Due to its high energy density, carbon-free character, and the convenience for storage and transportation, ammonia (NH₃) is considered as an energy vector, capable of being used for energy storage and directly as a fuel. Increasing demands for ammonia have necessitated the development of alternative synthesis approaches as the backup technology to the energy-intensive Haber-Bosch process. Among others, the electrosynthesis of ammonia (ESA) technology offers a promising approach to produce NH₃ via a cathodic nitrogen reduction reaction (NRR). However, current ESA technologies desperately suffer from insufficient production rates (<10^-6 mol h^-1 cm^-1) and low Faradaic efficiency (<30%) due to the lack of highly active and selective NRR catalysts and favorable electrolytes to suppress competitive hydrogen evolution reaction. This review provides an insight into the ESA technology with an emphasis on the design of catalysts/electrolytes system that optimizes the production of NH₃ from N₂ and H₂O under ambient conditions. The principle and reaction mechanisms of the NRR are briefly analyzed in the first section, followed by the impacts of electrochemical components (e.g., catalysts and electrolytes) that define the effectiveness of EAS technologies. The challenges that limited the developments and the approaches that researchers have focused on the catalyst developments are discussed in detail with the main emphasis on the combined catalyst/electrolyte systems. Finally, NRR performance evaluation methods, along with economic analysis of the EAS, are critically examined.

由于氨（NH ₃）具有高的能量密度，无碳的特性以及存储和运输的便利性，因此被认为是一种能量载体，可以用于能量存储并直接用作燃料。对氨的需求不断增加，因此有必要开发替代合成方法，作为高能耗哈伯-博世（Haber-Bosch）工艺的备用技术。其中，氨的电合成（ESA）技术提供了一种通过阴极氮还原反应（NRR）生产NH ₃的有前途的方法。但是，当前的ESA技术极度遭受生产率不足（<10 ^-6 mol h ^-1 cm ^-1）和法拉第效率低（<30％）是由于缺乏抑制活性氢释放反应的高活性和选择性NRR催化剂以及有利的电解质。这篇综述提供了对ESA技术的深入了解，重点是优化环境条件下由N ₂和H ₂ O产生NH ₃的催化剂/电解质系统的设计。在第一部分中简要分析了NRR的原理和反应机理，然后介绍了电化学成分的影响（例如（催化剂和电解质）来定义EAS技术的有效性。详细讨论了限制开发的挑战以及研究人员专注于催化剂开发的方法，重点是催化剂/电解质组合体系。最后，对NRR绩效评估方法以及EAS的经济分析进行了严格审查。