Accelerating Oxygen Electrocatalysis Kinetics on Metal-Organic Frameworks via Bond Length Optimization.

Metal-organic frameworks (MOFs) have been developed as an ideal platform for exploration of the relationship between intrinsic structure and catalytic activity, but the limited catalytic activity and stability has hampered their practical use in water splitting. Herein, we develop a bond length adjustment strategy for optimizing naphthalene-based MOFs that synthesized by acid etching Co-naphthalenedicarboxylic acid-based MOFs (donated as AE-CoNDA) to serve as efficient catalyst for water splitting. AE-CoNDA exhibits a low overpotential of 260 mV to reach 10 mA cm-2 and a small Tafel slope of 62 mV dec-1 with excellent stability over 100 h. After integrated AE-CoNDA onto BiVO4, photocurrent density of 4.3 mA cm-2 is achieved at 1.23 V. Experimental investigations demonstrate that the stretched Co-O bond length was found to optimize the orbitals hybridization of Co 3d and O 2p, which accounts for the fast kinetics and high activity. Theoretical calculations reveal that the stretched Co-O bond length strengthens the adsorption of oxygen-contained intermediates at the Co active sites for highly efficient water splitting.

Electron Redistribution of Ru Site on MoO2@NiMoO4 Support for Efficient Ampere-Level Current Density Electrolysis of Alkaline Seawater.

Seawater electrolysis is a promising but challenging strategy to generate carbon-neutral hydrogen. A grand challenge for hydrogen evolution reaction (HER) from alkaline seawater electrolysis is the development of efficient and stable electrocatalysts to overcome the limitation of sluggish kinetics. Here, a 3D nanorod hybrid catalyst is reported, which comprises heterostructure MoO2@NiMoO4 supported Ru nanoparticles (Ru/ MoO2@NiMoO4) with a size of ≈5 nm. Benefitting from the effect of strongly coupled interaction, Ru/MoO2@NiMoO4 catalyst exhibits a remarkable alkaline seawater hydrogen evolution performance, featured by a low overpotential of 184 mV at a current density of 1.0 A cm-2, superior to commercial Pt/C (338 mV). Experimental observations demonstrate that the heterostructure MoO2@NiMoO4 as an electron-accepting support makes the electron transfer from the Ru nanoparticles to MoO2, and thereby implements the electron redistribution of Ru site. Mechanistic analysis elucidates that the electron redistribution of active Ru site enhances the ability of hydrogen desorption, thereby promoting alkaline seawater HER kinetics and finally leading to a satisfactory catalysis performance at ampere-level current density of alkaline seawater electrolysis.

Establishing CRISPRi for Programmable Gene Repression and Genome Evolution in Cupriavidus necator.

Cupriavidus necator H16 is a "Knallgas" bacterium with the ability to utilize various carbon sources and has been employed as a versatile microbial cell factory to produce a wide range of value-added compounds. However, limited genome engineering, especially gene regulation methods, has constrained its full potential as a microbial production platform. The advent of CRISPR/Cas9 technology has shown promise in addressing this limitation. Here, we developed an optimized CRISPR interference (CRISPRi) system for gene repression in C. necator by expressing a codon-optimized deactivated Cas9 (dCas9) and appropriate single guide RNAs (sgRNAs). CRISPRi was proven to be a programmable and controllable tool and could successfully repress both exogenous and endogenous genes. As a case study, we decreased the accumulation of polyhydroxyalkanoate (PHB) via CRISPRi and rewired the carbon fluxes to the synthesis of lycopene. Additionally, by disturbing the expression of DNA mismatch repair gene mutS with CRISPRi, we established CRISPRi-Mutator for genome evolution, rapidly generating mutant strains with enhanced hydrogen peroxide tolerance and robustness in microbial electrosynthesis (MES) system. Our work provides an efficient CRISPRi toolkit for advanced genetic manipulation and optimization of C. necator cell factories for diverse biotechnology applications.

The role of reactive phosphate species in the abatement of micropollutants by activated peroxymonosulfate in the treatment of phosphate-rich wastewater.

