Nitrogen Reduction Reaction Performance Research Articles

Molybdenum carbide nanosheets with iron doping as electrocatalysts for highly efficient ammonia electrosynthesis

The electrochemical reduction of nitrogen to ammonia represents a greener alternative to the Haber-Bosch process, demanding a shift towards low-cost and high-efficiency electrocatalysts. Recent advances in research have demonstrated the potential of molybdenum carbide-based catalysts to have their unique electronic structure and physicochemical properties. This study introduces ultrathin iron-doped molybdenum carbide nanosheets (Fe-MoC) as a novel catalyst for ammonia electrosynthesis. Demonstrating a remarkable ammonia production rate of 16 µg h−1 mg−1 and a Faradaic efficiency (FE) of approximately 13 % at −0.2 V, our synthesized Fe-MoC nanosheets stand out for their superior catalytic activity and selectivity towards nitrogen activation. The indophenol technique was employed to identify the generation of NH3 in our experiments, followed by UV–vis spectrometry for quantitative analysis. Additionally, various characterization techniques, including XRD, Raman, and XPS, were used to analyze the material structure and surface properties. Through comprehensive characterization and electrochemical studies, we reveal the pivotal role of iron doping in enhancing the electrocatalytic performance for nitrogen reduction reaction (NRR), offering insights into the mechanistic pathways facilitated by Fe-MoC. The future development and perspective of Fe-MoC towards high performance are proposed.

Exploring Nitrogen Reduction Reaction Mechanisms with Graphyne-Confined Single-Atom Catalysts: A Computational Study Incorporating Electrode Potential and pH.

This study reconciles discrepancies between practical electrochemical conditions and theoretical density functional theory (DFT) frameworks, evaluating three graphyne-confined single-atom catalysts (Mo-TEB, Mo@GY, and Mo@GDY). Using both constant charge models in vacuum and constant potential models with continuum implicit solvation, we closely mimic real-world electrochemical environments. Our findings highlight the crucial role of explicitly incorporating electrode potential and pH in the constant potential model, providing enhanced insights into the nitrogen reduction reaction (NRR) mechanisms. Notably, the superior NRR performance of Mo-TEB is attributed to the d-band center's proximity to the Fermi level and enhanced magnetic moments at the atomic center. This research advances our understanding of graphyne-confined single-atom catalysts as effective NRR platforms and underscores the significance of the constant potential model for accurate DFT studies of electrochemical reactions.

High-Throughput screening of TM1TM2/N6–1 (TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Mo) as effective electrocatalysts for nitrogen fixation

The electrochemical nitrogen reduction reaction (NRR) is an emerging nitrogen fixation method in recent years. Double-atom catalysts compensate for the disadvantage of single-atom catalysts having only one active site, improving catalytic reaction activity. Herein, using a four-step high-throughput screening strategy with density functional theory (DFT) calculations, 45 homonuclear and heteronuclear catalysts, namely, transition metal dimers anchored on nitrogen-doped graphene (TM1TM2/N6–1, TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Mo), were systematically studied to evaluate their catalytic performance for NRR. Our results showed that 16 catalysts stand out, among them, ScMo/N6–1 has an ultralow limiting potential of -0.09 V and a Faradaic efficiency of 100 %. This work provides a group of promising candidates and a reasonable high-throughput design strategy for NRR catalysts.

