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Electrocatalytic NO reduction reaction offers a sustainable route to achieving environmental protection and NH3 production targets as well. In this work, a class of dealloyed Ti60Cu33Mn7 ribbons with enough nanoparticles for the high-efficient NO reduction reaction to NH3 is fabricated, reaching an excellent Faradaic efficiency of 93.2% at -0.5 V vs reversible hydrogen electrode and a high NH3 synthesis rate of 717.4 μmol·h-1·mgcat.-1 at -0.6 V vs reversible hydrogen electrode. The formed nanoparticles on the surface of the catalyst could facilitate the exposure of active sites and the transportation of various reactive ions and gases. Meanwhile, the Mn content in the TiCuMn ribbons modulates the chemical and physical properties of its surface, such as modifying the electronic structure of the Cu species, optimizing the adsorption energy of N* atoms, decreasing the strength of the NO adsorption, and eliminating the thermodynamic energy barrier, thus improving the NO reduction reaction catalytic performance. Moreover, a Zn-NO battery was fabricated using the catalyst and Zn plates, generating an NH3 yield of 129.1 μmol·h-1·cm-2 while offering a peak power density of 1.45 mW·cm-2. [ABSTRACT FROM AUTHOR]

Size-tunable Cu nanoparticles on porous N -doped hexagonal carbon nanorods was reasonably developed. The optimal Cu 30% @NH exhibits an ultrahigh yield for NH 3 electrosynthesis due to the favorable adsorption for NO 3 –* key reaction species. [Display omitted] Electrocatalytic nitrate reduction (NO 3 RR) technique has emerged as a hotspot in NH 3 production, for its practicability, and a series of advanced electrocatalysts with high activity and robust stability needed to be constructed in today's era. In this work, size-tunable Cu nanoparticles on porous nitrogen-doped hexagonal carbon nanorods (Cu@NHC) were reasonably designed and served for catalyzing NO 3 RR in neutral media. Especially, Cu 30% @NHC demonstrated a remarkable electroactivity for NH 3 production as it showed a suitable grain size with massive catalytic centers and favorable d band structure with faster *NO 3 −-to-*NO 2 − catalytic dynamics. As expected, Cu 30% @NHC (3628.28 µg h−1 mg cat. −1) had a much higher NH 3 yield than those for Cu 20% @NHC (1268.42 µg h−1 mg cat. −1) and Cu 40% @NHC (725.03 µg h−1 mg cat. −1). And those collected NH 3 products indeed derived from NO 3 RR process revealed by 15N isotope-labeling and systemic control tests. Moreover, Cu 30% @NHC was also durable for NO 3 RR bulk electrolysis with minor loss in activity. This work offered an effective modifying tactics to boost NO 3 RR catalysis and could guide the design of other advanced electrocatalysts via size-induced surface engineering. [ABSTRACT FROM AUTHOR]

Electrocatalytic nitrate reduction reaction (NO3RR) offers a unique rationale for green NH3 synthesis, yet the lack of high-efficiency NO3RR catalysts remains a great challenge. In this work, we show that Au nanoclusters anchored on TiO2 nanosheets can efficiently catalyze the conversion of NO3RR-to-NH3 under ambient conditions, achieving a maximal Faradic efficiency of 91%, a peak yield rate of 1923 µg·h−1·mgcat.−1, and high durability over 10 consecutive cycles, all of which are comparable to the recently reported metrics (including transition metal and noble metal-based catalysts) and exceed those of pristine TiO2. Moreover, a galvanic Zn-nitrate battery using the catalyst as the cathode was proposed, which shows a power density of 3.62 mW·cm−2 and a yield rate of 452 µg·h−1·mgcat.−1. Theoretical simulations further indicate that the atomically dispersed Au clusters can promote the adsorption and activation of NO3− species, and reduce the NO3RR-to-NH3 barrier, thus leading to an accelerated cathodic reaction. This work highlights the importance of metal clusters for the NH3 electrosynthesis and nitrate removal. [ABSTRACT FROM AUTHOR]

