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.

Factors driving antimony accumulation in soil-pakchoi and wheat agroecosystems: Insights and predictive models.

The accumulation of antimony (Sb) in plants and its potential effects on human health are of increasing concern. Nevertheless, only a few countries or regions have established soil Sb thresholds for agricultural purposes, and soil properties have not been taken into account. This study investigated the accumulation of Sb in the edible parts of pakchoi and wheat grain by adding exogenous Sb to 21 soils with varying properties. The results revealed a positive correlation between bioavailable Sb (Sbava, extracted by 0.1 M K2HPO4) in soil and Sb in the edible parts of pakchoi (R2 = 0.77, p < 0.05) and wheat grain (R2 = 0.54, p < 0.05). Both machine learning and traditional multiple regression analysis indicated Sbava was the most critical feature and the main soil properties that contributed to Sb uptake by pakchoi and wheat were CaCO3 and clay, respectively. The advisory food limits for Sb in pakchoi and wheat were estimated based on health risk assessment, and used to derive soil thresholds for safe pakchoi and wheat production based on Sbtot and Sbava, respectively. These findings hold potential for predicting Sb uptake by crops with different soil properties and informing safe production management strategies.

Matched Kinetics Process Over Fe2O3-Co/NiO Heterostructure Enables Highly Efficient Nitrate Electroreduction to Ammonia.

Tandem nitrate electroreduction reaction (NO3 -RR) is a promising method for green ammonia (NH3) synthesis. However, the mismatched kinetics processes between NO3 --to-NO2 - and NO2 --to-NH3 results in poor selectivity for NH3 and excess NO2 - evolution in electrolyte solution. Herein, a Ni2+ substitution strategy for developing oxide heterostructure in Co/Fe layered double oxides (LDOs) was designed and employed as tandem electrocataltysts for NO3 -RR. (Co0.83Ni0.16)2Fe exhibited a high NH3 yield rate of 50.4 mg ⋅ cm-2 ⋅ h-1 with a Faradaic efficiency of 97.8 % at -0.42 V vs. reversible hydrogen electrode (RHE) in a pulsed electrolysis test. By combining with in situ/operando characterization technologies and theoretical calculations, we observed the strong selectivity of NH3 evolution over (Co0.83Ni0.16)2Fe, with Ni playing a dual role in NO3 -RR by i) modifying the electronic behavior of Co, and ii) serving as complementary site for active hydrogen (*H) supply. Therefore, the adsorption capacity of *NO2 and its subsequent hydrogenation on the Co sites became more thermodynamically feasible. This study shows that Ni substitution promotes the kinetics of the NO3 -RR and provides insights into the design of tandem electrocatalysts for NH3 evolution.

Constructing Gold Single-Atom Catalysts on Hierarchical Nitrogen-Doped Carbon Nanocages for Carbon Dioxide Electroreduction to Syngas.

Precious-metal single-atom catalysts (SACs), featured by high metal utilization and unique coordination structure for catalysis, demonstrate distinctive performances in the fields of heterogeneous and electrochemical catalysis. Herein, gold SACs are constructed on hierarchical nitrogen-doped carbon nanocages (hNCNC) via a simple impregnation-drying process and first exploited for electrocatalytic carbon dioxide reduction reaction (CO2RR) to produce syngas. The as-constructed Au SAC exhibits the high mass activity of 3319 A g-1 Au at -1.0 V (vs reversible hydrogen electrode, RHE), much superior to the Au nanoparticles supported on hNCNC. The ratio of H2/CO can be conveniently regulated in the range of 0.4-2.2 by changing the applied potential. Theoretical study indicates such a potential-dependent H2/CO ratio is attributed to the different responses of HER and CO2RR on Au single-atom sites coordinating with one N atom at the edges of micropores across the nanocage shells. The catalytic mechanism of the Au active sites is associated with the smooth switch between twofold and fourfold coordination during CO2RR, which much decreases the free energy changes of the rate-determining steps and promotes the reaction activity.

Spontaneous generation of singlet oxygen on microemulsion-derived manganese oxides with rich oxygen vacancies for efficient aerobic oxidation.

