Formation Of NH Research Articles

Boosting nitrate electroreduction to ammonia on NbOxvia constructing oxygen vacancies

A NbOx catalyst with oxygen vacancies is synthesized and used for nitrate electroreduction to ammonia. The faradaic efficiency of 94.5% and the NH3 formation rate of 55.0 μg h−1 mgcat−1 can be achieved in a neutral electrolyte.

A photo-assisted electrochemical-based demonstrator for green ammonia synthesis

Bridging laboratory research and practical utilization is of crucial importance for the development of green ammonia synthetic technologies. A decentralized photo-assisted electrochemical-based demonstrator has been proposed for green ammonia synthesis from renewable electricity, air and water, where well-known defect-laden WO3 is used as the working electrode, and a commercially available PV panel supplies renewable electricity. In this demonstrator, defect-laden WO3 exhibits the optimum electrochemical NH3 formation rate (4.51 × 10–12 mol s−1 cm−2) in 0.1 M K2SO4 in a photovoltaic electrochemical (PV-EC) system. A system-level energy and cost analysis was conducted to investigate its economic viability and a general evaluation tool for system performance and cost estimation was proposed. This advance enables the possibility of integrating the small-scale green ammonia demonstrator into a stand-alone farm system.

Low-temperature preparation of cupric spinel for room-temperature removal of hydrogen sulfide to value-added product ammonia formation

Spinel-type compounds are extremely effective in the adsorptive removal of gas pollutants. However, they are prepared at high temperatures, and their lack of catalytic production of value-added products deserves further research. This study focused on the preparation of cupric spinel compounds at low temperatures and their application to H2S removal with value-added product formation. Cupric spinel (CuFe2O4) was prepared by the co-precipitation of bivalent copper and trivalent iron at 60 °C, which allowed the formation of CuFe2O4 with a high surface area of 202.72 m2/g. The obtained breakthrough capacity was 5.68 mg H2S/g in ambient temperature removal of H2S. The analysis of outflowing gas by online sensor demonstrated the formation of 73.75 mg NH3/g spinel compound. The sulfide compound presented in the sample analysis supported the NH3 formation at the end of H2S removal, that is, NH3 was synthesized at ambient temperature after the formation of sulfide compound. Successfully prepared the CuFe2O4 at a low temperature and its application on H2S removal with value added product NH3 formation achieved at ambient temperature.

Insight into the influence of K on the adsorption performance and reaction pathways of CeO2/TiO2 catalyst

K species can cause severe deactivation of CeO2/TiO2 NH3-SCR catalyst. In this work, the effects of K on the adsorption and activation of reactive species, the evolution of intermediates, and the surface reactions on the CT catalyst were systematically studied using DFT calculations. The adsorption of K caused the recombination of surface electrons, resulting in the active sites Ce and O getting electrons from K and becoming less reactive, which inhibited the adsorption and activation of NH3. The presence of K could promote the adsorption of NO and O2, and the decomposition of O2. But most of the adsorbed NO and O2 would transform into inactive NOx species, and then cover the active sites on the surface. The continuous dehydrogenation reaction of NH3 was suppressed, thereby hindering the formation of NH2. The formation and decomposition of the intermediate NH2NO were both inhibited, which seriously affected the reduction of NO. In addition, the formation of NO2 involved in the fast-SCR reaction was inhibited, which is the main reason for the deactivation of CT catalysts at low temperatures.

Competitive inhibition of catalytic nitrate reduction over Cu–Pd-hematite by groundwater oxyanions

The presence of various oxyanions in the groundwater could be the main challenge for the successive application of Cu–Pd-hematite bimetallic catalyst to aqueous NO3− reduction due to the inhibition of its catalytic reactivity and alteration of product selectivity. The batch experiments showed that the reduction kinetics of NO3− was strongly suppressed by ClO4−, PO43−, BrO3− and SO32− at low concentrations (>5 mg/L) and HCO3−, CO32−, SO42− and Cl− at high concentrations (20–500 mg/L). The presence of anions significantly changing the end-product selectivities influenced high N2 selectivity. The selectivity toward N2 increased from 55% to 60%, 60%, and 70% as the concentrations of PO43−, SO32−, and SO42− increased, respectively. It decreased from 55% to 35% in the presence of HCO3− and CO32− in their concentration range of 0–500 mg/L. The production of NO2− was generally not detected, while the formation of NH4+ was observed as the second by-product. It was found that the presence of oxyanions in the NO3− reduction influenced the reactivity and selectivity of bimetallic catalysts by i) competing for active sites (PO43−, SO32−, and BrO3− cases) due to their similar structure, ii) blockage of the promoter and/or noble metal (HCO3−, CO32−, SO42−, Cl− and ClO4− cases), and iii) interaction with the support surface (PO43− case). The results can provide a new insight for the successful application of catalytic NO3− reduction technology with high N2 selectivity to the contaminated groundwater system.