The electroreduction of nitrate into green ammonia (NO3−‐to‐NH3) in aqueous solution represents a sustainable route applicable to green NH3 electrosynthesis and nitrogen balance. However, the NO3−‐to‐NH3 electroreduction undergoes a complex eight electron (8e−) transfer pathway and results in unsatisfying activity and selectivity. Here, mesostructures engineering is presented as a new and robust design strategy for producing high‐performance multimetallic electrocatalysts that remarkably promote selective NO3−‐to‐NH3 electroreduction. 1D PdCuAg mesoporous nanotubes (MTs) are facilely prepared by a one‐step galvanic replacement‐assisted surfactant‐templating method in an aqueous solution. The electrocatalyst shows remarkable NO3−‐to‐NH3 performance with high NH3 Faradaic efficiency (FENH3) of 95.2%, superior NH3 yield rate of 17.7 mg h−1 mg−1, impressive NH3 energy efficiency of 29.8%, and outstanding stability (50 cycles), all of which are much better than the performance of counterpart electrocatalysts. The promotion of NO3−‐to‐NH3 performance comes from the electron‐rich surface and nanoconfinement microenvironment of mesostructured synergies that enrich nanozyme‐like chemisorption of key intermediates and thus facilitates electroreduction of NO3− into NH3 through an 8e− reaction pathway. Meanwhile,1D PdCuAg MTs are practically explored in a Zn‐NO3− battery, delivering a superior NH3 yield rate of 25.85 µmol h−1 cm−2 and a high FENH3 of 92.4%. [ABSTRACT FROM AUTHOR]

Mesoporous metals have received massive research interests in catalysis and electrocatalysis due to their unique structural features. However, most studies have focused on enhancing activity with much less focus on promoting selectivity. Here, it is reported that the design of bimetallic palladium‐copper (PdCu) alloys at mesoscopic level is a reliable and robust strategy to confine the reaction intermediate and thus boost nitrate reduction reaction (NITRR) electrocatalysis for selective NH3 electrosynthesis. The optimized PdCu mesoporous nanospheres (MSs) disclose a high electrocatalytic NO3−‐to‐NH3 performance with NH3 Faradaic efficiency (FENH3${\rm FE}_{{\rm NH}_{3}}$) of 85%, yield rate of 3058 µg h−1 mg−1, energy efficiency of 31%, and multi‐turn stability. The combination of surface analysis and experimental techniques reveals that the high NO3−‐to‐NH3 performance results from highly penetrated and active mesoporous channels of PdCu MSs that not only kinetically facilitate the adsorption and reactivity of NO3− but also enhance the confinement of key intermediate (NO2−) toward an eight‐electron NITRR pathway for selective NH3 electrosynthesis. More importantly, in accompany with compositional control, trimetallic PdCuRu alloy MSs disclose a superior FENH3${\rm FE}_{{\rm NH}_{3}}$ of 95% and an impressive NH3 yield rate of 8518 µg h−1 mg−1 for selective NO3−‐to‐NH3 electroreduction. [ABSTRACT FROM AUTHOR]

The conversion of NO3−‐to‐NH3 by electrolysis is an appealing approach for wastewater treatment; however, such a process is hindered by the lack of efficient catalysts. Herein, taking the nanoporous Al11Ce3 intermetallic phase as an example, its electrocatalytic NO3− reduction reaction capability is first demonstrated. Benefiting from the unique structural feature, optimized intermediates adsorption and formation behavior, and restrained hydrogen evolution, the catalyst shows a remarkable electrochemical performance with a peak faradaic efficiency of 91 % and yield rate of 4.35 mg h−1 mgcat−1, along with robust activity over 30 h. Further, a Zn−NO3− battery by using Al11Ce3 as the cathode was designed, which gives a maximal power density of 8.5 mW cm−2 and a corresponding NH3 yield rate of 1.97 mg h−1 mgcat−1. [ABSTRACT FROM AUTHOR]

