This review underlines the strategies to suppress HER for selective NRR in view of proton-/electron-transfer kinetics, thermodynamics, and electrocatalyst design on the basis of deep understanding for NRR mechanisms.

With the increasingly prominent energy issues and environment problems, the electrocatalytic production of value-added fine chemicals by hybrid water electrolysis has posed much hope for replacing the conventionally energy-intensive chemical...

Integrated/cascade plasma-enabled N2 oxidation and electrocatalytic NO x – (where x = 2, 3) reduction reaction (pNOR-eNO x –RR) holds great promise for the renewable synthesis of ammonia (NH3). However, the corresponding activated effects and process of plasma toward N2 and O2 molecules and the mechanism of eNO x –RR to NH3 are unclear and need to be further uncovered, which largely limits the large-scale deployment of this process integration technology. Herein, we systematically investigate the plasma-enabled activation and recombination processes of N2 and O2 molecules, and more meaningfully, the mechanism of eNO x –RR at a microscopic level is also decoupled using copper (Cu) nanoparticles as a representative electrocatalyst. The concentration of produced NO x in the pNOR system is confirmed as a function of the length for spark discharge as well as the volumetric ratio for N2 and O2 feeding gas. The successive protonation process of NO x – and the key N-containing intermediates (e.g., −NH2) of eNO x –RR are detected with in situ infrared spectroscopy. Besides, in situ Raman spectroscopy further reveals the dynamic reconstruction process of Cu nanoparticles during the eNO x –RR process. The Cu nanoparticle-driven pNOR-eNO x –RR system can finally achieve a high NH3 yield rate of ∼40 nmol s–1 cm–2 and Faradaic efficiency of nearly 90%, overperforming the benchmarks reported in the literature. It is anticipated that this work will stimulate the practical development of the pNOR-eNO x –RR system for the green electrosynthesis of NH3 directly from air and water under ambient conditions.