NH3 Yield Rate Research Articles

Achieving a Thermodynamic Self‐Regulation Dynamic Adsorption Mechanism for Ammonia Synthesis through Selective Orbital Coupling

With the continuous pursuing on the improvement of catalytic activity, a catalyst performed exceeding catalytic volcano plots is desired, while it is impeded by the adsorption‐energy scaling relations of reaction intermediates. Numerous efforts have been focused on optimizing the initial and final intermediates to circumvent the scaling relations for an improved performance. For a step forward, simultaneously optimizing all intermediates is essential to explore the theoretical maximum of catalytic activity. Herein, we proposed a dynamic adsorption mechanism (DAM) to independently regulate the adsorption configurations of all intermediates of electrochemical nitrogen reduction reaction (NRR). To demonstrate the DAM, a multi‐site NbNi3 intermetallic is developed, which enables suitable adsorption energies of different intermediates via modulating orbital coupling mechanisms. As a result, NbNi3 achieves an ultra‐low limiting potential of NRR of −0.11 V vs. reversible hydrogen electrode (RHE). Strikingly, the theoretical result is confirmed by a proof‐of‐concept experiment, wherein the nanoporous NbNi3 electrode exhibits a remarkable NH3 yield rate of 25.89 μg h−1 cm−2 with the Faradic efficiency of 33.15% at −0.25 V vs. RHE. Overall, this work brings out a new strategy to avoid the scaling relations, and opens up a promising avenue toward high‐efficiency NRR catalysts.

Achieving a Thermodynamic Self-Regulation Dynamic Adsorption Mechanism for Ammonia Synthesis through Selective Orbital Coupling.

With the continuous pursuing on the improvement of catalytic activity, a catalyst performed exceeding catalytic volcano plots is desired, while it is impeded by the adsorption-energy scaling relations of reaction intermediates. Numerous efforts have been focused on optimizing the initial and final intermediates to circumvent the scaling relations for an improved performance. For a step forward, simultaneously optimizing all intermediates is essential to explore the theoretical maximum of catalytic activity. Herein, we proposed a dynamic adsorption mechanism (DAM) to independently regulate the adsorption configurations of all intermediates of electrochemical nitrogen reduction reaction (NRR). To demonstrate the DAM, a multi-site NbNi3 intermetallic is developed, which enables suitable adsorption energies of different intermediates via modulating orbital coupling mechanisms. As a result, NbNi3 achieves an ultra-low limiting potential of NRR of -0.11 V vs. reversible hydrogen electrode (RHE). Strikingly, the theoretical result is confirmed by a proof-of-concept experiment, wherein the nanoporous NbNi3 electrode exhibits a remarkable NH3 yield rate of 25.89 μg h-1 cm-2 with the Faradic efficiency of 33.15% at -0.25 V vs. RHE. Overall, this work brings out a new strategy to avoid the scaling relations, and opens up a promising avenue toward high-efficiency NRR catalysts.

Biomimetic Elastic Single-Atom Protrusions Enhance Ammonia Electrosynthesis.

Electrocatalytic nitrogen (N2) reduction reaction (eNRR) is a promising route for sustainable ammonia (NH3) generation, but the eNRR efficiency is dramatically impeded by the sluggish reaction kinetics. Herein, inspired by the dynamic extension-contraction of sea anemone tentacles in response to environmental changes, we propose a biomimetic elastic Mo single-atom protrusion on vanadium oxide support (pSA Mo/VOH) electrocatalyst featuring a symmetry-breaking Mo site and an elastic Mo-O4 pyramid for efficient eNRR. In-situ spectroscopy and theoretical calculations reveal that the protruding Mo-induced symmetry-breaking structure optimizes the d electron filling of Mo, enhancing the back-donation to the π* antibonding orbital, effectively polarizing the N≡N bond and reducing the barrier from *N2 to *N2H. Notably, the elastic Mo-O4 pyramidal structure of pSA Mo provides a dynamic Mo-O microenvironment during continuous eNRR processes. This optimizes the electronic structure of the Mo sites based on different reaction intermediates, enhancing the adsorption of various N intermediates and maintaining low barriers throughout the six-step hydrogenation process. Consequently, the elastic pSA Mo/VOH exhibits an excellent NH3 yield rate of 50.71 ± 1.12 μg h-1 mg-1 and a Faradaic efficiency of 35.38 ± 1.03%, outperforming most electrocatalysts.