This study investigated the mechanisms of forming reactive species to degrade micropollutants through the activation of peroxymonosulfate (PMS) by phosphate, a prevalent ion in wastewater. Considering the density functional theory results, the formation of hydrogen bonds between phosphate and PMS molecules might be the crucial step in the overall reactions, which prefers producing ⋅OH and reactive phosphate species (RPS, namely H2PO4⋅, HPO4⋅-, and PO4⋅2-) to yielding SO4⋅-. Besides, in the phosphate (5 mM)/PMS system at pH = 8, HPO4⋅- was modeled to be the dominant radical with a steady-state concentration of 3.6 × 10-12 M, which was 666 and 773 times higher than those of ⋅OH and SO4⋅-. The contributions of 1O2, ⋅OH, SO4⋅-, and RPS to the micropollutant decomposition in phosphate/PMS were studied, and RPS were found to be selective for micropollutants with electron-donating moieties (such as phenolic and aniline groups). Additionally, the degradation pathways of bisphenol A, diclofenac, ibuprofen, and atrazine in phosphate/PMS were proposed according to the detected transformation products. Cytotoxicity analysis was carried out to evaluate the potential environmental impacts resulting from the degradation of micropollutants by phosphate/PMS. This study confirmed the significance of RPS for micropollutant degradation during PMS-based treatment in phosphate-rich scenarios.

Single-atom Iron Catalyst with Biomimetic Active Center to Accelerate Proton Spillover for Medical-level Electrosynthesis of H2 O2 Disinfectant.

Electrosynthesis of H2 O2 has great potential for directly converting O2 into disinfectant, yet it is still a big challenge to develop effective electrocatalysts for medical-level H2 O2 production. Herein, we report the design and fabrication of electrocatalysts with biomimetic active centers, consisting of single atomic iron asymmetrically coordinated with both nitrogen and sulfur, dispersed on hierarchically porous carbon (FeSA -NS/C). The newly-developed FeSA -NS/C catalyst exhibited a high catalytic activity and selectivity for oxygen reduction to produce H2 O2 at a high current of 100 mA cm-2 with a record high H2 O2 selectivity of 90 %. An accumulated H2 O2 concentration of 5.8 wt.% is obtained for the electrocatalysis process, which is sufficient for medical disinfection. Combined theoretical calculations and experimental characterizations verified the rationally-designed catalytic active center with the atomic Fe site stabilized by three-coordinated nitrogen atoms and one-sulfur atom (Fe-N3 S-C). It was further found that the replacement of one N atom with S atom in the classical Fe-N4 -C active center could induce an asymmetric charge distribution over N atoms surrounding the Fe reactive center to accelerate proton spillover for a rapid formation of the OOH* intermediate, thus speeding up the whole reaction kinetics of oxygen reduction for H2 O2 electrosynthesis.

Spin-State Modulation on Metal-Organic Frameworks for Electrocatalytic Oxygen Evolution.

Electrochemical oxygen evolution reaction (OER) kinetics are heavily correlated with hybridization of the transition metal d-orbital and oxygen intermediate p-orbital, which dictates the barriers of intermediate adsorption/desorption on the active sites of catalysts. Herein, a strategy is developed involving strain engineering and coordination regulation to enhance the hybridization of Ni 3d and O 2p orbitals, and the as-synthesized Ni-2,6-naphthalenedicarboxylic acid metal-organic framework (DD-Ni-NDA) nanosheets deliver a low OER overpotential of 260 mV to reach 10 mA cm-2 . By integrating an alkaline anion exchange membrane electrolyzer and Pt/C electrode, 200 and 500 mA cm-2 current densities are reached with cell voltages of 1.6 and 2.1 V, respectively. When loaded on a BiVO4 photoanode, the nanosheet enables highly active solar-driven water oxygen. Structural characterizations together with theoretical calculations reveal that the spin state of the centre Ni atoms is regulated by the tensile strain and unsaturated coordination defects in DD-Ni-NDA, and such spin regulation facilitates spin-dependent charge transfer of the OER. Molecular orbital hybridization analysis reveals the mechanism of OH* and OOH* adsorption energy regulation by changes in the DD-Ni-NDA spin state, which provides a deeper understanding of the electronic structure design of catalysts for the OER.

Designs of Tandem Catalysts and Cascade Catalytic Systems for CO2 Upgrading.

