The electrochemical nitrate reduction reaction (NITRR) provides a promising solution for restoring the imbalance in the global nitrogen cycle while enabling a sustainable and decentralized route to source ammonia. Here, we demonstrate a novel electrocatalyst for NITRR consisting of Rh clusters and single‐atoms dispersed onto Cu nanowires (NWs), which delivers a partial current density of 162 mA cm−2 for NH3 production and a Faradaic efficiency (FE) of 93 % at −0.2 V vs. RHE. The highest ammonia yield rate reached a record value of 1.27 mmol h−1 cm−2. Detailed investigations by electron paramagnetic resonance, in situ infrared spectroscopy, differential electrochemical mass spectrometry and density functional theory modeling suggest that the high activity originates from the synergistic catalytic cooperation between Rh and Cu sites, whereby adsorbed hydrogen on Rh site transfers to vicinal *NO intermediate species adsorbed on Cu promoting the hydrogenation and ammonia formation.

Ammonia is an essential bulk chemical and the main component of fertilizers. In addition, the use of ammonia (NH3) as an energy carrier and hydrogen storage material has continuously surged. Electrochemical nitrate reduction is a low-carbon, environment-friendly, and efficient method of ammonia synthesis, which has attracted extensive attention in recent years; however, the overpotential needed to produce NH3 with most catalysts is still too large. In this work, we rationally designed rhodium nanoflowers (Rh NFs) composed of ultrathin nanosheets and explored their performance for the electrocatalytic nitrate reduction to ammonia (NITRR). With a high faradic efficiency of 95% at 0.2 V vs reversible hydrogen electrode (RHE) for ammonia production, the overpotential required for the NH3 formation on an Rh NF catalyst is much lower than on most previously reported catalysts. X-ray absorption spectroscopy (XAS) analysis shows that there are low-coordination atoms in the Rh NF catalyst, which can promote the adsorption of NO3 – ions and stabilize intermediates as revealed by the density functional theory (DFT) calculation, resulting in efficient NITRR performance.

Decoupling and understanding the various mass, charge, and heat transport phenomena involved in the electrocatalytic transformation of small molecules (i.e., CO 2 , CO, H 2 , N 2 , NH 3 , O 2 , and CH 4 ) is challenging but it can be readily achieved using dimensionless quantities (i.e., Reynolds, Sherwood, Schmidt, Damköhler, Nusselt, Prandtl, and Peclet Numbers) to simplify the characterization of systems with multiple interacting physical phenomena.Herein we report the development of a gastight rotating cylinder electrode cell with welldefined mass transport characteristics that can be applied to experimentally decouple mass transfer effects from intrinsic kinetics in electrocatalytic systems. The gastight rotating cylinder electrode cell enables the dimensionless analysis of electrocatalytic systems and should enable the rigorous research and development of electrocatalytic technologies.

Copper-based catalysts are established catalytic systems for the electrocatalytic CO2 reduction reaction (CO2RR), where wasteful CO2 is converted into valuable industrial resources, such as energy-dense C2+ products, using energy from...

The electrochemical nitrate reduction reaction (NITRR) provides a promising solution for restoring the imbalance in the global nitrogen cycle while enabling a sustainable and decentralized route to source ammonia. Here, we demonstrate a novel electrocatalyst for NITRR consisting of Rh clusters and single-atoms dispersed onto Cu nanowires (NWs), which delivers a partial current density of 162 mA cm À 2 for NH 3 production and a Faradaic efficiency (FE) of 93 % at À 0.2 V vs. RHE. The highest ammonia yield rate reached a record value of 1.27 mmol h À 1 cm À 2 . Detailed investigations by electron paramagnetic resonance, in situ infrared spectroscopy, differential electrochemical mass spectrometry and density functional theory modeling suggest that the high activity originates from the synergistic catalytic cooperation between Rh and Cu sites, whereby adsorbed hydrogen on Rh site transfers to vicinal *NO intermediate species adsorbed on Cu promoting the hydrogenation and ammonia formation.