Ru-doped TiO 2 nanoribbon array supported on Ti plate acts as an efficient catalyst for NH 3 synthesis via electrochemical NO 2 − reduction, obtaining an ultra-large NH 3 yield of 1.56 mmol h−1 cm−2 and a super-high Faradaic efficiency of 98.9%. [Display omitted] • Ru doping is shown as an effective strategy to boost NO 2 −-to-NH 3 conversion over TiO 2 nanoribbon array supported on Ti plate. • Ru–TiO 2 /TP achieves an ultra-large NH 3 yield of 1.56 mmol h−1 cm−2 and a super-high Faradaic efficiency of 98.9% with long-term electrolytic durability. • DFT calculations reveal the catalytic mechanism of NO 2 –RR on Ru–TiO 2. Electrochemical reduction of nitrite (NO 2 –) not only removes NO 2 – contaminant but also produces high-added value ammonia (NH 3). This process, however, needs efficient and selective catalysts for NO 2 −-to-NH 3 conversion. In this study, Ruthenium doped titanium dioxide nanoribbon array supported on Ti plate (Ru–TiO 2 /TP) is proposed as an efficient electrocatalyst for the reduction of NO 2 − to NH 3. When operated in 0.1 M NaOH containing NO 2 –, such Ru–TiO 2 /TP achieves an ultra-large NH 3 yield of 1.56 mmol h−1 cm−2 and a super-high Faradaic efficiency of 98.9%, superior to its TiO 2 /TP counterpart (0.46 mmol h−1 cm−2, 74.1%). Furthermore, the reaction mechanism is studied by theoretical calculation. [ABSTRACT FROM AUTHOR]

Ambient electrochemical nitrite (NO2-) reduction is viewed as an effective and sustainable approach for simultaneously removing NO2- and producing ammonia (NH3). However, the complex multi-electron transfer steps involved in the NO2- reduction reaction (NO2-RR) lead to sluggish kinetics and low product selectivity toward NH3, underscoring the need for NH3 synthesis electrocatalysts with high activity and durability. Herein, we report amorphous indium–tin oxide sputtered on a TiO2 nanobelt array on a Ti plate (ITO@TiO2/TP) as a 3D NH3-producing catalyst for the NO2-. In 0.5 ​M LiClO4 with 0.1 ​M NO2-, it shows greatly boosted NO2-RR activity toward NH3 production, with excellent selectivity, achieving a large NH3 yield of 411.3 ​μmol ​h−1 ​cm−2 and a high Faradaic efficiency of 82.6%. It also shows high durability for continuous electrolysis. A Zn‐NO2- battery with ITO@TiO2/TP cathode offers an NH3 yield of 23.1 ​μmol ​h−1 ​cm−2 and a peak power density of 1.22 ​mW ​cm−2.

Ambient NH3 electrosynthesis from NO reduction reaction (NORR) is attractive in replacing the industrial Haber‐Bosch route; however, the competitive hydrogen evolution reaction (HER) in aqueous electrolyte typically induces a limited selectivity and activity toward NH3 production. Herein, hierarchical P‐doped MoS2 nanospheres are developed as the NORR electrocatalyst in an ionic liquid (IL) electrolyte for catalyzing the reduction of NO to NH3 with a maximal Faradaic efficiency of 69 % (−0.6 V vs RHE) and a peak yield rate of 388.3 μg h−1 mgcat.−1 (−0.7 V vs RHE), both of which are comparable to the best‐reported results. Moreover, the catalyst also shows stable NORR activity over 30 h and 6 cycles. Theoretical analyses further reveal that the P dopants in MoS2 facilitate the activation and hydrogenation of NO. Besides, the employment of hydrophobic IL electrolyte also slows down the HER kinetics effectively. [ABSTRACT FROM AUTHOR]