Biomimetic Elastic Single‐Atom Protrusions Enhance Ammonia Electrosynthesis

Electrocatalytic nitrogen (N2) reduction reaction (eNRR) is a promising route for sustainable ammonia (NH3) generation, but the eNRR efficiency is dramatically impeded by the sluggish reaction kinetics. Herein, inspired by the dynamic extension‐contraction of sea anemone tentacles in response to environmental changes, we propose a biomimetic elastic Mo single‐atom protrusion on vanadium oxide support (pSA Mo/VOH) electrocatalyst featuring a symmetry‐breaking Mo site and an elastic Mo−O4 pyramid for efficient eNRR. In‐situ spectroscopy and theoretical calculations reveal that the protruding Mo‐induced symmetry‐breaking structure optimizes the d electron filling of Mo, enhancing the back‐donation to the π* antibonding orbital, effectively polarizing the N≡N bond and reducing the barrier from *N2 to *N2H. Notably, the elastic Mo−O4 pyramidal structure of pSA Mo provides a dynamic Mo−O microenvironment during continuous eNRR processes. This optimizes the electronic structure of the Mo sites based on different reaction intermediates, enhancing the adsorption of various N intermediates and maintaining low barriers throughout the six‐step hydrogenation process. Consequently, the elastic pSA Mo/VOH exhibits an excellent NH3 yield rate of 50.71 ± 1.12 μg h−1 mg−1 and a Faradaic efficiency of 35.38 ± 1.03%, outperforming most electrocatalysts.

Electrochemical Synthesis of Metasequoia-Like Reduced Graphene Oxide Coated Cobalt-Silver Catalyst for Stable and Efficient Electrocatalytic Nitrate Reduction to Ammonia.

Electrocatalytic nitrate (NO3 -) reduction to ammonia (NH3) is a green and efficient NH3synthesis technology. Metallic silver (Ag) is one of the well-known electrocatalysts for NO3 - reduction. However, under alkaline conditions, its poor water-splitting ability fails to provide sufficient protonic hydrogen required for NH3 synthesis, resulting in low NH3 selectivity. Additionally, metal catalysts are prone to leaching and oxidation during electrocatalysis, resulting in poor stability. Herein, cobalt (Co) into Ag (CoAg) catalyst is doped, which not only increases the NH3 selectivity by 34.4%, but also reduces the reduction potential by 0.1V. Meanwhile, reduced graphene oxide (rGO) as a protective "armor" is used to encapsulate the CoAg catalyst (rGO2.92@CoAg). The rGO2.92@CoAg catalyst shows excellent stability for over 300 hours (h) of continuous reaction. The Co and Ag contents in the rGO2.92@CoAg catalyst after continuous tests decreases by only 4.3% and 3.1%, respectively, which are much lower than those of the CoAg catalyst without the rGO (90.8%, 52.6%). Moreover, the rGO2.92@CoAg catalyst shows high Faradaic efficiency (99.3%) and NH3 yield rate (1.47mmol h-1 cm-2). Therefore, a high performance and strong stability rGO2.92@CoAg catalyst is obtained by Co doping and rGO coating, which provides theoretical basis for practical industrial application.

Construction of electron-deficient Co on the nanoarrays enhances absorption and direct electron transfer to accelerate electrochemical nitrate reduction

Electrochemical nitrate reduction is a promising remediation strategy for nitrate-contaminated wastewater treatment, in which nitrate adsorption is a prerequisite step in the overall process. Herein, the iron-induced cobalt phosphide was grown in situ on porous nickel foam (Fe-CoP/NF) for the electrochemical nitrate reduction. Structural characterization verified doping of Fe and the uniform nanotube arrays of Fe0.03CoP/NF. Remarkably, the Fe0.03CoP/NF exhibited a high efficiency nitrate removal efficiency (99.3%) and excellent ammonia selectivity (100% selectivity and 0.485mg·h-1cm-2 NH3 yield rate). Both experimental and theoretical results reveal that Fe doping alters the local charge distribution of the Co active centers to form electron-deficient Co. The Co electron-deficient regions were constructed due to the difference in electronegativity between Co and Fe. Furthermore, the formation of electron-deficient centers facilitates the reduction of charge transfer resistance. In particular, Fe0.03CoP/NF maintained an excellent conversion efficiency of nitrate to N2 (99.8%) with 60mM Cl−, and the selectivity of N2 is maintained above 99.1% during long-term operation. This system possesses a low electrical consumption of 1.79 kWh·molN-1. This study designed an enhanced electrocatalyst through enhanced nitrate absorption and direct electron transfer strategies, thus providing a promising and low-power consumption approach for addressing nitrate pollution.