Upgrading CO2 into multi-carbon (C2+) compounds through the CO2 reduction reaction (CO2 RR) offers a practical approach to mitigate atmospheric CO2 while simultaneously producing high value chemicals. The reaction pathways for C2+ production involve multi-step proton-coupled electron transfer (PCET) and C-C coupling processes. By increasing the surface coverage of adsorbed protons (*Had ) and *CO intermediates, the reaction kinetics of PCET and C-C coupling can be accelerated, thereby promoting C2+ production. However, *Had and *CO are competitively adsorbed intermediates on monocomponent catalysts, making it difficult to break the linear scaling relationship between the adsorption energies of the *Had /*CO intermediate. Recently, tandem catalysts consisting of multicomponents have been developed to improve the surface coverage of *Had or *CO by enhancing water dissociation or CO2 -to-CO production on auxiliary sites. In this context, we provide a comprehensive overview of the design principles of tandem catalysts based on reaction pathways for C2+ products. Moreover, the development of cascade CO2 RR catalytic systems that integrate CO2 RR with downstream catalysis has expanded the range of potential CO2 upgrading products. Therefore, we also discuss recent advancements in cascade CO2 RR catalytic systems, highlighting the challenges and perspectives in these systems.

Single-Piece Membrane Supercapacitor with Exceptional Areal/Volumetric Capacitance via Double-Face Print of Electrode/Electrolyte Active Ink.

Single-piece flexible supercapacitors (FSCs) have light and ultrathin superiorities, thereby having great potential in portable/wearable electronics. However, all the available single-piece FSCs are fabricated by in situ growth routes, which are incompatible with large-scale technology. This work designs a carboxymethyl cellulose/phytic acid/polyaniline ink, incorporating electrode with electrolyte active compositions. Based on the electrode/electrolyte active ink, a double-face print technique on mixed cellulose ester and nylon membranes to fabricate single-piece membrane-FSCs, where both sides of membranes can be utilized well, is proposed. Consequently, one FSC is measured to be only ≈0.785 cm2 in area, ≈0.021 g in weight, and ≈200 µm in thickness, while it has exceptional areal and volumetric capacitances up to 757 mF cm-2 and 37.8 F cm-3 , respectively, based on the entire device. It also exhibits high flexibility with a capacitance retention of 98% after 2000 bend cycles from 0° to 180°. The state-of-the-art FSCs are expected to have exciting prospects in portable/wearable electronics, smart reading, and flexible displays. The preparation strategy renders the massive production of large-area and mini-size arrayed FSCs, and also the "do-it-yourself" or homemade preparation, which adds more interest and designability for general users.

Electrochemical C-N coupling of CO2 and nitrogenous small molecules for the electrosynthesis of organonitrogen compounds.

Electrochemical C-N coupling reactions based on abundant small molecules (such as CO2 and N2) have attracted increasing attention as a new "green synthetic strategy" for the synthesis of organonitrogen compounds, which have been widely used in organic synthesis, materials chemistry, and biochemistry. The traditional technology employed for the synthesis of organonitrogen compounds containing C-N bonds often requires the addition of metal reagents or oxidants under harsh conditions with high energy consumption and environmental concerns. By contrast, electrosynthesis avoids the use of other reducing agents or oxidants by utilizing "electrons", which are the cleanest "reagent" and can reduce the generation of by-products, consistent with the atomic economy and green chemistry. In this study, we present a comprehensive review on the electrosynthesis of high value-added organonitrogens from the abundant CO2 and nitrogenous small molecules (N2, NO, NO2-, NO3-, NH3, etc.) via the C-N coupling reaction. The associated fundamental concepts, theoretical models, emerging electrocatalysts, and value-added target products, together with the current challenges and future opportunities are discussed. This critical review will greatly increase the understanding of electrochemical C-N coupling reactions, and thus attract research interest in the fixation of carbon and nitrogen.

Accelerated Transfer and Spillover of Carbon Monoxide through Tandem Catalysis for Kinetics-boosted Ethylene Electrosynthesis.

Cu-based catalysts have been widely applied in electroreduction of carbon dioxide (CO2 ER) to produce multicarbon (C2+ ) feedstocks (e.g., C2 H4 ). However, the high energy barriers for CO2 activation on the Cu surface is a challenge for a high catalytic efficiency and product selectivity. Herein, we developed an in situ *CO generation and spillover strategy by engineering single Ni atoms on a pyridinic N-enriched carbon support with a sodalite (SOD) topology (Ni-SOD/NC) that acted as a donor to feed adjacent Cu nanoparticles (NPs) with *CO intermediate. As a result, a high C2 H4 selectivity of 62.5 % and an industrial-level current density of 160 mA cm-2 at a low potential of -0.72 V were achieved. Our studies revealed that the isolated NiN3 active sites with adjacent pyridinic N species facilitated the *CO desorption and the massive *CO intermediate released from Ni-SOD/NC then overflowed to Cu NPs surface to enrich the *CO coverage for improving the selectivity of CO2 ER to C2 H4 .