Developing innovative catalysts for efficiently activating O2 into singlet oxygen (1O2) is a cutting-edge field with the potential to revolutionize green chemical synthesis. Despite its potential, practical implementation remains a significant challenge. In this study, we design a series of nitrogen (N)-doped manganese oxides (Ny-MnO2, where y represents the molar amount of the N precursor used) nanocatalysts using compartmentalized-microemulsion crystallization followed by post-calcination. These nanocatalysts demonstrate the remarkable ability to directly produce 1O2 at room temperature without the external fields. By strategically incorporating defect engineering and interstitial N, the concentration of surface oxygen atoms (Os) in the vicinity of oxygen vacancy (Ov) reaches 51.1% for the N55-MnO2 nanocatalyst. This feature allows the nanocatalyst to expose a substantial number of Ov and interstitial N sites on the surface of N55-MnO2, facilitating effective chemisorption and activation of O2. Verified through electron paramagnetic resonance spectroscopy and reactive oxygen species trapping experiments, the spontaneous generation of 1O2, even in the absence of light, underscores its crucial role in aerobic oxidation. Density functional theory calculations reveal that an increased Ov content and N doping significantly reduce the adsorption energy, thereby promoting chemisorption and excitation of O2. Consequently, the optimized N55-MnO2 nanocatalyst enables room-temperature aerobic oxidation of alcohols with a yield surpassing 99%, representing a 6.7-fold activity enhancement compared to ε-MnO2 without N-doping. Furthermore, N55-MnO2 demonstrates exceptional recyclability for the aerobic oxidative conversion of benzyl alcohol over ten cycles. This study introduces an approach to spontaneously activate O2 for the green synthesis of fine chemicals.

Developing Ni single-atom sites in carbon nitride for efficient photocatalytic H2O2 production.

Photocatalytic two-electron oxygen reduction to produce high-value hydrogen peroxide (H2O2) is gaining popularity as a promising avenue of research. However, structural evolution mechanisms of catalytically active sites in the entire photosynthetic H2O2 system remains unclear and seriously hinders the development of highly-active and stable H2O2 photocatalysts. Herein, we report a high-loading Ni single-atom photocatalyst for efficient H2O2 synthesis in pure water, achieving an apparent quantum yield of 10.9% at 420 nm and a solar-to-chemical conversion efficiency of 0.82%. Importantly, using in situ synchrotron X-ray absorption spectroscopy and Raman spectroscopy we directly observe that initial Ni-N3 sites dynamically transform into high-valent O1-Ni-N2 sites after O2 adsorption and further evolve to form a key *OOH intermediate before finally forming HOO-Ni-N2. Theoretical calculations and experiments further reveal that the evolution of the active sites structure reduces the formation energy barrier of *OOH and suppresses the O=O bond dissociation, leading to improved H2O2 production activity and selectivity.

Developing a class of dual atom materials for multifunctional catalytic reactions.

Dual atom catalysts, bridging single atom and metal/alloy nanoparticle catalysts, offer more opportunities to enhance the kinetics and multifunctional performance of oxygen reduction/evolution and hydrogen evolution reactions. However, the rational design of efficient multifunctional dual atom catalysts remains a blind area and is challenging. In this study, we achieved controllable regulation from Co nanoparticles to CoN4 single atoms to Co2N5 dual atoms using an atomization and sintering strategy via an N-stripping and thermal-migrating process. More importantly, this strategy could be extended to the fabrication of 22 distinct dual atom catalysts. In particular, the Co2N5 dual atom with tailored spin states could achieve ideally balanced adsorption/desorption of intermediates, thus realizing superior multifunctional activity. In addition, it endows Zn-air batteries with long-term stability for 800 h, allows water splitting to continuously operate for 1000 h, and can enable solar-powered water splitting systems with uninterrupted large-scale hydrogen production throughout day and night. This universal and scalable strategy provides opportunities for the controlled design of efficient multifunctional dual atom catalysts in energy conversion technologies.

Coupling of Dissolved Organic Matter Molecular Fractionation with Iron and Sulfur Transformations during Sulfidation-Reoxidation Cycling.