Iron and nickel based alloy nanoparticles anchored on phosphorus-modified carbon-nitrogen plane enhances electrochemical nitrate reduction to ammonia

The catalysts of iron and nickel nanoparticles anchored on carbon–nitrogen plane (FeNi-CN) are considered as the potential candidates for promising electrochemical nitrate reduction to ammonia (ENO3RR). However, the high d-orbital energy levels of iron and nickel sites coordinated with nitrogen atoms often lead to overly strong adsorption of reaction intermediates on active sites, severely limiting the improvement of catalytic performance. Herein, a catalyst FeNi3@P-NC consisting FeNi3 alloy nanoparticles confined in phosphorus (P)-modified carbon–nitrogen plane is successfully fabricated, where the electron withdrawal effect induced by P on the carbon–nitrogen plane decreases the d-orbital energy, and optimizes the d-band center of FeNi alloy, thus weakening the overly strong adsorption of intermediates at the metal-N sites and thereby improving NO3RR activity. The prepared FeNi3@P-NC catalyst exhibits exceptional NO3RR performance with a 93 ± 4.5 % Faradaic efficiency of NH3 production (FENH3) and a high NH3 yield rate (YNH3) of 9633 ± 227.3 μg h−1 cm−2 at −0.7 V versus Reversible Hydrogen Electrode (vs. RHE) under alkaline medium. Importantly, FeNi3@P-NC also demonstrates superior catalytic stability and durability, which maintains stability over twenty-five successive electrochemical cycles and for 50 h of continuous electrolysis at 100 mA cm−2.

A Newly Predicted Magnetic TMB6 Monolayer for Efficient Nitrogen Fixation.

Developing electrocatalysts for the N2 reduction reaction (NRR) with high activity, high selectivity, and low cost is urgently required to enhance the NH3 yield rate. Based on first-principles calculations, we predict a series of new transition metal boride TMB6 (TM = Ti, V, Cr, Mn, Fe, and Co) monolayers and investigate their magnetoelectronic and electrocatalytic properties. The results reveal that VB6 and CoB6 favor ferromagnetic coupling, while TiB6, CrB6, MnB6, and FeB6 display antiferromagnetic ordering. Furthermore, TiB6 exhibits a high Néel temperature of 344 K and a large magnetic anisotropy energy of 614 μeV per Ti atom. Most interestingly, TiB6 and VB6 exhibit superior NRR catalytic activity with a limiting potential of -0.50 and -0.19 V, respectively, and favorable NRR selectivity over the HER. Finally, the structural stability of TMB6 monolayers has been confirmed by a set of phonon dispersion, molecular dynamics, and elastic constant calculations. Our results highlight the use of the newly designed two-dimensional (2D) TM borides as promising candidates for spintronic devices and nitrogen fixation applications.

Modulating Nitrogen Adsorption Mode and Microenvironment of Active Sites for Boosting Electrochemical Nitrogen Reduction.

Electrochemical reduction of N2(NRR) offers a sustainable approach for ammonia (NH3) synthesis, serving as a complementary to the traditional emission- and energy-intensive Haber-Bosch process. However, it faces challenges in N2 activation and competing with pronounced hydrogen evolution reaction (HER). Herein an efficient electrocatalyst comprised of ultrafine Ru nanoclusters (NCs) confined by a hydrophobic molecular layer is developed on the surface of 2D Ti3C2Tx for NRR. These experimental and theoretical calculation results demonstrate that 1) ultrafine Ru NCs dispersed on the Ti3C2Tx surface form paired active sites for N2 chemisorption in a unique tilted configuration with low-energy activation 2) the hydrophobic molecular layer modulates the local microenvironment surrounding catalytically active sites, enabling efficient N2 accumulation while repelling H2O diffusion to the active sites on the Ti3C2Tx surface, thereby leading to an increased N2 concentration and suppressed HER. As a result, an exceptionally high NH3 yield rate of 33.5µg h-1mg-1cat and Faradaic efficiency of 65.3% are obtained at -0.25V versus reversible hydrogen electrode (RHE) in 0.1m Na2SO4, outperforming those previously reported Ti3C2Tx-derived electrocatalysts. This work provides a valuable strategy for the rational design of advanced electrocatalysts by manipulating active sites and local microenvironments for efficient electrocatalysis.