Ambient NH3 electrosynthesis from NO reduction reaction (NORR) is attractive in replacing the industrial Haber‐Bosch route; however, the competitive hydrogen evolution reaction (HER) in aqueous electrolyte typically induces a limited selectivity and activity toward NH3 production. Herein, hierarchical P‐doped MoS2 nanospheres are developed as the NORR electrocatalyst in an ionic liquid (IL) electrolyte for catalyzing the reduction of NO to NH3 with a maximal Faradaic efficiency of 69 % (−0.6 V vs RHE) and a peak yield rate of 388.3 μg h−1 mgcat.−1 (−0.7 V vs RHE), both of which are comparable to the best‐reported results. Moreover, the catalyst also shows stable NORR activity over 30 h and 6 cycles. Theoretical analyses further reveal that the P dopants in MoS2 facilitate the activation and hydrogenation of NO. Besides, the employment of hydrophobic IL electrolyte also slows down the HER kinetics effectively. [ABSTRACT FROM AUTHOR]

An oxygen-deficient NiCo 2 O 4 porous nanowire arrays have been developed as excellent bifunctional electrodes for ethylene glycol oxidation reaction (EGOR) assisted NO 3 RR system. The MEA-based electrolyzer delivers significantly improved cell voltage, high yield and Faradaic efficiency of NH 3 and formate, along with superior catalytic stability. [Display omitted] • Ethylene glycol oxidation reaction (EGOR) assisted NO 3 RR technology is developed. • The NO 3 RR||EGOR electrolyzer obtains a low voltage of 1.63 V at 100 mA cm−2 and superior stability over 120 h. • The high Faradaic efficiency of formate (over 94.2 %) and NH 3 (over 96.3 %) at 1.4 V are realized. • The main active Co-O species and NHO pathway are confirmed by in-situ spectroscopic characterizations. Electrocatalytic nitrate reduction (NO 3 RR) is emerging as promising pathway for ammonia (NH 3) synthesis. The development of NO 3 RR-based coupling systems are vital for the energy-saving electrosynthesis of high-added chemicals, but the efficient bifunctional electrocatalysts are lacking. Herein, we take oxygen-deficient NiCo 2 O 4 (V o -NiCo 2 O 4) porous nanowire as a conceptual example to study its potential application in the co-production of NH 3 and formate by ethylene glycol oxidation reaction (EGOR) assisted NO 3 RR technology. Benefiting from the unique porous structure, abundant oxygen vacancies, active dual metal centers, and the improved reaction kinetics, the V o -NiCo 2 O 4 /NF displays excellent bifunctional performance and can be applied for NO 3 RR||EGOR electrolyzer by the membrane electrode assembly (MEA). Specifically, the electrolyzer achieves a high current density of 100 mA cm−2 a low voltage of 1.53 V and delivers high Faradaic efficiency of formate (over 94.2 %) and NH 3 (over 96.3 %) at 1.4 V, along with superior catalytic stability over 120 h. In-situ characterizations confirm the main active Co-O species and the formation of formate for EGOR, as well as the NHO pathway with the appearance of –NH 2 OH key intermediate for NO 3 RR. Our work offers a promising strategy for co-upcycling production of valuable chemicals. [ABSTRACT FROM AUTHOR]