Application of Fe3O4@MoS2 & Co@MoS2 for Electrocatalytic Nitrogen Reduction Reaction Under the Magnetic Field

Ammonia, one of the most essential raw ingredient for fertilizers, pharmaceuticals and neutralization. However, the widespread production of ammonia heavily depends on the Haber-Bosch process, which entails substantial use of fossil fuels due to the demanding reaction conditions involving high pressure and temperature. Consequently, finding a sustainable method for synthesizing ammonia becomes crucial in addressing environmental pollution and mitigating energy crises.In order to improve the efficiency of ammonia production, using materials with high catalytic activity is an important factor. Traditional noble metals are recognized as the best catalytic materials. Nevertheless, the high cost and rarity of noble metals make their development and application has haven limited a lot. In recent years, two-dimensional materials attracted the attention of scientists in the field of catalysis. Among them, Molybdenum disulfide has a unique crystal structure and properties. Therefore, we aim to create a heterostructure by doping Co or incorporating Fe3O4 into MoS2, resulting in a material with either paramagnetic or ferromagnetic properties. We intend to observe the electrochemical performance of these materials under an applied magnetic field to further substantiate the influence of the magnetic field on electrocatalytic performance. Eventually, we successfully improved the performance of Nitrogen Reduction Reaction under the magnetic field. In the test of electrochemical performance at -0.04V (vs. RHE), we successfully increased the Faradaic efficiency of Fe3O4@1T-MoS2 from 32.67 to 37.16. Simultaneously, we elevated the Faradaic efficiency of Co@1T-MoS2 from 22% to 35%. From the result, we further confirmed that with the adding of magnetic field our catalyst can reach a better NRR performance. key word: nitrogen reduction reaction, Fe3O4@1T-MoS2, Cobalt-doped 1T phase molybdenum disulfide, magnetic field

Design of Single-Atom Catalysts on C5N2 for Nitrogen Fixation at Ambient Conditions: A First-Principles Study.

Single atom catalysts (SACs) exhibit the flexible coordination structure of the active site and high utilization of active atoms, making them promising candidates for nitrogen reduction reaction (NRR) under ambient conditions. By the aid of first-principles calculations based on DFT, we have systematically explored the NRR catalytic behavior of thirteen 4d- and 5d-transition metal atoms anchored on 2D porous graphite carbon nitride C N . With high selectivity and outstanding activity, Zr, Nb, Mo, Ta, W and Re-doped C N are identified as potential nominees for NRR. Particularly, Mo@C N possesses an impressive low limiting potential of -0.39 V (corresponding to a very low temperature and atmospheric pressure), featuring the potential determining step involving *N-N transitions to *N-NH via the distal path. The catalytic performance of TM@C N can be well characterized by the adsorption strength of intermediate *N H. Moreover, there exists a volcanic relationship between the catalytic property U and the structure descriptor , which validates the robustness and universality of , combined with our previous study. This work sheds light on the design of SACs with eminent NRR performance.

Density Functional Theory Study of Triple Transition Metal Cluster Anchored on the C2N Monolayer for Nitrogen Reduction Reactions.

The electrochemical nitrogen reduction reaction (NRR) is an attractive pathway for producing ammonia under ambient conditions. The development of efficient catalysts for nitrogen fixation in electrochemical NRRs has become increasingly important, but it remains challenging due to the need to address the issues of activity and selectivity. Herein, using density functional theory (DFT), we explore ten kinds of triple transition metal atoms (M3 = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) anchored on the C2N monolayer (M3-C2N) as NRR electrocatalysts. The negative binding energies of M3 clusters on C2N mean that the triple transition metal clusters can be stably anchored on the N6 cavity of the C2N structure. As the first step of the NRR, the adsorption configurations of N2 show that the N2 on M3-C2N catalysts can be stably adsorbed in a side-on mode, except for Zn3-C2N. Moreover, the extended N-N bond length and electronic structure indicate that the N2 molecule has been fully activated on the M3-C2N surface. The results of limiting potential screen out the four M3-C2N catalysts (Co3-C2N, Cr3-C2N, Fe3-C2N, and Ni3-C2N) that have a superior electrochemical NRR performance, and the corresponding values are -0.61 V, -0.67 V, -0.63 V, and -0.66 V, respectively, which are smaller than those on Ru(0001). In addition, the detailed NRR mechanism studied shows that the alternating and enzymatic mechanisms of association pathways on Co3-C2N, Cr3-C2N, Fe3-C2N, and Ni3-C2N are more energetically favorable. In the end, the catalytic selectivity for NRR on M3-C2N is investigated through the performance of a hydrogen evolution reaction (HER) on them. We find that Co3-C2N, Cr3-C2N, Fe3-C2N, and Ni3-C2N catalysts possess a high catalytic activity for NRR and exhibit a strong capability of suppressing the competitive HER. Our findings provide a new strategy for designing NRR catalysts with high catalytic activity and selectivity.