Iron (oxyhydr)oxides and organic matter (OM) are intimately associated in natural environments, and their fate might be linked to sulfur during sulfidation-reoxidation cycling. However, the coupling of DOM molecular fractionation with Fe and S transformations following a full sulfidation-reoxidation cycle remains poorly understood. Here, we reacted Fh and Fh-OM associations with S(-II) anaerobically and then exposed the sulfidic systems to air. S(-II) preferentially reacted with Fh to form inorganic S (e.g., mackinawite, S0, and S22-) over being incorporated into OM as organic S and therefore indirectly affected OM fate by altering Fe speciation. Fh sulfidation was inhibited by associated OM, and the main secondary Fe species were mackinawite, Fe(II)-OM compounds, and lepidocrocite. Concomitantly, organic molecules high in unsaturation, aromaticity, and molecular weight were detached from solid-phase Fe species due to their lower affinities for secondary Fe species than for Fh. During the reoxidation stage, the previously formed Fe(II) species were reoxidized to Fh with a stronger aggregation, which recaptured formerly released OM with higher selectivity. Additionally, •OH was generated from Fe(II) oxygenation and degraded a portion of the DOM molecules. Overall, these results have significant implications for Fe, C, and S cycling in S-rich environments characterized by oscillating redox conditions.

Theoretical study on the inhibition mechanisms of heavy metal ions on urease activity.

Soil urease is highly sensitive to soil heavy metal pollution, and thus its activity can be used as bio-indicator of soil health. However, little is known about the inhibition mechanisms of heavy metals on urease. The effects of dimetallic substitution (i.e., Cd, Co, Cu, Hg, and Zn) on the binding of urea in the urease and its subsequent decomposition were studied using quantum chemical methodologies with a urease mimic (phthalazine-dinickel complex). The dimetallic substitution altered the structural features of the dimetal complexes and the M-O bond length between the dimetals and the carbonyl-O of coordinated urea molecules, weakening the binding energies of urea in dimetal complexes, which further affected the transformation of urea. In the urea decomposition via intra-molecular proton transfer, all dimetal complexes have a high activation barrier due to the weak binding of urea in complexes and hydrogen bonding within urea molecules, which are therefore difficult to occur spontaneously. In the urea decomposition via water-assisted inter-molecular proton transfer, the addition of water molecules decreased the energy barrier of urea decomposition. Regardless of the urea decomposition pathway, the dimetallic substitution altered the M-O bond length and hydrogen bond pattern of intermediates and transition states, and also affected the leave of the resulting NH3 from the dimetal complexes by regulating the C-N bond length within the decomposed urea molecule. Overall, the theoretical study provided insight into the molecular mechanisms of the inhibitory effects of heavy metals on urease activity.

Manipulating local coordination of copper single atom catalyst enables efficient CO2-to-CH4 conversion.

Electrochemical CO2 conversion to methane, powered by intermittent renewable electricity, provides an entrancing opportunity to both store renewable electric energy and utilize emitted CO2. Copper-based single atom catalysts are promising candidates to restrain C-C coupling, suggesting feasibility in further protonation of CO* to CHO* for methane production. In theoretical studies herein, we find that introducing boron atoms into the first coordination layer of Cu-N4 motif facilitates the binding of CO* and CHO* intermediates, which favors the generation of methane. Accordingly, we employ a co-doping strategy to fabricate B-doped Cu-Nx atomic configuration (Cu-NxBy), where Cu-N2B2 is resolved to be the dominant site. Compared with Cu-N4 motifs, as-synthesized B-doped Cu-Nx structure exhibits a superior performance towards methane production, showing a peak methane Faradaic efficiency of 73% at -1.46 V vs. RHE and a maximum methane partial current density of -462 mA cm-2 at -1.94 V vs. RHE. Extensional calculations utilizing two-dimensional reaction phase diagram analysis together with barrier calculation help to gain more insights into the reaction mechanism of Cu-N2B2 coordination structure.

Modeling the Interaction and Uptake of Cd-As(V) Mixture to Wheat Roots Affected by Humic Acids, in Terms of root cell Membrane Surface Potential (ψ0).