Green production of ammonia from nitrogen-rich biomass pyrolysis: Evolution of fuel-N under H2-rich atmosphere

Ammonia (NH3) is an emerging carbon-free energy carrier. A sustainable route for NH3 production is proposed in this work via pyrolysis process of nitrogen-rich renewable resources. Microalgae, the carbon-neutral and renewable resource with a high content of nitrogen, were selected in this work. H2 was used as a reinforcing agent to enhance NH3 production. The influence of H2 on the fuel‑nitrogen transfer during the microalgae pyrolysis was experimentally investigated. The formation and conversion pathways of the N-containing species in bio-char, bio-oil and gaseous products were evaluated. Results indicate that H2 promotes the nitrogen transformation into gaseous products, while reduces the contents of the nitrogen in solid char and bio-oil. Meanwhile, H2 greatly promotes the conversion of protein-N to pyridinic-N, pyrrolic-N and quaternary-N in biochar, but also facilities the formation of N-heterocyclic compounds in bio-oil. Pyrolysis temperature is an important factor affecting the distribution and conversion of N-containing species. NH3 and HCN yields increase gradually with temperature. H2 is beneficial for the thermal cracking of stable proteins, the deamination of amides, and the ring-opening of N-heterocyclic species, thereby facilitating the formation of NH3. The highest NH3 yield of 37.34 wt% is obtained at 800 °C under 15%H2 + 85%Ar atmosphere.

Plasma-assisted ammonia synthesis in a packed-bed dielectric barrier discharge reactor: effect of argon addition

The effect of argon (Ar) addition on plasma-assisted ammonia (NH3) synthesis in a packed-bed dielectric barrier discharge (DBD) reactor is investigated in this work. Both higher normalized NH3 concentration and N2 conversion are achieved by adding Ar to N2–H2 plasma. The 18.6% increment of normalized NH3 concentration and 15% increment of N2 conversion are realized with 30 vol.% Ar addition compared with the case of N2–H2 plasma only, indicating that Ar addition would contribute to NH3 formation. The mechanisms of NH3 synthesis with Ar addition are proposed based on electrical characteristics and electron energy distribution function of the N2–H2–Ar plasma. The intensity of microdischarges, mean electron energy and quantity of energetic electrons increase upon Ar addition. Hence, the electron-impact reactions would be enhanced upon Ar addition. Meanwhile, the effective capacitance of the plasma reactor is improved, which suggests Ar addition contributes to achieve fully-bridged plasma discharge and transfer energy into chemical process in plasma. Moreover, the presence of Ar introduces Penning excitation and ionization reactions in N2-H2 plasma, which would benefit N2 conversion and then accelerate NH3 formation as well.

Emission of NH3 and N2O during NO reduction over commercial aged three-way catalyst (TWC): Role of individual reductants in simulated exhausts

The NH3 and N2O emissions over commercial aged three-way catalysts (TWC) is closely dependent on individual reductant species in a complex reaction network. Under simulated full mixture feed composition containing CO, H2 and a hydrocarbon mixture of C3H6 and C3H8 as reductants, the NH3 formation was maximized under rich conditions (0.97 ≤ λ < 1.00) at high temperature ranges from 350 to 500 °C. The N2O formation was more pronounced under a stoichiometric condition (λ = 1.00) at low temperatures from 250 to 350 °C. To determine the role of individual reductant species in NH3 and N2O emissions characterized from full feed conditions, we conducted simple feed tests containing a single reductant (H2, CO or C3H6) and NO. It was found that NH3 is mainly generated through the NOH2 reaction via -NH2 intermediates when H2 is present in the feed gas under the stoichiometric condition. On the other hand, the role of H2 on the N2O formation is mainly low temperature reactions below 200 °C. The major contribution of the N2O formation at warmed-up temperatures is the CONO reaction forming surface NCO- species, where additional surface CO and H2 species can be also produced by steam reforming of C3H6.