Ammonia (NH 3 ) synthesis via the nitrate reduction reaction (NO 3 RR) offers a competitive strategy for nitrogen cycling and carbon neutrality; however, this is hindered by the poor NO 3 RR performance under high current density. Herein, it is shown that boron-doped Ti 3 C 2 T x MXene nanosheets can highly efficiently catalyze the conversion of NO 3 RR-to-NH 3 at ambient conditions, showing a maximal NH 3 Faradic efficiency of 91% with a peak yield rate of 26.2 mgh -1  mg cat. -1 , and robust durability over ten consecutive cycles, all of them are comparable to the best-reported results and exceed those of pristine Ti 3 C 2 T x MXene. More importantly, when tested in a flow cell, the designed catalyst delivers a current density of ‒1000 mA cm -2 at a low potential of ‒1.18 V versus the reversible hydrogen electrode and maintains a high NH 3 selectivity over a wide current density range. Besides, a Zn-nitrate battery with the catalyst as the cathode is assembled, which achieves a power density of 5.24 mW cm -2 and a yield rate of 1.15 mgh -1  mg cat. -1 . Theoretical simulations further demonstrate that the boron dopants can optimize the adsorption and activation of NO 3 RR intermediates, and reduce the potential-determining step barrier, thus leading to an enhanced NH 3 selectivity., (© 2024 Wiley‐VCH GmbH.)

Electrochemical upcycling of waste pollutants into high value-added fuels and/or chemicals is recognized as a green and sustainable solution that can address the resource utilization on earth. Despite great efforts, their progress has seriously been hindered by the lack of high-performance electrocatalysts. In this work, bimetallic PdCu mesoporous nanocavities (MCs) are reported as a new bifunctional enzymatic electrocatalyst that realizes concurrent electrocatalytic upcycling of nitrate wastewater and polyethylene terephthalate (PET) plastic waste. Abundant metal mesopores and open nanocavities of PdCu MCs provide the enzymatic confinement of key intermediates for the deeper electroreduction of nitrate and accelerate the transport of reactants/products within/out of electrocatalyst, thus affording high ammonia Faradic efficiency (FE NH3 ) of 96.6% and yield rate of 5.6 mg h -1  mg -1 at the cathode. Meanwhile, PdCu MC nanozymes trigger the selective electrooxidation of PET-derived ethylene glycol (EG) into glycolic acid (GA) and formic acid with high FEs of >90% by a facile regulation of potentials at the anode. Moreover, concurrent electrosynthesis of value-added NH 3 and GA is disclosed in the two-electrode coupling system, further confirming the high efficiency of bifunctional PdCu MC nanozymes in producing value-added fuels and chemicals from waste pollutants in a sustainable manner., (© 2024 Wiley‐VCH GmbH.)

Electrocatalytic NO reduction reaction to generate NH3 under ambient conditions offers an attractive alternative to the energy-extensive Haber–Bosch route; however, the challenge still lies in the development of cost-effective and high-performance electrocatalysts. Herein, nanoporous VN film is first designed as a highly selective and stable electrocatalyst for catalyzing reduction of NO to NH3 with a maximal Faradaic efficiency of 85% and a peak yield rate of 1.05 × 10–7 mol·cm–2·s–1 (corresponding to 5,140.8 μg·h–1·mgcat.–1) at –0.6 V vs. reversible hydrogen electrode in acid medium. Meanwhile, this catalyst maintains an excellent activity with negligible current density and NH3 yield rate decays over 40 h. Moreover, as a proof-of-concept of Zn–NO battery, it delivers a high power density of 2.0 mW·cm–2 and a large NH3 yield rate of 0.22 × 10–7 mol·cm–2·s–1 (corresponding to 1,077.1 μg·h–1·mgcat.–1), both of which are comparable to the best-reported results. Theoretical analyses confirm that the VN surface favors the activation and hydrogenation of NO by suppressing the hydrogen evolution. This work highlights that the electrochemical NO reduction is an eco-friendly and energy-efficient strategy to produce NH3.

