Ammonia (NH₃) is widely used for human life and considered a green energy carrier without CO₂ emissions; thus, green and sustainable NH₃ synthesis is of great importance. The traditional Haber-Bosch process requires harsh conditions with serious environmental implications. Therefore, numerous research is focused on the efficient synthesis of NH₃ from abundant N₂/air and water under ambient conditions, utilizing renewable energy sources. Despite the fact that the electrocatalytic N₂ reduction reaction (eNRR) is an ideal method for NH₃ synthesis, the NH₃ yield and Faradaic efficiency (FE) are severally hampered by the inertness of N₂, impeding its industrial application. Various strategies have been proposed to synthesize highly efficient heterogeneous catalysts for N₂ adsorption and dissociation to improve NH₃ yield and FE. Besides, benefiting from the nonthermal plasma N₂ oxidation reaction (pNOR) and electrocatalytic nitrate/nitrite reduction reaction (eNO_xRR), the two-step approach overcomes the limitations of eNRR, attracting significant interest. This strategy facilitates N₂ splitting, which is a crucial step in the synthesis of NH₃. Additionally, eNO_xRR involves complex intermediates, making it essential to investigate catalysts with high selectivity of NH₃. Overall, through the optimization of catalysts and reaction systems, NH₃ can be synthesized with high efficiency. The two-step strategy is the most realistic process for mass NH₃ production, but several challenges still need to be addressed, including improving the overall energy efficiency and scaling up the technology for industrial applications.

中文翻译：

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可持续氨生产的反应体系构建和催化剂活性位点的调节


氨 （NH₃） 广泛用于人类生活，被认为是一种不排放 CO₂ 的绿色能源载体;因此，绿色和可持续的 NH₃ 合成非常重要。传统的 Haber-Bosch 工艺需要恶劣的条件，对环境有严重影响。因此，许多研究都集中在利用可再生能源在环境条件下从丰富的 N₂/空气和水中高效合成 NH₃。尽管电催化 N₂ 还原反应 （eNRR） 是合成 NH₃ 的理想方法，但 NH₃ 产率和法拉第效率 （FE） 受到 N₂ 惰性的严重影响，阻碍了其工业应用。已经提出了各种策略来合成用于 N₂ 吸附和解离的高效非均相催化剂，以提高 NH₃ 产率和 FE。此外，得益于非热等离子体 N₂ 氧化反应 （pNOR） 和电催化硝酸盐/亚硝酸盐还原反应 （eNO_xRR），两步法克服了 eNRR 的局限性，引起了极大的兴趣。这种策略促进了 N₂ 的分裂，这是 NH₃ 合成的关键步骤。此外，eNO_xRR 涉及复杂的中间体，因此必须研究对 NH₃ 具有高选择性的催化剂。总体而言，通过催化剂和反应体系的优化，可以高效合成 NH₃。 两步策略是大规模 NH₃ 生产最现实的过程，但仍需要解决一些挑战，包括提高整体能源效率和扩大工业应用技术。