The joint toxicological effects of Cd2+ and As(V) mixture on wheat root as affected by environmental factors, such as pH, coexisting cations, and humic acids etc., were investigated using hydroponic experiments. The interaction and toxicological mechanisms of co-existing Cd2+ and As(V) at the interface of solution and roots in presence of humic acid were further explored by incorporating root cell membrane surface potential ψ0 into a mechanistic model of combined biotic ligand model (BLM)-based Gouy-Chapman-Stern (GCS) model and NICA-DONNAN model. Besides, molecular dynamics (MD) simulations of lipid bilayer equilibrated with solution containing Cd2+ and H2AsO4- further revealed the molecular distribution of heavy metal(loid) ions under different membrane surface potentials. H2AsO4- and Cd2+ can be adsorbed on the surface of the membrane alone or as complexes, which consolidate the limitation of the macroscopic physical models.

Phosphorus doping significantly enhanced the catalytic performance of cobalt-single-atom catalyst for peroxymonosulfate activation and contaminants degradation.

Increasing studies have been conducted to explore strategies for enhancing the catalytic performance of metal-doped C-N-based materials (e.g., cobalt (Co)-doped C3N5) via heteroatomic doping. However, such materials have been rarely doped by phosphorus (P) with the higher electronegativity and coordination capacity. In current study, a novel P and Co co-doped C3N5 (Co-xP-C3N5) was developed for peroxymonosulfate (PMS) activation and 2,4,4'-trichlorobiphenyl (PCB28) degradation. The PCB28 degradation rate increased by 8.16-19.16 times with Co-xP-C3N5 compared to conventional activators under similar reaction conditions (e.g., PMS concentration). The state-of-the-art techniques, including X-ray absorption spectroscopy and electron paramagnetic resonance etc., were applied to explore the mechanism of P doping for enhancing Co-xP-C3N5 activation. Results showed that P doping induced the formation of Co-P and Co-N-P species, which increased the contents of coordinated Co and improved Co-xP-C3N5 catalytic performance. The Co mainly coordinated with the first shell layer of Co1-N4, with successful P doping occurring in the second shell layer of Co1-N4. The P doping favored electron transfer from the C to N atom near Co sites and thus strengthened PMS activation owing to its higher electronegativity. These findings provide new strategy for enhancing the performance of single atom-based catalysts for oxidant activation and environmental remediation.

Sabatier Phenomenon in Hydrogenation Reactions Induced by Single-Atom Density.

The Sabatier principle is a fundamental concept in heterogeneous catalysis that provides guidance for designing optimal catalysts with the highest activities. For the first time, we here report a new Sabatier phenomenon in hydrogenation reactions induced by single-atom density at the atomic scale. We produce a series of Ir single-atom catalysts (SACs) with a predominantly Ir1-P4 coordination structure with densities ranging from 0.1 to 1.7 atoms/nm2 through a P-coordination strategy. When used as the catalysts for hydrogenation, a volcano-type relationship between Ir single-atom density and hydrogenation activity emerges, with a summit at a moderate density of 0.7 atoms/nm2. Mechanistic studies show that the balance between adsorption and desorption strength of the activated H* on Ir single atoms is found to be a key factor for the Sabatier phenomenon. The transferred Bader charge on these Ir SACs is proposed as a descriptor to interpret the structure-activity relationship. In addition, the maximum activity and selectivity can be simultaneously achieved in chemoselective hydrogenation reactions with the optimized catalyst due to the uniform geometric and electronic structures of single sites in SACs. The present study reveals the Sabatier principle as an insightful guidance for the rational design of more efficient and practicable SACs for hydrogenation reactions.

Electrosynthesis of polymer-grade ethylene via acetylene semihydrogenation over undercoordinated Cu nanodots.

The removal of acetylene impurities remains important yet challenging to the ethylene downstream industry. Current thermocatalytic semihydrogenation processes require high temperature and excess hydrogen to guarantee complete acetylene conversion. For this reason, renewable electricity-based electrocatalytic semihydrogenation of acetylene over Cu-based catalysts is an attractive route compared to the energy-intensive thermocatalytic processes. However, active Cu electrocatalysts still face competition from side reactions and often require high overpotentials. Here, we present an undercoordinated Cu nanodots catalyst with an onset potential of -0.15 V versus reversible hydrogen electrode that can exclusively convert C2H2 to C2H4 with a maximum Faradaic efficiency of ~95.9% and high intrinsic activity in excess of -450 mA cm-2 under pure C2H2 flow. Subsequently, we successfully demonstrate simulated crude ethylene purification, continuously producing polymer-grade C2H4 with <1 ppm C2H2 for 130 h at a space velocity of 1.35 × 105 ml gcat-1 h-1. Theoretical calculations and in situ spectroscopies reveal a lower energy barrier for acetylene semihydrogenation over undercoordinated Cu sites than nondefective Cu surface, resulting in the excellent C2H2-to-C2H4 catalytic activity of Cu nanodots.