[Display omitted] • Nb single atoms on ZrO 2 (Nb 1 -ZrO 2) are explored as an efficient NO 2 RR catalyst. • Nb 1 -ZrO 2 shows an FE NH3 of 95.87 % and NH 3 yield rate of 1588.78 μmol h−1 cm−2. • Nb 1 -Zr dual sites enhance NO 2 – activation and lower the reaction energy barrier. • This work provides a new way to regulate the activity of electrocatalytic NO 2 RR. Electrochemical nitrite-to-ammonia reduction offers a promising avenue for wastewater treatment and sustainable electrosynthesis of NH 3. In this study, we immobilize Nb single atoms on a ZrO 2 substrate (Nb 1 –ZrO 2) as an efficient NO 2 RR catalyst. It is demonstrated that the created Nb 1 -Zr dual sites on Nb 1 -ZrO 2 enhance the adsorption and activation of NO 2 , optimize the adsorption of key·NH 3 intermediate to lower the reaction energy barrier, resulting in an overall enhancement of the NO 2 RR activity. Remarkably, by assembling Nb 1 -ZrO 2 in a flow cell, we achieve the maximum FE NH3 of 95.87 % and NH 3 yield rate of 1588.78 µmol h−1cm−2 at a high current density of 263.59 mA cm−2, as well as the stable operation of 100 h, performing among the best of reported NO 2 RR electrocatalysts. [ABSTRACT FROM AUTHOR]

Ammonia is an essential chemical for producing fertilizers and energy carriers. However, the industrial Haber–Bosch process causes huge CO2 emissions and energy waste. As a promising alternative for Haber‐Bosch process, electrochemical synthesis of ammonia has drawn much attention. Catalysts, as a vital part of electrochemical nitrogen reduction reaction (NRR), have developed rapidly in recent years. Compared to noble‐metal catalysts, noble‐metal‐free catalysts possess a low‐cost advantage. In this review, noble‐metal‐free catalysts, including metal‐based materials, metal organic frameworks (MOFs), MXenes, and metal‐free materials, are summarized. In addition, effective design strategies are discussed, along with the main problems and some potential directions of noble‐metal‐free NRR catalysts. [ABSTRACT FROM AUTHOR]

As a carbon-neutral alternative to the Haber-Bosch process, electrochemical N2 reduction enables environment-friendly NH3 synthesis at ambient conditions but needs active electrocatalysts for the N2 reduction reaction. Here, we report that conductive metal—organic framework Co3(hexahydroxytriphenylene)2 (Co3HHTP2) nanoparticles act as an efficient catalyst for ambient electrochemical N2-to-NH3 fixation. When tested in 0.5 M LiClO4, such Co3HHTP2 achieves a large NH3 yield of 22.14 µg·h−1mg−1cat. with a faradaic efficiency of 3.34% at −0.40 V versus the reversible hydrogen electrode. This catalyst also shows high electrochemical stability and excellent selectivity toward NH3 synthesis. [ABSTRACT FROM AUTHOR]

• NbSe 2 NSA is firstly reported as an electrocatalyst for ambient NRR. • 3D nanostructures of NbSe 2 facilitate mass transport and exposure of active sites. • NbSe 2 NSA can effectively actiate N 2 molecules. As a promising alternative to the Haber–Bosch process for producing NH 3 , the electrocatalytic nitrogen reduction reaction (NRR) in the aqueous electrolyte has attracted much attention. However, the presence of sluggish reaction kinetics and competitive hydrogen evolution could result in poor activity and unsatisfactory selectivity. Herein, self-supported NbSe 2 nanosheet arrays have been prepared and tested as electrocatalysts for NH 3 electrosynthesis with a Faradaic efficiency of 13.9 ± 1.0% at −0.4 V versus the reversible hydrogen electrode (vs RHE) and a yield rate of 89.5 ± 6.0 μg h−1 mg cat. −1 at −0.45 V vs RHE in 0.1 M Na 2 SO 4 under ambient conditions. Moreover, this electrocatalyst showed excellent durability during the 60-h electrolysis (no stable decay of Faradaic efficiencies and NH 3 yield rates). Furthermore, density functional theory calculations disclosed that NbSe 2 can effectively catalyze the dissociation of the adsorbed N 2 molecule and thus promote the NRR process. [ABSTRACT FROM AUTHOR]