Enhanced nitrogen electroreduction to ammonia activities on Sb2S3 electrocatalyst by sulfur defects coupled with carbon doping

Exploiting effective, robust while cheap catalysts for the nitrogen reduction reaction (NRR) is of great significance in the scalability and renewability of electrochemical NH3 synthesis. Herein, a synergetic strategy of C dopants and S vacancies was employed into Sb2S3 (marked as C-Sb2S3-x) to boost the electrochemical NRR performance. The induced effects of C dopants and S vacancies of Sb2S3 on the physical and electrochemical behaviors were throughly investigated. Experiments verify that, the content of low oxidation state in Sb species are remarkably enhanced after introducing C dopants and S vacancies, this facilitate the enhanced electric conductivity and NRR activities of C-Sb2S3-x, together with the encouraged reaction kinetics. The prepared C-Sb2S3-x delivered an optimized NH3 yield rate of 47.2 μg h−1 mg−1cat. at −0.6 V along with a high Faradaic efficiency value of 6.4 % at −0.5 V in acid, outperforming than those of Sb2S3 and most disclosed sulfid NRR electrocatalysts. Density functional theory calculations validate that, cooperation of C doping and S vacancy could achieve the elevated NH3 yield rate, Faradaic efficiency as well as competitive stability. This approach puts forward an effective strategy for transition metal compounds to be more suitable for efficient electrocatalysis.

Screening and comparison of 18 transition metal atoms doped to modulate the electrocatalytic synthesis of ammonia with multi-S vacancies MoS2: A study of density functional theory

Electrocatalytic nitrogen reduction reaction (NRR) represents a promising approach for the sustainable production of ammonia (NH3). However, current electrocatalysts exhibit limitations in terms of active sites, high reaction potential, and poor reaction selectivity. Consequently, there is a pressing need for the development of NRR electrocatalysts with high activity and selectivity under mild conditions. Among them, defect engineering and transition metal doping are two effective methods to improve the electronic structure of catalysts. In this paper, density functional theory was used to study the activity of electrocatalytic NRR on Molybdenum disulfide (MoS2) surfaces with 1–4 S vacancy numbers (VSx–MoS2, x = 1–4) and transition metal (TM)-doped VS3–MoS2 (TM@VS3–MoS2). Both VSx–MoS2 showed better structural stability, with S vacancy defects altering the electronic structure of the surface. As more Mo atoms were exposed on the surface of the structure, the adsorption of N2 gradually enhanced and the reaction was more inclined to undergo NRR. Further investigation of 18 TM-doped VS3–MoS2 revealed that the doping of Sc, Ti, V, Y, Zr and Nb atoms effectively inhibits the hydrogen precipitation reaction and reduced the energy of NH3 desorption, which contributed to the continuation of the reaction. Therefore, the improvement of MoS2 electrocatalytic NRR performance can be achieved by constructing S vacancies and TM doping to provide a better basis and reference for experimental exploration.