Regulating the electronic structure through charge redistribution in dense single-atom catalysts for enhanced alkene epoxidation.

Inter-site interaction in densely populated single-atom catalysts has been demonstrated to have a crucial role in regulating the electronic structure of metal atoms, and consequently their catalytic performances. We herein report a general and facile strategy for the synthesis of several densely populated single-atom catalysts. Taking cobalt as an example, we further produce a series of Co single-atom catalysts with varying loadings to investigate the influence of density on regulating the electronic structure and catalytic performance in alkene epoxidation with O2. Interestingly, the turnover frequency and mass-specific activity are significantly enhanced by 10 times and 30 times with increasing Co loading from 5.4 wt% to 21.2 wt% in trans-stilbene epoxidation, respectively. Further theoretical studies reveal that the electronic structure of densely populated Co atoms is altered through charge redistribution, resulting in less Bader charger and higher d-band center, which are demonstrated to be more beneficial for the activation of O2 and trans-stilbene. The present study demonstrates a new finding about the site interaction in densely populated single-atom catalysts, shedding insight on how density affects the electronic structure and catalytic performance for alkene epoxidation.

Changes in molybdenum bioaccessibility in four spiked soils with respect to soil pH and organic matter.

Investigation of the inherent relationship between soil physicochemical properties and pollutant's bioaccessibility (BAc) by analyzing different soil types may produce erroneous results or bias, owing to the complexity of natural soil characteristics. However, use of single factor analysis (e.g., soil pH, organic matter) facilitates evaluation of the transition. In this study, the inherent relationship between soil properties and the BAc of molybdenum (Mo) was evaluated in two typical variable-charge soils (Ferralosol and Ferrosol) and constant-charge soils (Alfisol and Inceptisol) spiked with Mo after adjusting their pH and organic carbon content. The Unified Bioaccessibility Research Group of Europe (BARGE) Method (UBM) was applied to evaluate the BAc of Mo in the gastric and intestinal phase (GP and IP, respectively). Isothermal adsorption experiment, Tessier sequential extraction, and field emission scanning electron microscope-energy dispersive spectroscopy (FESEM-EDS) analysis were conducted on these spiked soils. The results indicated that the BAc of Mo in IP (27.42-80.41%) was significantly higher than that in GP (2.52-28.53%). A significantly lower level of BAc of Mo was found in the variable-charge soils, when compared with that in the constant-charge soils. Furthermore, significant negative correlations were identified between the BAc and adsorption of Mo, which decreased with soil pH. These negative correlations can be attributed to the increase in soil negative charge density and enhancement of Mo desorption by hydroxyl, which reinforce the repulsion between Mo and soil particles with increasing soil pH; this was further confirmed by the decrease in Mo adsorption with Alfisol pH. The Mo fractions and FESEM-EDS patterns confirmed that the BAc of Mo in GP was negatively correlated with soil organic carbon (SOC) content, possibly owing to an increase in Mo retention by SOC. These findings indicated that the health risk of Mo contamination in low pH and SOC-rich variable-charge soil is relatively low, thus providing references for rationalizing risk assessment and remediating Mo-polluted soil.

Selective CO2 electrolysis to CO using isolated antimony alloyed copper.

Renewable electricity-powered CO evolution from CO2 emissions is a promising first step in the sustainable production of commodity chemicals, but performing electrochemical CO2 reduction economically at scale is challenging since only noble metals, for example, gold and silver, have shown high performance for CO2-to-CO. Cu is a potential catalyst to achieve CO2 reduction to CO at the industrial scale, but the C-C coupling process on Cu significantly depletes CO* intermediates, thus limiting the CO evolution rate and producing many hydrocarbon and oxygenate mixtures. Herein, we tune the CO selectivity of Cu by alloying a second metal Sb into Cu, and report an antimony-copper single-atom alloy catalyst (Sb1Cu) of isolated Sb-Cu interfaces that catalyzes the efficient conversion of CO2-to-CO with a Faradaic efficiency over 95%. The partial current density reaches 452 mA cm-2 with approximately 91% CO Faradaic efficiency, and negligible C2+ products are observed. In situ spectroscopic measurements and theoretical simulations reason that the atomic Sb-Cu interface in Cu promotes CO2 adsorption/activation and weakens the binding strength of CO*, which ends up with enhanced CO selectivity and production rates.