Interface hydrophobic tunnel engineering: A general strategy to boost electrochemical conversion of N2 to NH3

Electrocatalytic nitrogen reduction reaction (NRR), which can produce ammonia from N2 and H2O under ambient conditions, has emerged as a promising sustainable alternative to the Haber-Bosch (H-B) process. However, their unsatisfied conversion efficiency and selectivity severely restrict the real utilization of NRR, owing to the stubborn triple bond in the N2 molecule and the competitive hydrogen evolution reaction (HER). Here, inspired from the local microenvironment of the nitrogenase, we report for the first time a facile and general strategy to boost the NRR selectivity and activity through the self-assembled monolayer (SAM) of hexanethiol (HEX) on a series of metal electrocatalysts (Cu, Au, Pt, Pd and Ni). Molecular dynamics (MD) simulations suggest that the HEX SAM provides a hydrophobic microenvironment to impede the diffusion and adsorption of water molecules and promote that of N2 molecules, thus inhibiting HER and simultaneously improving the NRR performance. Notably, among all the prepared samples, the highest Faradic efficiency (FE) of 50.5% is achieved on Cu-HEX with NH3 formation rate (R) of 1.2 μg h−1 cm−2. Remarkably, for the HER-favored Pt catalyst, the highest R of 26.4 μg h−1 cm−2 is also achieved on Pt-HEX with FE of 1.8% under 1 cm2 of electrode area. The present strategy not only represents a general diffusion-controlled method to engineer high-performance NRR electrocatalysts, but also provides a new insight into the effect of surface chemistry of catalysts on the NRR process and kinetics.

Homogeneous Ni(I)tetra Sulfonated Phthalocyanine Electrocatalyst Generated at Low Overpotential Clubbed with a Wet‐Scrubbing Column for High Efficiency NO Reduction to NH3

AbstractAlthough the degradation of NO gas to a less toxic form is a promising strategy to help solve atmospheric health and ozone depletion problems, conversion to a useful gas is a recent strategy. The generation of NH3 from NO with high efficiency per catalyst area or weight is in the early stages. In this investigation, a tetra sulfonated phthalocyanine with a Ni(II) (Ni(II)TSPc) complex was used to produce a low valent homogenous electrocatalyst Ni(I)TSPc in an alkaline medium at a lower overpotential. Ni(I)TSPc formation at a lower overpotential was demonstrated by the initial change in oxidation/reduction potential from 25 mV to −360 mV during electrolysis, peak potential change in cyclic voltammetry, and UV‐Vis spectral analysis. A potentiometric titration method used to quantify the electrogenerated Ni(I)TSPc revealed 90 % efficiency in 1 h. The decrease of Ni(I)TSPc concentration when contacting NO gas at the wet scrubber column showed that the NO removal process followed a Ni(I)TSPc (Ni(I)) mediation or mediated electrocatalytic reduction (MER) process. The NO removal efficiency reached almost 100 % at a 0.2 L/min gas flow rate of 20 ppm. The selective formation of NH3 with a maximum of 1492 μmol/g Ni(I) was achieved for the first time in the homogeneous electrocatalytic reduction process. The developed process generated NH3 from NO gas and has the potential for scale‐up.

The role of tungsten chemical state and boron on ammonia formation using N2–H2 radiofrequency discharges