La doped-Fe2(MoO4)3 with the synergistic effect between Fe2+/Fe3+ cycling and oxygen vacancies enhances the electrocatalytic synthesizing NH3

The electrocatalytic nitrogen reduction reaction (NRR) is a crucial process in addressing energy shortages and environmental concerns by synthesizing the NH3. However, the difficulty of N2 activation and fewer NRR active sites limit the application of NRR. Therefore, the NRR performance can be improved by rapid electron transport paths to participate in multi-electron reactions and N2 activation. Doping with transition metal element is a viable strategy to provide electrons and electronic channels in the NRR. This study focuses on the synthesis of Fe2(MoO4)3 (FeMo) and x%La-doped FeMo (x = 3, 5, 7, and 10) using the hydrothermal method. La-doping creates electron transport channels Fe2+-O2−-Fe3+ and oxygen vacancies, achieving an equal molar ratio of Fe2+/Fe3+. This strategy enables the super-exchange in Fe2+-O2−-Fe3+, and then enhances electron transport speed for a rapid hydrogenation reaction. Therefore, the synergistic effect of Fe2+/Fe3+ cycling and oxygen vacancies improves the NRR performance. Notably, 5%La-FeMo demonstrates the superior NRR performance (NH3 yield rate: 29.6 μg h−1 mgcat−1, Faradaic efficiency: 5.8%) at −0.8 V (vs. RHE). This work analyzes the influence of the catalyst electronic environment on the NRR performance based on the effect on different valence states of ions on electron transport.

Screening transition metal and nonmetal atoms co-doped graphyne as efficient single-atom catalysts for nitrogen reduction

Despite the great potential of electrocatalytic nitrogen reduction reaction (NRR) for more sustainable and energy-efficient ammonia (NH3) production, significant challenges remain, including low activity and poor selectivity of currently available catalysts. In this study, we systematically investigate the electrocatalytic NRR performance of 43 types of single-atom catalysts (SACs) constructed by introducing single transition metal (TM) or/and nonmetal (NM) atoms in graphyne (TM-NM-GY) through first-principles calculations. It is found that Mn-, Os-, B-, Ti-B-, V-B-, Cr-B-, Ru-B-, and Os-B-GY exhibit remarkable efficiency for NRR, showcasing overpotentials lower than 0.34 V. Particularly, Os-B-GY stands out by demonstrating ultra-high catalytic activity, selectivity, and stability for NRR as well as good experimental feasibility, with an impressively low overpotential of merely 0.13 V. The co-doping of Os and B allows for adjusting moderately positive charge densities around Os, which enables strong d-2π* coupling between Os and N2. As a result, the N≡N triple bond is remarkably weakened, facilitating the subsequent NRR process. Moreover, benefiting from the cooperative doping of NM and TM, the potential limiting step is changed, which breaks the inherent linear volcanic relationship between the free energy of the critical intermediate N2H* and limiting potential (UL) on the sole TM-doped system, further enhancing the activity and selectivity. We anticipate that the insights gained from this comprehensive and systematic study can offer valuable guidance for the design and synthesis of novel and highly efficient SACs toward NRR.

The dual-transition-metal dichalcogenide monolayers anchored with Mn dimer: Promising electrocatalysts for efficient nitrogen reduction reaction

Due to its great efficiency, the electrocatalytic nitrogen reduction reaction (NRR) presents itself as a viable and eco-friendly substitute for the traditional Haber-Bosch ammonia production process. However, it is still a formidable task to find electrocatalysts with high activity and selectivity. In this study, a series of transition metals (TM = Ti–Ni, Zr–Mo, Ru–Pd, and Hf–Pt) anchored on 1T′-dual-transition-metal dichalcogenides (1T′-d-TMDs) monolayers (TM2@1T′-CrCoS4) were systematically investigated as electrocatalysts for NRR using first-principles calculations based on density functional theory. Based on a thorough examination of selectivity, high activity, and stability, Mn2@1T′-CrCoS4 and Co2@1T′-CrCoS4 demonstrate exceptional NRR performance. With a limiting potential of −0.11 V, Mn2@1T′-CrCoS4 stood out among them in terms of catalytic activity, favoring the enzymatic pathway. Furthermore, ab initio molecular dynamics (AIMD) simulations were used to assess the dynamic stability of Mn2@1T′-CrCoS4 and Co2@1T′-CrCoS4. To determine the source of increased activities, the density of states (DOS), charge density difference, and crystal orbital Hamilton population analysis were used. According to our research, the 1T′-d-TMDS is a viable substrate for the development of effective NRR catalysts and offers a platform for electrocatalyst experimentation.