A molecular level understanding of antimony immobilization mechanism on goethite by the combination of X-ray absorption spectroscopy and density functional theory calculations.

A molecular level understanding of antimony (Sb) immobilization mechanism on Fe oxides is required to clarify the fate of Sb in the soil. In this study, macroscopic sorption experiments, combined with extended X-ray absorption fine structure (EXAFS) spectroscopy and density functional theory (DFT), were utilized to explore the interaction between Sb and goethite. The ion strength has no effect on Sb sorption on goethite, indicating the inner-sphere complex Sb formed on goethite. Goethite has the higher sorption potential to Sb(III) than Sb(V), consistent with the higher thermodynamic stability of the geometry for Sb(III) formed on goethite than Sb(V) revealed by DFT calculations. By comparing the Sb-Fe distances obtained by EXAFS spectroscopy and DFT, eight kinds of Sb(III) surface complexes and nine kinds of Sb(V) surface complexes were considered to be the possible geometries Sb formed on different crystal planes of goethite, including monodentate mononuclear, bidentate mononuclear, bidentate binuclear, tridentate mononuclear, tridentate binuclear, tridentate four-nuclear complexes. The structural and energetic details of these filtered geometries provide comprehensive information on Sb immobilization mechanism on goethite, helpful in clarifying the fate of Sb in soils.

Axial N Ligand-Modulated Ultrahigh Activity and Selectivity Hyperoxide Activation over Single-Atoms Nanozymes.

Learning and studying the structure-activity relationship in the bio-enzymes is conducive to the design of nanozymes for energy and environmental application. Herein, Fe single-atom nanozymes (Fe-SANs) with Fe-N5 site, inspired by the structure of cytochromes P450 (CYPs), are developed and characterized. Similar to the CYPs, the hyperoxide can activate the Fe(III) center of Fe-SANs to generate Fe(IV)O intermediately, which can transfer oxygen to the substrate with ultrafast speed. Particularly, using the peroxymonosulfate (PMS)-activated Fe-SANs to oxidize sulfamethoxazole, a typical antibiotic contaminant, as the model hyperoxides activation reaction, the excellent activity within 284 min-1 g-1 (catalyst) mmol-1 (PMS) oxidation rate and 91.6% selectivity to the Fe(IV)O intermediate oxidation are demonstrated. More importantly, instead of promoting PMS adsorption, the axial N ligand modulates the electron structure of FeN5 SANs for the lower reaction energy barrier and promotes electron transfer to PMS to produce Fe(IV)O intermediate with high selectivity. The highlight of the axial N coordination in the nanozymes in this work provides deep insight to guide the design and development of nanozymes nearly to the bio-enzyme with excellent activity and selectivity.

A Template Editing Strategy to Create Interlayer-Confined Active Species for Efficient and Durable Oxygen Evolution Reaction.

Substantial overpotentials and insufficient and unstable active sites of oxygen evolution reaction (OER) electrocatalysts limit their efficiency and stability in OER-related energy conversion and storage technologies. Here, a template editing strategy is proposed to graft highly active catalytic species onto highly conductive rigid frameworks to tackle this challenge. As a successful attempt, two types of NiO6 units of layered Ni BDC (BDC stands for 1,4-benzenedicarboxylic acid) metal organic frameworks are selectively edited by chemical etching-assisted electroxidation to create layered γ-NiOOH with intercalated Ni-O species. In such an interlayer-confined intercalated architecture, the large interlayer space with high ion permeability offers an ideal reaction region to sufficiently expose the OER active sites comprising high-density intercalated Ni-O species, which also suppresses the undesirable γ to ß phase transformation, thus exhibiting efficient and durable OER activity. As a result, water oxidation can occur at an extremely low overpotential of 130 mV and affords 1000 h stability at 100 mA cm-2 . The strategy conceptually shows the possibility of achieving stable homogeneous-like catalysis in heterogeneous catalysis.