This work aims at investigating the role of tungsten and boron surfaces on ammonia production with N2–H2 radiofrequency plasmas at 3 Pa. The experiments combine the analysis of the reaction products and surface chemical environment using mass spectrometry and x-ray photoelectron spectroscopy (XPS). We show that NH3 is formed upon discharges of N2 or H2 after having exposed a tungsten (W) foil to H2 or N2, respectively. A higher amount of ammonia is formed for the N2-then-H2 case, which we explain by the larger number of Eley–Rideal reaction channels for the formation of NH x (s) and the lower surface diffusion barrier for adsorbed hydrogen, calculated using the density functional theory (DFT). As a result, H(s) combines with N(s) or NH x (s) through Langmuir–Hinshelwood at a faster rate than N(s) combines with another N(s). The amount of NH3 formed with N2–H2 discharges after conditioning the tungsten foil with H2, N2 or O2 was also investigated. We observed that this pre-conditioning plays no major role on the amount of NH3 detected with the residual gas analyser, albeit a small decrease was observed after H2 contamination. With DFT, the adsorption energies of H on WO3 and W are found to be similar, while the adsorption of N on WO3 is significantly weaker. The similar NH3 concentrations obtained with a clean and oxidized tungsten surface thus suggest that the adsorption of N does not limit the formation rate of ammonia. The production of NH3 on boron was evaluated as well. The boron surface reduced the amount of detected ammonia almost by half. On the one side, a significant amount of H2 was removed from the surface during the Ar cleaning that followed, which suggests a strong retention of hydrogen. On the other side, the XPS data reveals that nitrogen forms strong bonds with boron and impurities on the surface, regardless on whether hydrogen is previously present on the surface or in the plasma volume. The presence of hydrogen in the plasma volume, simultaneously with nitrogen or after nitrogen exposure, is nevertheless necessary for the formation of NH(s) and NH2(s). No NH3(s) was however detected with XPS. The increased retention of both hydrogen and nitrogen on the boron surface may thus hinder the formation of NH3.

Stable isotopes provide insight into sources and cycling of N compounds in the Sacramento-San Joaquin Delta, California, USA

River deltas and their diverse array of aquatic environments are increasingly impacted by anthropogenic inputs of nitrogen (N). These inputs can alter the N biogeochemistry of these systems and promote undesirable phenomena including harmful algae blooms and invasive aquatic macrophytes. To examine N sources and biogeochemical processes in the Sacramento-San Joaquin Delta, a river delta located in central California, USA, that is fed primarily by the Sacramento River, we utilized a multi-tracer approach that measured N species concentrations and stable isotope values monthly from April 2011 to November 2012 in samples collected from the channelized mainstem of the Sacramento River, two channelized distributaries of the Sacramento River, and the Cache Slough Complex, a network of Sacramento River tributaries and shallow water wetland habitat. We found that the Sacramento River and its channelized distributaries received N primarily in the form of NH4+ from treated wastewater effluent and that NH4+ was lost rapidly while NO3− was gained more slowly during subsequent downstream transit, driven by an array of biogeochemical processes whose identities could be constrained via examination of stable isotope values. The Cache Slough Complex, which was characterized by lower net flows and higher water residence times than the Sacramento River and its distributaries, received variable inputs of low conductivity water elevated in NH4+ from the Sacramento River and higher conductivity water elevated in NO3− from landward tributaries. Deviations from expected conservative mixing of these sources were spatially variable but broadly indicative of local inputs of treated wastewater effluent NO3−, conversion of Sacramento River NH4+ to NO3− via nitrification, uptake of NH4+ and NO3− by phytoplankton, and remineralization of organic N. These findings highlight both the diversity in N dynamics in anthropogenically impacted river delta environments and the utility of a multi-tracer approach in constraining these processes in such complex systems.

Study on the pyrolysis behavior of coal-water slurry and coal-oil-water slurry

In this work, different concentrations of coal-water slurry and coal-oil-water slurry were prepared and pyrolyzed at various temperatures of 800–1000 °C. The chemical characteristics and combustion reactivities of chars and the formation mechanism of main gas components of CO, CO2, CH4, and H2 were investigated. With the water content of the coal-water slurry increasing, the formation of CO and CH4 were hindered, while CO2 and H2 were promoted. For the coal-oil-water slurry, oil promoted CH4 and H2 production but inhibited CO and CO2. Moreover, the variation of the nitrogen-containing pyrolytic gas during pyrolysis was studied for various concentrations of coal-water and coal-oil-water slurries at different temperatures. The relative content of HCN and NH3 gradually increased with the increase of pyrolysis temperature and water content. For coal-oil-water slurry, the waste lubricating oil promoted the formation of HCN and NH3, with the relative content of HCN being much higher than that of NH3. To study the mechanism of nitrogen migration during pyrolysis, Lammps was used to simulate pyrolytic behavior of pyrrole and pyridine under N2 and steam atmospheres. The increase in temperature promoted the decomposition of pyrrole and pyridine, thereby promoting the production of HCN and NH3. Finally, the properties and the combustion reactivities of the chars were analyzed. The water and oil content in the coal-water slurry increased the structural ordering degree of chars but decreased the combustion reactivities.

