Intermediate Energies Research Articles

Oxygen vacancy-rich Nd-doped RuO2 for efficient acid overall water splitting

The development of highly active and acid-stable Ru-based electrocatalysts is of great significance for water electrolysis but remains a huge challenge due to serious Ru corrosion in an acid medium. Herein, we prepared oxygen vacancy (OV)-rich Nd-doped RuO2 nanocrystals by facile synthesis via hydrothermal and subsequent annealing for efficient overall water splitting. The catalyst exhibits an overpotential of only 200 mV for OER and 44 mv for HER at the current density of 10 mA cm−2 in 0.5 M H2SO4 electrolyte. Nd-doped RuO2 only demands a cell voltage of 1.52 V to drive the overall water splitting reaction and displays excellent stability for 100 h. Density functional theory further revealed that the newly constructed Nd-doped RuO2 sites activate the difficult to react *O intermediates, reducing the adsorption energy of the OER intermediates to effectively minimize the Gibbs free energy (*O to *OOH) of the reaction rate-determining step and regulate the center of the active site d-band. The synergistic effect of aliovalent doping and vacancy engineering contributes to the excellent electrocatalytic performance of Nd-doped RuO2. This performance control strategy can pave the way for the development of effective and economically viable catalysts.

Reconstructing the Coordination Environment of Fe/Co Dual-atom Sites towards Efficient Oxygen Electrocatalysis for Zn-Air Batteries.

Dual-atom catalysts with nitrogen-coordinated metal sites embedded in carbon can drive the oxygen reduction and evolution reactions (ORR/OER) in rechargeable zinc-air batteries (ZABs), and the further improvement is limited by the linear scaling relationship of intermediate binding energies in the absorbate evolution mechanism (AEM). Triggering the lattice oxygen mechanism (LOM) is promising to overcome this challenge, but has yet been verified since the lacking of bridge oxygen (O) in the rigid coordination environment of the metal centers. Here, we demonstrate that suitably tailored dual-atom catalysts of FeCo-N-C can undergo out-plane and in-plane reconstruction to form the both axial O and bridge O at the metal centers, and thus activate the LOM pathway. The tailored FeCo-N-C with shortened Fe-N bonds also favor the ORR process, therefore is a promising dual-atom oxygen catalyst. The assembled rechargeable ZABs demonstrate a peak power density of 332 mW cm-2, and exhibit no notable decline after ~ 720 h of continuous cycling.

Au-Doped Black Silicon Photodetector Fabricated by a Femtosecond Laser with Excellent Near-Infrared Response.

Silicon photonic devices are key components in optical imaging and sensing for communication, and the development of silicon-based photodetectors with ideal performance in the visible and infrared spectral ranges can promote the application of silicon photonics in various photoelectronic systems. Here, a Au-doped black silicon photodetector was prepared by a femtosecond laser direct writing technique. The conical micro-/nanostructures with different sizes were produced by different laser fluence irradiation. Ultrafast pump-probe technology revealed that the strong spallation process and phase explosion between Au and silicon facilitate the interfusion of Au atoms into the silicon lattice. EDS analyses, Raman spectra, and XPS spectra show the uniform distribution of Au elements, multiconfiguration amorphous phase transition, and stable chemical valence states of Au elements in Au-doped black silicon layers, respectively. The excellent geometric light trapping performance of the surface conic structure-assisted photodetector achieved a high absorptance of 95% in the 200-1100 nm band. Simultaneously, the introduction of the intermediate band by Au hyperdoping also leads to a strong absorptance of 75% in the 1100-2500 nm band. The photoelectrical response rate of the Au-doped black silicon photodetectors increased by 10 times in the infrared wavelength band by means of the introduced intermediate energy levels through Au element doping. The switching photocurrent ratio is also found to be boosted 10 times, which comes from the reduction of the photon injection barrier. The excellent photoelectronic properties lead to the increased potential of femtosecond laser processing for integration with photonics and electronics, which shows great possibilities in the further progress of energy devices, information technology, and artificial intelligence.

Proton bunch monitors for the clinical translation of prompt gamma-ray timing

Objective. Prompt gamma-ray timing is an emerging technology in the field of particle therapy treatment verification. This system measures the arrival times of gamma rays produced in the patient body and uses the cyclotron radio frequency signal as time reference for the beam micro-bunches. Its translation into clinical practice is currently hindered by observed instabilities in the phase relation between the cyclotron radio frequency and the measured arrival time of prompt gamma rays. To counteract this, two proton bunch monitors are presented, integrated into the prompt gamma-ray timing workflow and evaluated.Approach. The two monitors are (a) a diamond detector placed at the beam energy degrader, and (b) a cyclotron monitor signal measuring the phase difference between dee current and voltage. First, the two proton bunch monitors as well as their mutual correlation were characterized. Then, a prompt gamma-ray timing measurement was performed aiming to quantify the present magnitude of the phase instabilities and to evaluate the ability of the proton bunch monitors to correct for these instabilities.Main results. It was found that the two new monitors showed a very high correlation for intermediate proton energies after the first second of irradiation, and that they were able to reduce fluctuations in the detected phase of prompt gamma rays. Furthermore, the amplitude of the phase instabilities had intrinsically decreased from about 700 ps to below 100 ps due to cyclotron upgrades.Significance. The uncertainty of the prompt gamma-ray timing method for proton treatment verification was reduced. For routine clinical application, challenges remain in accounting for detector load effects, temperature drifts and throughput limitations.