Computational screening of single-atom catalysts supported on Al12N12 nanocage for nitrogen reduction reaction

The electrochemical nitrogen reduction reaction (NRR) on TM@Al12N12(TM=Sc∼Cu, Mo, Ru∼Pd) nanocages are investigated by density functional theory (DFT) study. TM@Al12N12(TM=Cr, Co, Ni, Ru, Mo, Rh) are evaluated as potential candidate using N2 adsorption (ΔG(*N2)), protonation reactions in first step (ΔG(*N2-*NNH)) and final step (ΔG(*NH2-*NH3)). Among all the screened deposition systems, the NRR performance shows an increase over the pure Al12N12 nanocage and the first hydrogenation step (*N2-*NNH) is the potential determining step. The electronic effect and charge transfer of the system are analyzed by the density of states (DOS) and natural bond orbital (NBO) charge. The electron density difference and the frontier orbitals analysis reveal that the screened deposition nanocages exhibit a significantly improved activation of N2 compared to the pure Al12N12 nanocage. Especially, the Ru@Al12N12 has excellent reactivity for NRR with the limiting potential of −0.80 V via distal pathway.

Integrating bimetallic borides with g-C3N4 containing cyanamide defects for efficient photocatalytic nitrogen fixation

The sustainable generation of ammonia by photocatalytic nitrogen fixation under mild conditions is fascinating compared to conventional industrial processes. Nevertheless, owing to the low charge transfer efficiency, the insufficient light absorption capacity and limited active sites of the photocatalyst cause the difficult adsorption and activation of N2 molecules, thereby resulting in a low photocatalytic conversion efficiency. Herein, a novel bimetallic CoMoB nanosheets (CoMoB) co-catalyst modified carbon nitride with dual moiety defects (CN-TH3/3) Schottky junction photocatalyst is designed for photocatalytic nitrogen reduction reaction (NRR). The photocatalytic nitrogen reduction rate of the optimized CoMoB/CN-TH3/3 photocatalyst is 4.81 mM·g−1·h−1, which is 6.2 and 2.2 times higher than carbon nitride (CN) (0.78 mM·g−1·h−1) and CN-TH3/3 (2.21 mM·g−1·h−1), respectively. The excellent photocatalytic NRR performance is ascribed not only to the introduction of dual moiety defects (cyano and cyanamide groups) that extends the visible light absorption range and promotes exciton polarization dissociation, but also to the formation of interfacial electric field between CoMoB and CN-TH3/3, which effectively facilitates the interfacial charge transfer. Thus, the synergistic interaction between CN-TH3/3 and CoMoB further increases the electron numble of CoMoB active sites, which effectively strengthens the adsorption and activation of N2 and weakens the NN triple bond, thereby enhancing the photocatalytic NRR activity. This work highlights the introduced dual moiety defects and bimetallic CoMoB co-catalyst to synergistically enhance the photocatalytic nitrogen reduction performance.

Iron Monomers or Trimers on Nitrogen-Doped Carbon: Which Is Better for the Electrocatalytic Nitrogen Reduction Reaction?

The electrocatalytic nitrogen reduction reaction (NRR) presents an alternative method for the Haber-Bosch process, and single-atom catalysts (SACs) to achieve efficient NRR have attracted considerable attention in the past decades. However, whether SACs are more suitable for NRR compared to atomic-cluster catalysts (ACCs) remains to be studied. Herein, we have successfully synthesized both the Fe monomers (Fe1) and trimers (Fe3) on nitrogen-doped carbon catalysts. Both the experiments and DFT calculations indicate that compared to the end-on adsorption of N2 on Fe1 catalysts, N2 activation is enhanced via the side-on adsorption on Fe3 catalysts, and the reaction follows the enzymatic pathway with a reduced free energy barrier for NRR. As a result, the Fe3 catalysts achieved better NRR performance (NH3 yield rate of 27.89 μg h-1 mg-1cat. and Faradaic efficiency of 45.13%) than Fe1 catalysts (10.98 μg h-1 mg-1cat. and 20.98%). Therefore, our research presents guidance to prepare more efficient NRR catalysts.