A rare case of bladder cancer that metastasized to brain, heart, and lung lymph nodes benefited from immunotherapy.

Bladder cancer is a common malignant tumor of the genitourinary system, with the primary cause of death being metastasis. The most common metastatic sites are the lymph nodes, liver, lung, bone, peritoneum, pleura, kidney, adrenal gland, and the intestine. Brain and heart metastases are rare. In this report, we describe a patient who had pulmonary lymph node metastases more than a year after being diagnosed with bladder cancer, followed by brain and cardiac metastases more than two years later. Following the failure of standard first-line chemotherapy, the patient accepted 6 cycles of tislelizumab immunotherapy. The re-examination revealed that the bilateral frontal brain metastases had vanished, the right temporal lobe metastases had been greatly decreased, the neurological symptoms had been alleviated, and the cardiac metastases had disappeared. This is a rare clinical case with encouraging effects of tislelizumab and can serve as a model for the treatment of similar patients.

Exceptional catalytic activity of oxygen evolution reaction via two-dimensional graphene multilayer confined metal-organic frameworks.

Oxygen evolution reaction (OER) plays a key role in many renewable energy technologies such as water splitting and metal-air batteries. Metal-organic frameworks (MOFs) are appealing to design efficient OER electrocatalysts, however, their intrinsic poor conductivity strongly hinders the activity. Here, we show a strategy to boost the OER activity of poor-conductive MOFs by confining them between graphene multilayers. The resultant NiFe-MOF//G gives a record-low overpotential of 106 mV to reach 10 mA cm-2 and retains the activity over 150 h, which is in significant contrast to 399 mV of the pristine NiFe-MOF. We use X-ray absorption spectroscopy (XAS) and computations to demonstrate that the nanoconfinement from graphene multilayers not only forms highly reactive NiO6-FeO5 distorted octahedral species in MOF structure but also lowers limiting potential for water oxidation reaction. We also demonstrate that the strategy is applicable to other MOFs of different structures to largely enhance their electrocatalytic activities.

Accelerated water activation and stabilized metal-organic framework via constructing triangular active-regions for ampere-level current density hydrogen production.

Two-dimensional metal-organic frameworks (MOFs) have been explored as effective electrocatalysts for hydrogen evolution reaction (HER). However, the sluggish water activation kinetics and structural instability under ultrahigh-current density hinder their large-scale industrial applications. Herein, we develop a universal ligand regulation strategy to build well-aligned Ni-benzenedicarboxylic acid (BDC)-based MOF nanosheet arrays with S introducing (S-NiBDC). Benefiting from the closer p-band center to the Fermi level with strong electron transferability, S-NiBDC array exhibits a low overpotential of 310 mV to attain 1.0 A cm-2 with high stability in alkaline electrolyte. We speculate the newly-constructed triangular "Ni2-S1" motif as the improved HER active region based on detailed mechanism analysis and structural characterization, and the enhanced covalency of Ni-O bonds by S introducing stabilizes S-NiBDC structure. Experimental observations and theoretical calculations elucidate that such Ni sites in "Ni2-S1" center distinctly accelerate the water activation kinetics, while the S site readily captures the H atom as the optimal HER active site, boosting the whole HER activity.

Metal-Organic Frameworks with Assembled Bifunctional Microreactor for Charge Modulation and Strain Generation toward Enhanced Oxygen Electrocatalysis.

Two-dimensional metal-organic frameworks (MOFs) have served as favorable prototypes for electrocatalytic oxygen evolution reaction (OER). Despite promising catalytic activity, their OER reaction kinetics are still limited by the sluggish four-electron transfer process. Herein, we develop a ferrocene carboxylic acid (FcCA) partially substituted cobalt-terephthalic acid (CoBDC) catalyst with a bifunctional microreactor composed of two species of Co active sites and ligand FcCA (CoBDC FcCA). Benefiting from the ultrathin nanosheet structure, CoBDC FcCA catalyst exhibits an excellent OER performance with a low overpotential of 280 mV to reach 10 mA cm-2 and a small Tafel slope of 53 mV dec-1. Structure characterization together with theoretical calculations directly unravel the coordination for two species of Co active moieties with FcCA forming a microreactor of tensile strain, leading to a conversion of the Co spin from a high spin state (t2g5eg2) to an intermediate spin state (t2g6eg1) to regulate antibonding states of Co 3d and O 2p orbital. In situ spectroscopic measurements for mechanistic understanding reveal that this CoBDC FcCA catalyst possesses an optimal OH* adsorption energy for propitious formation of O-O bonds in the OOH* intermediate, thus effectively decreasing the thermodynamic Gibbs free energy of the rate-determining step (O* → OOH*) to accelerate reaction kinetics for the whole OER process. When loaded on an integrated BiVO4 photoanode as a cocatalyst, CoBDC FcCA enables highly active solar-driven oxygen production from water splitting.