Coherent NiS2@SnS2nanosheet for accelerating electrocatalytic nitrate reduction to ammonia.

The development of an effective and selective catalyst is the key to improving the multi-electron transfer nitrate reduction reaction (NO3-RR) to ammonia. Here, we synthesized a coherent NiS2@SnS2nanosheet catalyst loaded on carbon cloth via one-step solvothermal method. Experimental data reveals that the integration of NiS2and SnS2can enhance the NO3-RR performance in terms of high NH3yield rate of 408.2μg h-1cm-2and Faradaic efficiency of 89.61%, as well as satisfying cycling and long-time stability.

Promoted Two-Step Ammonia Synthesis with CoOOH/Co foam at Ampere-Level Current Density and Nearly 100% Faraday Efficiency from Air and Water.

Ammonia (NH3) is regarded as an essential hydrogen storage material in the new energy field, and plasma-electrocatalytic synthesis of NH3 (PESA) is an alternative to the traditional Haber-Bosch process. Here, a bifunctional catalyst CoOOH/CF is proposed to enhance the PESA process. Benefiting from the efficient activation of O2 by CoOOH/CF, NOx - yield rate can reach the highest value of 171.90mmol h-1 to date. Additionally, CoOOH holds a more negative d-band center, thereby exhibiting weaker adsorption toward NO*, lowering the energy barrier for the rate determining step, resulting in a high NH3 yield rate (302.55mg h-1 cm-2 at -0.8V) with ampere-level NH3 current density (2.86 A cm-2 at -0.8V) and nearly 100% Faraday efficiency (FE, 99.8% at -0.6V). Moreover, CoOOH/CF achieves an excellent 4.54g h-1 NH3 yield rate with 97.9% FE in an enlarged electrolyzer, demonstrating the feasibility of PESA on a large scale.

Enrichment of Active Hydrogen at Amorphous CoO/Cu2O Heterojunction Interfaces Enhances Electrocatalytic Nitrate Reduction to Ammonia.

The reduction of nitrate into valuable ammonia via electrocatalysis offers a green and sustainable synthetic pathway for ammonia. The electrocatalytic nitrate reduction reaction (NO3RR) encompasses two crucial reaction steps: nitrate deoxygenation and nitrite hydrogenation. Notably, the nitrite hydrogenation reaction is regarded as the rate-determining step of the process. Herein, the amorphous CoO support introduced for the construction of the a-CoO/Cu2O tandem catalyst provides sufficient active hydrogen and synergistically catalyzes the NO3RR. The a-CoO/Cu2O catalyst showed excellent performance with a maximum NH3 Faradaic efficiency of 95.72% and a maximum yield rate of 0.96mmol h-1 mgcat -1 at -0.4V. In the flow cell, the maximum NH3 yield rate of 12.14mmol h-1 mgcat -1 is achieved at -800mA. The high NO3RR activity of a-CoO/Cu2O is attributed to the synergistic cascade effect of amorphous CoO and Cu2O at the heterojunction interface, where Cu2O serves as the adsorption site for NO3 -, while the accelerated active hydrogen generation of amorphous CoO promotes the nitrite hydrogenation reaction. This work provides a strategy for designing multi-site cascade catalysts centered on amorphous structures to achieve efficient NO3RR.

Electrochemical production of ammonia: Nitrate reduction over novel Cu-Ni-Al metallic glass nanoparticles used as highly active and durable catalyst

It is a great challenge to design and synthesize catalysts that can regulate both adsorption and desorption processes for electrocatalytic nitrate reduction to ammonia (NRA). Herein, amorphous Cu-Ni-Al nanometallic glasses (NG) were synthesized using a facile thermal evaporation coupled Joule heating method. The Cu50Ni25Al25-NG exhibits remarkable Faradaic efficiency (98.81 %) and NH3 yield-rate (211.14 μmol h−1cm−2) at an outstanding positive potential of −0.15 V vs. RHE. Aluminum atoms of low work-function when intercalated at different positions in Cu50Ni25Al25-NG enhance both adsorption and desorption processes during NRA. The oscillatory properties of surface potential detected by Kelvin-probe force microscopy demonstrate the diversity of active sites on Cu50Ni25Al25-NG. Two potential-regulated reaction mechanisms in NRA on the surface of Cu50Ni25Al25-NG were proposed using in-situ electrochemical Raman spectra. This work provides a new method for the preparation of multi-element NG enriched with low work-function metals and a new idea for the synthesis of synergistic catalytic-sites for NRAs.