Regulating Interfacial Microenvironment in Aqueous Electrolyte via a N2 Filtering Membrane for Efficient Electrochemical Ammonia Synthesis.

Electrochemical synthesis of ammonia (NH3) in aqueous electrolyte has long been suffered from poor nitrogen (N2) supply owing to its low solubility and sluggish diffusion kinetics. Therefore, creating a N2 rich microenvironment around catalyst surface may potentially improve the efficiency of nitrogen reduction reaction (NRR). Herein, a delicately designed N2 filtering membrane consisted of polydimethylsiloxane is covered on catalyst surface via superspreading. Because this membrane let the dissolved N2 molecules be accessible to the catalyst but block excess water, the designed N2 rich microenvironment over catalyst leads to an optimized Faradaic efficiency of 39.4% and an NH3 yield rate of 109.2µgh-1mg-1, which is superior to those of the most report metal-based catalysts for electrochemical NRR. This study offers alternative strategy for enhancing NRR performance.

Synergistic Al−Al Dual‐Atomic Site for Efficient Artificial Nitrogen Fixation

AbstractSynthesis of ammonia by electrochemical nitrogen reduction reaction (NRR) is a promising alternative to the Haber–Bosch process. However, it is commonly obstructed by the high activation energy. Here, we report the design and synthesis of an Al−Al bonded dual atomic catalyst stabilized within an amorphous nitrogen‐doped porous carbon matrix (Al2NC) with high NRR performance. The dual atomic Al2‐sites act synergistically to catalyze the complex multiple steps of NRR through adsorption and activation, enhancing the proton‐coupled electron transfer. This Al2NC catalyst exhibits a high Faradaic efficiency of 16.56±0.3 % with a yield rate of 29.22±1.2 μg h−1 mgcat−1. The dual atomic Al2NC catalyst shows long‐term repeatable, and stable NRR performance. This work presents an insight into the identification of synergistic dual atomic catalytic site and mechanistic pathway for the electrochemical conversion of N2 to NH3.

Synergistic Al-Al Dual-Atomic Site for Efficient Artificial Nitrogen Fixation.

Synthesis of ammonia by electrochemical nitrogen reduction reaction (NRR) is a promising alternative to the Haber-Bosch process. However, it is commonly obstructed by the high activation energy. Here, we report the design and synthesis of an Al-Al bonded dual atomic catalyst stabilized within an amorphous nitrogen-doped porous carbon matrix (Al2NC) with high NRR performance. The dual atomic Al2-sites act synergistically to catalyze the complex multiple steps of NRR through adsorption and activation, enhancing the proton-coupled electron transfer. This Al2NC catalyst exhibits a high Faradaic efficiency of 16.56±0.3 % with a yield rate of 29.22±1.2 μg h-1 mgcat -1. The dual atomic Al2NC catalyst shows long-term repeatable, and stable NRR performance. This work presents an insight into the identification of synergistic dual atomic catalytic site and mechanistic pathway for the electrochemical conversion of N2 to NH3.

