step hightemperature nitridation of copper foam(CF). The structure and morphology of Cu_(3)N/CF were systematically characterized and its NRR catalytic performance and stability were evaluated in neutral media. The results show that Cu_(3)N/CF electrode achieves high ammonia generation rate(1.12 × 10^(10)mol/(s·cm^(2)) and faradaic efficiency(1.5%)at-0.2 V vs RHE in 0.1 mol/L Na_(2)SO_(4). In addition, it also exhibits excellent electrocatalytic cycle stability and structural stability.