Surface electronic fine-perturbation driven by distal atom coupling at W-Se pair sites for enhanced ammonia synthesis

Engineering single-atom electrocatalysts (SACs) of geometries and electronic structures at atomic level to overcome the critical trade-off in catalytic performance remains a significant challenge. Here, we report a novel metal–nonmetal pair sites with non-bonding interaction to achieve dual enhancements of activity and selectivity for nitrogen reduction reaction (NRR). The stable non-bonding structure of W-Se atom pairs on C3N4 support (W-SeC3N4) was engineered by photo-assisted cryogenic reduction. Distal Se-atom coupling drives a fine-tuning of surface-localized electronic state on center W-atom through genuine chemical interaction and modulates the adsorption energies of intermediates like *NNH, *NH and *NH2. W-SeC3N4 thus demonstrates a NH3 yield rate of 74.6 ug h−1 mgcat−1 and >38.2 % selectivity, surpassing all current non-precious metal SACs. Our work supplies an advanced strategy for the rational design of SACs in complex chemical reactions involving multi-step intermediates.

Integrating few-atom layer metal on high-entropy alloys to catalyze nitrate reduction in tandem

While high-entropy alloy (HEA) catalysts seem to have the potential to break linear scaling relationships (LSRs) due to their structural complexity, the weighted averaging of properties among multiple principal components actually makes it challenging to diverge from the symmetry dependencies imposed by the LSRs. Herein, we develop a ‘surface entropy reduction’ method to induce the exsolution of a component with weak affinity for others, resulting in the formation of few-atom-layer metal (FL-M) on the surface of HEAs. These exsolved FL-M surpass the confines of the original configurational space of conventional HEAs, and collaborate with the HEA substrate, serving as geometrically separated active sites for multiple intermediates in a complex reaction. This FL-M-covered HEA shows an outstanding performance for electrocatalytic reduction of nitrate to ammonia (NH3) with a Faradaic efficiency of 92.7%, an NH3 yield rate of 2.45 mmol h–1 mgcat.–1, and high long-term stability (>200 h). Our work achieves the precise manipulation of atomic arrangement, thereby expanding both the chemical space occupied by known HEA catalysts and their potential application scenarios.

Rapid Fabrication of N-, Cu-, and Co-Doped Electrodes with Strong Electronic Coupling by Cold Plasma for Electrocatalytic Reduction of Nitrate to Ammonia.

Electrochemical NOx- reduction (NOxRR) is a sustainable technology for ammonia synthesis. The development of a simple, fast, and economical catalytic electrode preparation technique is crucial for large-scale ammonia synthesis. Herein, we propose a plate-to-plate DBD plasma strategy to synthesize the catalytic electrodes M-N/CP (M = Cu, Co, Ni, CuCo, and CuNi), achieving in suit codoping of N and bimetals on carbon paper (CP) at room temperature within 3 h. N-doping improves the metal loading and the NOxRR performance by forming N-M bonds. The electronic coupling and synergistic effect of Cu and Co sites facilitate the relay conversion of NO3- to NO2- to NH3. Notably, the NO3- removal efficiency of CuCo-N/CP reaches 82%, with NH3 yield rate of 346 μg h-1 cm-2, and the faradaic efficiency is as high as 86% at -0.58 V vs RHE, which remains competitive in terms of NOxRR performance. Importantly, wet flue gas denitrification and desulfurization coupled with electrocatalytic reduction can convert NOx and SO2 to (NH4)2SO4, Additionally, the maneuverability of plasma technology offers the potential for batch preparation of CuCo-N/CP electrodes for electrochemically driven wet denitrification wastewater valorization.

Electrocatalytic nitrite conversion to ammonia over Mn single atoms anchored on MoO3-x

Electrocatalytic reduction of NO2 to NH3 (NO2RR) offers a promising route to attain harmful NO2– removal and valuable NH3 production. Herein, Mn single atoms anchored on oxygen vacancy-rich MoO3-x (Mn1/MoO3-x) are developed as a high-performance catalyst for the NO2RR. Atom characterizations unravel that the isolated Mn atoms exist as Mn1-O5 moieties on MoO3-x. Theoretical calculations and in situ electrochemical spectroscopic measurements unveil that Mn1/MoO3-x follows a Langmuir-Hinshelwood mechanism to drive the NO2RR process, in which Mn1-O5 site facilitates the adsorption and activation of NO2– to form the intermediates, while MoO3-x substrate dissociates H2O to yield *H. The generated *H is then transferred from MoO3-x substrate to Mn1-O5 site which promotes the intermediate protonation to produce NH3. Remarkably, Mn1/MoO3-x in flow cell reaches the high NH3 yield rate of 546.25 μmol h−1 cm−2 and NH3-Faraday efficiency of 92.6 %, outperforming most reported NO2RR catalysts.