The intermediate valence state Mo5+ in Fe doping La2(MoO4)3 boosting electrochemical nitrogen reduction

NH3 is considered as an ideal fuel for fuel cells to achieve zero carbon emissions due to its high energy density (at liquefaction) and carbon-free properties. The zero-carbon clean electrocatalytic nitrogen reduction reaction (NRR) is one of the alternative routes for NH3 synthesis. The efficiency of NRR is restricted by the high stability of N N and the slow reaction rate. In this study, La2(MoO4)3 (LaMo), and x%Fe doping-LaMo (x = 3, 5, 7, and 10) are synthesized via a hydrothermal method. The strong electron-donating ability of Fe converts a part of Mo6+ to Mo5+ and Mo4+ improving the electronic environment. The presence of Mo5+, an intermediate valence state, facilitates the oxidation and reduction reactions and establishes rapid electron transport channels. The electron transport of Mo6+↔e−Mo5+ is easier than Mo6+↔2e−Mo4+. Furthermore, the Mo5+ activates N2 and enhances N2 adsorption, boosting the NRR performance. Importantly, the content of Mo5+ exhibits a positive correlation with NH3 yield rate (R2 = 0.89), and Faradaic efficiency (FE, R2 = 0.95). Consequently, the 5%Fe–LaMo exhibits the highest Mo5+ percentage (75.9 %) and NRR performance (NH3 yield rate:30.4 μg h−1 mgcat−1, FE: 3.6 %). Thus, this study proposes a method to enhance the NRR performance by element doping with strong electron-donating ability to regulate the Mo5+ percentage.

Enhancing Nitrogen Reduction Reaction through Formation of 2D/2D Hybrid Heterostructures of MoS2@rGO.

Given the challenging task of constructing an efficient nitrogen reduction reaction (NRR) electrocatalyst with enhanced ambient condition performance, properties such as high specific surface area, fast electron transfer, and design of the catalyst surface constitute a group of key factors to be taken into consideration to guarantee outstanding catalytic performance and durability. Thereof, this work investigates the contribution of the 2D/2D heterojunction interface between MoS2 and reduced graphene oxide (rGO) on the electrocatalytic synthesis of NH3 in an alkaline media. The results revealed remarkable NRR performance on the MoS2@rGO 2D/2D hybrid electrocatalyst, characterized by a high NRR sensitivity (faradaic efficiency) of 34.7% with an NH3 yield rate of 3.98 ± 0.19 mg h-1 cm-2 at an overpotential of -0.3 V vs RHE in 0.1 M KOH solution. The hybrid electrocatalysts also exhibited selectivity for NH3 synthesis against the production of the hydrazine (N2H4) byproduct, hindrance of the competitive hydrogen evolution reaction (HER), and good durability over an operation period of 8 h. In hindsight, the study presented a low-cost and highly efficient catalyst design for achieving enhanced ammonia synthesis in alkaline media via the formation of defect-rich ultrathin MoS2@rGO nanostructures, consisting predominantly of an HER-hindering hexagonal 2H-MoS2 phase.

Tuning electronic environment of B sites in boron carbonitride nanoribbon boosts catalytic activity of reducing N2 to NH3

The electrocatalytic nitrogen reduction reaction (NRR) to synthesize ammonia is an important and challenging task in chemistry, where low-cost, highly active non-metallic catalysts such as boron carbonitride (BCN) are still highly desired. Tuning the electronic environment of the active site B is an effective approach to improve the NRR performance of BCNs. However, the study on the mechanism of this effect has been seriously neglected. The diversity and controllability in atomic arrangements of BCN make it suitable for studying the relationship between the local chemical environment of boron and the catalytic properties. To this end, we design four kinds of BCN materials named as homogeneous BCN nanoribbon and BCN nanosheet enriched with B − C active sites and localized phase-separated BCN nanoribbon and BCN nanosheet rich in B − N active sites, and theoretically screen the homogeneous type BCN nanoribbons that have better NRR performances. Meanwhile, we experimentally demonstrate that the optimized charge redistribution of B atoms in BCN skeleton by tuning the electronic environment makes the B − C sites being the effective centers in NRR, and arising the excellent NH3 productivity of 63.02 μg h−1 mg − 1 cat with a highest Faraday efficiency of 32.28 %.