Numerical Analysis on the Evolution of NH2 in Ammonia/hydrogen Swirling Flames and Detailed Sensitivity Analysis under Elevated Conditions

ABSTRACT Ammonia/hydrogen blends have received some attention toward the development of new technologies focused on gas turbine combustion systems, as doping of hydrogen in ammonia enhances flame speed and stability while decreasing ignition energy. One of the challenges of these blends relies on the appropriate computational modeling of their combustion properties in combination with the complex hydrodynamics inherent to flow control techniques such as swirling flows, which are known to be the main method of flame stabilization in current gas turbines. Moreover, it is well-known that large reaction kinetic models are difficult to employ in these computational analyses, thus increasing the difficulty of obtaining reliable methods for the design of new combustors. Therefore, this research analyses a reduced chemical reaction mechanism, namely Okafor’s mechanism, comparing its performance and accuracy against obtained experiments. Emission measurements and non-intrusive laser techniques (LDA) were employed to validate models running on CHEMKIN-PRO flow reactors and RANS Complex Chemistry. Once validated, the study identified the main contributors and reaction kinetics of NH2 and NO consumption, hence evaluating the process via production rates and sensitivity analysis of various important reactions. The results depicted positive correlation between NH2 formation and heat release, N2, H2O, N2O, NH, NNH, NO, O formation, whereas NH3, N2H3 and NO2 have shown negative correlation. Statistical correlations supported these findings but unfortunately were inconclusive to the impacts of vorticity and turbulence over the production/consumption of amidogen. Sensitivity analysis has shown NH2 radicals and atomic N to be the main contributors of NO formation in the flame zone, although most of the NO formed in the flame zone shown to be consumed at the post-flame zone due to the presence of NHx radicals and atomic N.

A Numerical Prediction of Stabilized Turbulent Partially Premixed Flames Using Ammonia/Hydrogen Mixture

The objective of this work is to computationally assess the performance of a carbon free ammonia-hydrogen mixture when burnt in a gas turbine like combustor. Recently, utilizing ammonia as an alternative carbon-free fuel for future power, industry applications and achieving clean energy attracted enormous interest. Pure ammonia oxidation is facing many challenges such as high NOx emissions, high ignition energy, slow reactivity and lower laminar flame speeds. Therefore, the use of ammonia/hydrogen mixture provides flame stability and increasing flame speed. In this manuscript a numerical study for a new swirl stabilized combustor for oxidizing ammonia/hydrogen mixture. Numerical two dimensional model simulations of a turbulent flame on Reynolds Averaged Navier Stokes (RANS) including a realizable k-e turbulent scheme with the aid of chemistry mechanism were performed under various conditions. Partially premixed combustion model with flame-let concept was selected and radiation effects are also considered. Validation for the predicted results showed a reasonable agreement when validated with the experimental data. The results discuss the influence of changing inlet pressure and equivalence ratio on the stability and the characteristics of unburnt NH3 and NO emissions. Results show that for constant operating conditions such as constant equivalence ratio of 0.8 that increasing hydrogen content resulted in increasing NO emission. Also, for constant ammonia/hydrogen concentrations, NO emissions increases with equivalence ratio then reduced at rich conditions and NH3 emissions are generally low. Equivalence ratio lower than 1.2 will be preferable to reduce the amount of unburnt NH3 formation.

English

The use of low-cost on-site wastewater treatment technologies, including constructed wetlands (CWs), is wide spread. Despite the purported high performance of vertical-horizontal subsurface flow (V-H SSF) hybrid CWs, data on implementation and performance in developing countries is scarce. Here, the design, operation and performance of V-H SSF hybrid CWs for treatment of municipal sewage in an effort to encourage and direct future research and assist technology choice were reviewed. Literature reveals that successful performance of V-H SSF hybrid CWs depends mainly on system design and is independent of mode of feeding. Moreover, performance and final effluent quality is high for biological oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solids (TSS) which are all reduced by over 80%. Despite high removal of ammonium-nitrogen (NH4+-N), concentration in the final effluent remains above desired levels, which is attributed to the design of V-H SSF hybrid CWs based on BOD as a parameter of choice, rather than nitrogen. It was argued that further research on performance of V-H SSF hybrid CWs based on designs that consider both nitrogen in the form of NH4+-N and BOD and assessment under different climatic conditions, is essential prior to mass implementation of this technology in developing countries. &nbsp; Key words: Hybrid constructed wetlands, municipal wastewater, pollutant removal.

