Efficient Electrochemical Nitrate Reduction to Ammonia with Copper‐Supported Rhodium Cluster and Single‐Atom Catalysts

Abstract

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.

Single‐Atom Bi Alloyed Pd Metallene for Nitrate Electroreduction to Ammonia

“…+ at ≈1460 cm −1 ). [63][64][65] For Bi 1 Pd (Figure 5d), with increasing potentials, all deoxidation intermediates (*NO, *NO 2 ), protonation intermediates (*NH, *NH 2 ) and NH 4 + can be observed and their band intensity is gradually increased, suggesting the effective NO 3 − activation, deoxidation, and protonation on Bi 1 Pd to continuously produce NH 3 . As a sharp contrast, Pd metallene (Figure 5e) shows distinct vibration bands of deoxidation intermediates (*NO, *NO 2 ), but too weak bands of protonation intermediates (*NH, *NH 2 ), consequently resulting in a poor NH 3 yield, as reflected by the much lower band intensity of NH 4…”

Rare-earth La-doped VS2−xfor electrochemical nitrate reduction to ammonia

“…[4][5][6] However, NO 3 RR effectiveness is still retarded by the complex multi-electron transfer process and easy occurrence of side reactions especially competing for the hydrogen evolution reaction (HER). [7][8][9] Therefore, it is urgently required to explore effective NO 3 RR electrocatalysts for active and selective NO 3 − -to-NH 3 conversion. [10][11][12][13][14] To date, substantial efforts have been devoted to exploring many potential NO 3 RR catalysts.…”

Swinging Hydrogen Evolution to Nitrate Reduction Activity in Molybdenum Carbide by Ruthenium Doping

“…The reaction kinetics of NO 3 RR is therefore strongly correlated to the nature of hydrogen transfer and the density of available hydrogen donors . An in-depth understanding of elementary steps in NO 3 RR is needed for rational catalyst designs, for instance, an ideal NO 3 RR catalyst should preferably coactivate *H and *NO 3 on the surface, while avoiding fast recombination of *H into H 2 or poisoning by intermediates at high nitrate concentrations. − …”