Efficient nitrite-to-ammonia electroreduction on single Ag sites

Electroreduction of nitrite to ammonia (NO2RR) provides an innovative route for simultaneously achieving waste NO2– removal and valuable NH3 production. Herein, single-atom Ag on hexagonal BN nanosheets (Ag1@h-BN) is developed as an efficient catalyst for the NO2RR. Strikingly, Ag1@h-BN assembled in a flow cell shows the highest NH3-Faradaic efficiency of 92.04 % with the corresponding NH3 yield rate of 1523.6 μmol h−1 cm−2 at a high current density of 266.2 mA cm−2. Theoretical calculations and electrochemical spectroscopic measurements unveil the creation of Ag1-N3 site to selectively activate NO2– and boost the hydrogenation energetics of NO2–-to-NH3 pathway, consequently resulting in the substantially expedited selectivity and activity of Ag1@h-BN for the NO2RR.

Two-dimensional Boridene Nanosheets for Efficient Electrochemical Nitrogen Fixation under Ambient Conditions.

The carbon-free electrocatalytic nitrogen reduction reaction (NRR) is an alternative technology to the current Haber-Bosch method, that can be conducted under ambient conditions, and directly converting water and nitrogen (N₂) into ammonia (NH₃). However, the limited activity and selectivity of NH₃ electrosynthesis hinder the practical applications of NRR. In this study, we present a novel type of electrocatalyst called boridene nanosheets enriched with metal vacancies that are specifically designed for efficient electrocatalytic NRR under ambient conditions. Electrochemical testing in a 0.1 M phosphate-buffered saline (PBS) electrolyte demonstrates that boridene exhibits a high Faradaic efficiency of 66.7% for NH₃ production at -0.2 V vs. RHE, with a maximum NH₃ yield rate of 23.6 µg h-1 mg cat-1 at -0.4 V vs. RHE. Durability tests show that boridene maintains significant stability throughout multiple cycles of NRR. Mechanistic insights are obtained through in situ FTIR spectroscopy, revealing that boridene exhibits a preference for the distal pathway during the process of NRR. These findings highlight the potential of boridene as an efficient and stable catalyst for sustainable NH₃ synthesis.

Conversion of Nitrate to Ammonia by Amidinothiourea-Coordinated Metal Molecular Electrocatalysts with d-π Conjugation.

The electrochemical reduction of nitrate to ammonia (NO3RR) provides a desired alternative of the traditional Haber-Bosch route for ammonia production, igniting a research boom in the development of electrocatalysts with high activity. Among them, molecular electrocatalysts hold considerable promise for the NO3RR, suppressing the competing hydrogen evolution reaction. However, the complicated synthesis procedure, usage of environmentally unfriendly organic solvents, and poor stability of Cu-based molecular electrocatalysts greatly limit their employment in NO3RR, and the development of desired Cu-based molecular catalysts remains challenging. Herein, a simple nonorganic solvent involving a one-step strategy was proposed to synthesize d-π-conjugated molecular electrocatalysts metal-amidinothiourea (M-ATU). Cu-ATU is composed of Cu coordinated with two S and two N atoms, whereas Ni-ATU is formed by Ni with four N atoms from two ATU ligands. Remarkably, Cu-ATU with a Cu-N2S2 coordination configuration exhibits superior NO3RR activity with a NH3 yield rate of 159.8 mg h-1 mgcat-1 (-1.54 V) and Faradaic efficiency of 91.7% (-1.34 V), outperforming previously reported molecular catalysts. Compared to Ni-ATU, Cu-ATU transfers more electrons to the *NO intermediate, effectively breaking the strong sp2 hybridization system and weakening the energy of N═O bonds. The increase in free energy of *NO reduced the energy barriers of the rate-determining step, facilitating the further hydrogenation process over Cu-ATU. Our work opened up a new horizon for exploring molecular electrocatalysts for nitrate activation and paved a way for the in-depth understanding of catalytic behaviors, aligning more closely with industrial demands.