The influence of pH and current density for nano-silver electrodeposited in cyanide-free succinimide bath

The effects of pH and current density on cyanide-free succinimide baths were studied in this paper. The effect of pH on the electrochemical structure and electrochemical process were analyzed by electrochemical impedance spectroscopy (EIS). The reversibility of the bath with different pH was characterized by cyclic voltammetry (CV). The results showed that the electrodeposition process was irreversible in different pH baths. The highest polarizability and reversibility were observed at pH9 bath. The reason of highest polarizability at pH9 is due to the hydrolysis of succinimide and formation of NH3. The compositions of baths with different pH were measured by XPS, which confirmed the hydrolysis of succinimide and the singleness of silver ion's valence state. The nucleation process of silver at different deposition potentials that in the range of -0.4–0.7 V was studied by chronoamperometry. The comparison of dimensionless curves with Scharifker and Hills (SH) theoretical model showed that the nucleation of silver in bath was closer to instantaneous nucleation. The microscopic images of early nucleation were captured, which proved that nucleation was discontinuous and might interfere with each other. The nano-silver films were obtained by electrodeposition within the current density ranging from 0.4 to 0.7 A/dm2. The microstructure observed by scanning electron microscope (SEM). The results showed that grain size increased abnormally with the increase of current density and the silver film exhibited the finest grain size was obtained at the current density of 0.4 A/dm2. The phenomenon was caused by the instantaneous nucleation and the interaction between nucleation points.

Photochemistry of Nitrate Ion: Reduction by Formic Acid under UV Irradiation.

Mutual transformations of various nitrogen compounds and their reaction mechanisms have been a subject of great concern to the chemical, ecological and environmental communities. In the paper, the reactions of ion with small organic acids such as formic acid (HCOOH), acetic acid (CH3 COOH) and lactic acid (C3 H6 O3 ) under ultraviolet illumination were investigated systematically. It was found that ion is easily reduced into and NOx and then further into N2 and NH3 (in the form of ) in the process. The carboxyl anion radicals and hydrogen formed by photodecomposition of formic acid are responsible for the rapid photoreduction reaction of nitrate. The initial pH and the nitrate concentration considerably affect the product distribution and nitrate conversion. Based on a preliminary simulation study, we speculated that the photoinduced reaction may effectively proceed in oceans, lakes and rivers because of ever-increasing nitrate and organic emissions. This research is helpful to understand nitrogen cycle mechanism and develop water environmental control technologies.

Electrochemical Nitric Oxide Reduction on Metal Surfaces.

Electrocatalytic denitrification is a promising technology for removing NOx species (NO3- , NO2- and NO). For NOx electroreduction (NOx RR), there is a desire for understanding the catalytic parameters that control the product distribution. Here, we elucidate selectivity and activity of catalyst for NOx RR. At low potential we classify metals by the binding of *NO versus *H. Analogous to classifying CO2 reduction by *CO vs. *H, Cu is able to bind *NO while not binding *H giving rise to a selective NH3 formation. Besides being selective, Cu is active for the reaction found by an activity-volcano. For metals that does not bind NO the reaction stops at NO, similar to CO2 -to-CO. At potential above 0.3 V vs. RHE, we speculate a low barrier for N coupling with NO causing N2 O formation. The work provides a clear strategy for selectivity and aims to inspire future research on NOx RR.

Electrochemical Nitric Oxide Reduction on Metal Surfaces

AbstractElectrocatalytic denitrification is a promising technology for removing NOx species (NO3−, NO2− and NO). For NOx electroreduction (NOxRR), there is a desire for understanding the catalytic parameters that control the product distribution. Here, we elucidate selectivity and activity of catalyst for NOxRR. At low potential we classify metals by the binding of *NO versus *H. Analogous to classifying CO2 reduction by *CO vs. *H, Cu is able to bind *NO while not binding *H giving rise to a selective NH3 formation. Besides being selective, Cu is active for the reaction found by an activity‐volcano. For metals that does not bind NO the reaction stops at NO, similar to CO2‐to‐CO. At potential above 0.3 V vs. RHE, we speculate a low barrier for N coupling with NO causing N2O formation. The work provides a clear strategy for selectivity and aims to inspire future research on NOxRR.