Electrochemical N2 reduction offers a promising alternative to the Haber-Bosch process for sustainable NH3 synthesis at ambient conditions, but it needs efficient catalysts for the N2 reduction reaction (NRR). Here, we report that FeOOH quantum dots decorated graphene sheet acts as a superior catalyst toward enhanced electrocatalytic N2 reduction to NH3 under ambient conditions. In 0.1 M LiClO4, this hybrid attains a large NH3 yield rate and a high Faradaic efficiency of 27.3 µg·h−1·mg−1cat. and 14.6% at −0.4 V vs. reversible hydrogen electrode, respectively, rivalling the current efficiency of all Fe-based NRR electrocatalysts in aqueous media. It also shows strong durability during the electrolytic process. [ABSTRACT FROM AUTHOR]

Electrocatalytic nitrite reduction to ammonia (NO 2 RR) presents an efficient approach for both wastewater treatment and powerful ammonia electrosynthesis. However, the activity and selectivity of NO 2 RR are limited by its complex six−electron transfer process and competitive hydrogen evolution. Herein, Mo single atoms anchored on a zirconium dioxide substrate (Mo 1 –ZrO 2) are first explored as a highly selective and active catalyst for the NO 2 RR, exhibiting a maximum NH 3 −Faraday efficiency of 94.83% with a corresponding ammonia yield rate of 346.92 μmol h−1 cm−2 at −0.7 V vs. RHE. Theoretical calculations reveal that the isolated Mo sites can effectively activate nitrite, enhance nitrite−to−ammonia protonation energetics and prohibit competitive hydrogen evolution, thus leading to the remarkably enhanced selectivity and activity of Mo 1 –ZrO 2 for the NO 2 RR. [Display omitted] • Mo single atoms anchored on ZrO 2 substrate (Mo 1 –ZrO 2) are explored as an efficient NO 2 RR catalyst. • Mo 1 –ZrO 2 shows the highest FE NH3 of 94.83% and NH 3 yield rate of 346.92 μmol h−1 cm−2 at −0.7 V vs. RHE. • DFT/MD calculations are adopted to profoundly understand the NO 2 RR mechanism of Mo 1 –ZrO 2. • This work opens up a new avenue to explore high-performance single-atom catalysts towards the NO 2 RR. [ABSTRACT FROM AUTHOR]

Electrocatalytic N2 reduction reaction (NRR) into ammonia (NH3), especially if driven by renewable energy, represents a potentially clean and sustainable strategy for replacing traditional Haber– Bosch process and dealing with climate change effect. However, electrocatalytic NRR process under ambient conditions often suffers from low Faradaic efficiency and high overpotential. Developing newly regulative methods for highly efficient NRR electrocatalysts is of great significance for NH3 synthesis. Here, we propose an interfacial engineering strategy for designing a class of strongly coupled hybrid materials as highly active electrocatalysts for catalytic N2 fixation. X-ray absorption near-edge spectroscopy (XANES) spectra confirm the successful construction of strong bridging bonds (Co–N/S–C) at the interface between CoSx nanoparticles and NS-G (nitrogen- and sulfurdoped reduced graphene). These bridging bonds can accelerate the reaction kinetics by acting as an electron transport channel, enabling electrocatalytic NRR at a low overpotential. As expected, CoS2/NS-G hybrids show superior NRR activity with a high NH3 Faradaic efficiency of 25.9%at −0.05 V versus reversible hydrogen electrode (RHE). Moreover, this strategy is general and can be extended to a series of other strongly coupled metal sulfide hybrids. This work provides an approach to design advanced materials for ammonia production. [ABSTRACT FROM AUTHOR]