The inhibitory effects and underlying mechanism of high ammonia stress on sulfide-driven denitrification process.

Sulfide-driven denitrification (SD) process has been widely studied for treating wastewater containing sulfate and ammonia in recent years. But influence of high ammonia stress on the SD process and microbial community remained unclear. In this work, a series of tests were conducted to investigate effects of different ammonia stress (200-3000 mg-total ammonia nitrogen (TAN)/L) on denitrification efficiency, byproduct accumulation and microbial community of the SD process. According to our results, the SD process was severely inhibited, and 32.67 ± 5.15 mg/L NO2--N was accumulated when ammonia stress reached 3000 mg TAN/L. But the inhibited SD process could recover in about 40 days when ammonia stress was decreased to 200 mg TAN/L. After analyzing the microbial community, Thiobacillus sp. (Thiobacillus sp. 65-29, Thiobacillus sp. SCN 64-317, Thiobacillus sp. 63-78 and Thiobacillus denitrificans) was confirmed as dominant bacteria responsible for the SD process. Further, expression of narG, napA, nirK and nirS were inhibited under high ammonia stress, thus making the SD process stuck in NO3- and NO2- reduction step. This study reveals the inhibitory effects of high ammonia stress on the SD process and its possible underlying mechanism with discussion in gene level.

Local Spin-State Tuning of Iron Single-Atom Electrocatalyst by S-Coordinated Doping for Kinetics-Boosted Ammonia Synthesis.

The electrochemical nitrogen reduction reaction (e-NRR) is envisaged as alternative technique to the Haber-Bosch process for NH3 synthesis. However, how to develop highly active e-NRR catalysts faces daunting challenges. Herein, a viable strategy to manipulate local spin state of isolated iron sites through S-coordinated doping (FeSA -NSC) is reported. Incorporation of S in the coordination of FeSA -NSC can induce the transition of spin-polarization configuration with the formation of a medium-spin-state of Fe (t2g 6 eg 1), which is beneficial for facilitating eg electrons to penetrate the antibonding π-orbital of nitrogen. As a consequence, a record-high current density up to 10 mA cm-2 can be achieved, together with a high NH3 selectivity of ≈10% in a flow cell reactor. Both experimental and theoretical analyses indicate that the monovalent Fe(I) atomic center in the FeSA -NSC after the S doping accelerates the N2 activation and protonation in the rate-determining step of *N2 to *NNH.

Pyrogenic carbon facilitated microbial extracellular electron transfer in electrogenic granular sludge via geobattery mechanism.

Electroactive pyrogenic carbon (PC) is an intriguing candidate for realizing the ambitious goals of large-scale applications of microbial electrochemical technologies (METs). In this study, PC was employed to promote the extracellular electron transfer (EET) within the electrogenic granular sludge (EGS) by acting as an electron conduit. The pecan shell-derived PC prepared at three temperatures (600, 800, and 1000 ˚C) contained rich oxygenated-functional moieties (mainly quinone) on the surface, endowing a good electron transfer capacity (EEC). The maximum current density (Jmax) of EGS with PC amendment outperformed the control EGS without PC amendment, i.e., 100-132 times higher than Jamx of EGS in the absence of PC. Among various pyrolysis temperatures, the PC derived from 600 ˚C produced the highest Jmax (0.40 A/ m2), 0.67-times, and 0.33-times higher than that of PC derived from 800 and 1000 ˚C, respectively. Furthermore, more polysaccharides were secreted in extracellular polymeric substance with PC amendments. The microbial community analysis demonstrated that the PC favored the growth of electroactive bacteria over methanogens. The metabolic pathway revealed that PC induced more functional enzymes in the quinone biosynthesis and cytochrome c and heme synthesis, resulting in an enhanced EET. The EEC of PC was responsible for the EET enhancement effect via PC acting as a geobattery to wire up the EGS and electrodes. Overall, this study pinpoints the finding of PC role in a mixed electroactive biofilm and provides a wide scenario of the PC applications in MET at large scales.

Removal of Arsenate From Groundwater by Cathode of Bioelectrochemical System Through Microbial Electrosorption, Reduction, and Sulfuration.

Arsenate [As(V)] is a toxic metalloid and has been observed at high concentrations in groundwater globally. In this study, a bioelectrochemical system (BES) was used to efficiently remove As(V) from groundwater, and the mechanisms involved were systematically investigated. Our results showed that As(V) can be efficiently removed in the BES cathode chamber. When a constant cell current of 30 mA (I cell , volume current density = 66.7 A/m3) was applied, 90 ± 3% of total As was removed at neutral pH (7.20-7.50). However, when I cell was absent, the total As in the effluent, mainly As(V), had increased approximately 2-3 times of the As(V) in influent. In the abiotic control reactor, under the same condition, no significant total As or As(V) removal was observed. These results suggest that As(V) removal was mainly ascribed to microbial electrosorption of As(V) in sludge. Moreover, part of As(V) was bioelectrochemically reduced to As(III), and sulfate was also reduced to sulfides [S(-II)] in sludge. The XANES results revealed that the produced As(III) reacted with S(-II) to form As2S3, and the residual As(III) was microbially electroadsorbed in sludge. This BES-based technology requires no organic or chemical additive and has a high As(V) removal efficiency, making it an environment-friendly technique for the remediation of As-contaminated groundwater.

Progress in Mo/W-based electrocatalysts for nitrogen reduction to ammonia under ambient conditions.

Ammonia (NH3), possessing high hydrogen content and energy density, has been widely employed for fertilizers and value-added chemicals in green energy carriers and fuels. However, the current NH3 synthesis largely depends on the traditional Haber-Bosch process, which needs tremendous energy consumption and generates greenhouse gas, resulting in severe energy and environmental issues. The electrochemical strategy of converting N2 to NH3 under mild conditions is a potentially promising route to realize an environmentally friendly concept. Among various catalysts, molybdenum/tungsten-based electrocatalysts have been widely used in electrochemical catalytic and energy conversion. This review describes the latest progress of molybdenum/tungsten-based electrocatalysts for the electrochemical nitrogen reduction reaction. The fundamental roles of morphology, doping, defects, heterojunction, and coupling regulation in improving electrocatalytic performance are mainly discussed. Besides, some tailoring strategies for enhancing the conversion efficiency of N2 to NH3 over Mo/W-based electrocatalysts are also summarized. Finally, the existing challenges and limitations of N2 fixation are proposed, as well as possible future perspectives, which will provide a platform for further development of advanced Mo/W-based N2 reduction systems.

Atomically Dispersed Zinc(I) Active Sites to Accelerate Nitrogen Reduction Kinetics for Ammonia Electrosynthesis.

Developing highly active and stable nitrogen reduction reaction (NRR) catalysts for NH3 electrosynthesis remains challenging. Herein, an unusual NRR electrocatalyst is reported with a single Zn(I) site supported on hollow porous N-doped carbon nanofibers (Zn1 N-C). The Zn1 N-C nanofibers exhibit an outstanding NRR activity with a high NH3 yield rate of ≈16.1 µg NH3 h-1 mgcat -1 at -0.3 V and Faradaic efficiency (FE) of 11.8% in alkaline media, surpassing other previously reported carbon-based NRR electrocatalysts with transition metals atomically dispersed and nitrogen coordinated (TM-Nx ) sites. 15 N2 isotope labeling experiments confirm that the feeding nitrogen gas is the only nitrogen source in the production of NH3 . Structural characterization reveals that atomically dispersed Zn(I) sites with Zn-N4 moieties are likely the active sites, and the nearby graphitic N site synergistically facilitates the NRR process. In situ attenuated total reflectance-Fourier transform infrared measurement and theoretical calculation elucidate that the formation of initial *NNH intermediate is the rate-limiting step during the NH3 production. The graphitic N atoms adjacent to the tetracoordinate Zn-N4 moieties could significantly lower the energy barrier for this step to accelerate hydrogenation kinetics duing the NRR.