Industrial production of NH3 from N2 and H2 significantly relies on Haber–Bosch process, which suffers from high energy consume and CO2 emission. As a sustainable and environmentally-benign alternative process, electrochemical artificial N2 fixation at ambient conditions, however, is highly required efficient electrocatalysts. In this study, we demonstrate that hexagonal boron nitride nanosheet (h-BNNS) is able to electrochemically catalyze N2 to NH3. In acidic solution, h-BNNS catalyst attains a high NH3 formation rate of 22.4 μg·h–1·mg–1cat. and a high Faradic efficiency of 4.7% at–0.75 V vs. reversible hydrogen electrode, with excellent stability and durability. Density functional theory calculations reveal that unsaturated boron at the edge site can activate inert N2 molecule and significantly reduce the energy barrier for NH3 formation. [ABSTRACT FROM AUTHOR]

Co single atoms anchored on MoS 2 (Co 1 /MoS 2) is demonstrated as a highly active and durable catalyst for electrocatalytic nitric oxide reduction to ammonia (NORR), attributed to the critical role of active Co 1 -S 3 moieties to selectively absorb NO and accelerate the hydrogenation energetics. [Display omitted] • Co single atoms anchored on MoS 2 (Co 1 /MoS 2) catalyst is explored for NO electroreduction to NH 3 (NORR). • Co 1 /MoS 2 exhibits a high NH 3 yield of 217.6 μmol h−1 cm−2 and an NH 3 -Faradaic efficiency of 87.7 % at −0.5 V vs RHE. • Theoretical analyses reveal that Co-S 3 moieties can selectively activate NO and accelerate the hydrogenation energetics. • This work demonstrates the great potential of single-atom catalysts toward the efficient NORR for NH 3 electrosynthesis. Electrocatalytic NO reduction to NH 3 (NORR) represents an energy-efficient and eco-friendly route to simultaneously remedy NO pollution and produce valuable NH 3. Herein, we design atomically dispersed Co anchored on MoS 2 (Co 1 /MoS 2) as a highly active and durable NORR catalyst. Detailed characterizations and theoretical calculations unveil the creation of active Co 1 -S 3 moieties on Co 1 /MoS 2 , which can selectively absorb NO molecules and promote the hydrogenation energetics of NORR process. As a result, Co 1 /MoS 2 exhibits an excellent NORR performance with an NH 3 yield of 217.6 μmol h−1 cm−2 and an NH 3 -Faradaic efficiency of 87.7 % at −0.5 V vs RHE, substantially outperforming pristine MoS 2 and most reported NORR catalysts. [ABSTRACT FROM AUTHOR]

Electrocatalytic N 2 reduction reaction (NRR) into ammonia (NH 3 ), especially if driven by renewable energy, represents a potentially clean and sustainable strategy for replacing traditional Haber-Bosch process and dealing with climate change effect. However, electrocatalytic NRR process under ambient conditions often suffers from low Faradaic efficiency and high overpotential. Developing newly regulative methods for highly efficient NRR electrocatalysts is of great significance for NH 3 synthesis. Here, we propose an interfacial engineering strategy for designing a class of strongly coupled hybrid materials as highly active electrocatalysts for catalytic N 2 fixation. X-ray absorption near-edge spectroscopy (XANES) spectra confirm the successful construction of strong bridging bonds (Co-N/S-C) at the interface between CoS x nanoparticles and NS-G (nitrogen- and sulfur-doped reduced graphene). These bridging bonds can accelerate the reaction kinetics by acting as an electron transport channel, enabling electrocatalytic NRR at a low overpotential. As expected, CoS 2 /NS-G hybrids show superior NRR activity with a high NH 3 Faradaic efficiency of 25.9% at -0.05 V versus reversible hydrogen electrode (RHE). Moreover, this strategy is general and can be extended to a series of other strongly coupled metal sulfide hybrids. This work provides an approach to design advanced materials for ammonia production., Competing Interests: The authors declare no conflict of interest. The authors declare no competing financial interests., (Copyright © 2019 the Author(s). Published by PNAS.)