Achieving a Thermodynamic Self‐Regulation Dynamic Adsorption Mechanism for Ammonia Synthesis through Selective Orbital Coupling

With the continuous pursuing on the improvement of catalytic activity, a catalyst performed exceeding catalytic volcano plots is desired, while it is impeded by the adsorption‐energy scaling relations of reaction intermediates. Numerous efforts have been focused on optimizing the initial and final intermediates to circumvent the scaling relations for an improved performance. For a step forward, simultaneously optimizing all intermediates is essential to explore the theoretical maximum of catalytic activity. Herein, we proposed a dynamic adsorption mechanism (DAM) to independently regulate the adsorption configurations of all intermediates of electrochemical nitrogen reduction reaction (NRR). To demonstrate the DAM, a multi‐site NbNi3 intermetallic is developed, which enables suitable adsorption energies of different intermediates via modulating orbital coupling mechanisms. As a result, NbNi3 achieves an ultra‐low limiting potential of NRR of −0.11 V vs. reversible hydrogen electrode (RHE). Strikingly, the theoretical result is confirmed by a proof‐of‐concept experiment, wherein the nanoporous NbNi3 electrode exhibits a remarkable NH3 yield rate of 25.89 μg h−1 cm−2 with the Faradic efficiency of 33.15% at −0.25 V vs. RHE. Overall, this work brings out a new strategy to avoid the scaling relations, and opens up a promising avenue toward high‐efficiency NRR catalysts.

Machine-Learning-Assisted Screening of Nanocluster Electrocatalysts: Mapping and Reshaping the Activity Volcano for the Oxygen Reduction Reaction.

In computational heterogeneous catalysis, Sabatier's principle-based activity volcano plots provide an intuitive guide to catalyst design but impose a fundamental constraint on the maximum achievable catalytic performance. Recently, subnano clusters have emerged as an exciting platform, offering high noble metal utilization and superior performance for various reactions compared to extended surfaces, reflecting a complex structure-activity relationship in the non-scalable regime. However, understanding their non-monotonic catalytic activity, attributed to the large configurational space and their fluxional identity, poses a formidable challenge. Here, we present a machine learning (ML) framework that captures the non-monotonic trends in oxygen reduction reaction (ORR) activity at the subnanometer scale, attributed to their dynamic fluxional characteristics. We demonstrate a size-dependent shifting and reshaping of the ORR activity volcano, with Au replacing Pt at the peak. Leveraging only upon the non-ab initio geometric and electronic properties, our trained ML model accurately captures the site-specific adsorption energies of intermediates at the subnanometer regime. To account for the inconsistent trend in activity, we analyzed the correlation between electronic and geometric properties. Our findings reveal that the d-filling and coupling matrix of the neighboring metal atom significantly influences the intermediate adsorption on the local chemical environment compared to the d-band center. Following this analysis, we utilized ML to map the catalyst distribution in the activity volcano and identified the five best sub-nano electrocatalysts, demonstrating overpotential values lower than or comparable to the Pt(111) surface for the ORR. This study provides intuitive guidelines for the rational designing of highly efficient electrocatalysts for fuel cell applications while modifying the activity volcano plots for electrocatalysts at the subnanometer regime.

Achieving a Thermodynamic Self-Regulation Dynamic Adsorption Mechanism for Ammonia Synthesis through Selective Orbital Coupling.

With the continuous pursuing on the improvement of catalytic activity, a catalyst performed exceeding catalytic volcano plots is desired, while it is impeded by the adsorption-energy scaling relations of reaction intermediates. Numerous efforts have been focused on optimizing the initial and final intermediates to circumvent the scaling relations for an improved performance. For a step forward, simultaneously optimizing all intermediates is essential to explore the theoretical maximum of catalytic activity. Herein, we proposed a dynamic adsorption mechanism (DAM) to independently regulate the adsorption configurations of all intermediates of electrochemical nitrogen reduction reaction (NRR). To demonstrate the DAM, a multi-site NbNi3 intermetallic is developed, which enables suitable adsorption energies of different intermediates via modulating orbital coupling mechanisms. As a result, NbNi3 achieves an ultra-low limiting potential of NRR of -0.11 V vs. reversible hydrogen electrode (RHE). Strikingly, the theoretical result is confirmed by a proof-of-concept experiment, wherein the nanoporous NbNi3 electrode exhibits a remarkable NH3 yield rate of 25.89 μg h-1 cm-2 with the Faradic efficiency of 33.15% at -0.25 V vs. RHE. Overall, this work brings out a new strategy to avoid the scaling relations, and opens up a promising avenue toward high-efficiency NRR catalysts.

Machine learning assisted screening of nitrogen-doped graphene-based dual-atom hydrogen evolution electrocatalysts

Nitrogen doped graphene-based dual-atom catalysts (NG-DACs) usually exhibit high reactivity for hydrogen evolution reaction (HER). The experimental design of efficient DACs-based HER catalysts, however, is time-consuming and expensive. In this work, a density functional theory combined with machine learning (DFT-ML) strategy is adopted towards the rapid screening of NG-DACs HER catalyst. The adsorption energies of HER intermediates on NG-DACs obtained by DFT calculations and their elemental features were used for the ML database construction. The prediction performance of three ML algorithms was evaluated, and gradient boosted regression (GBR) is found exhibit the best prediction accuracy. Using the HER energetics on Pt (111) as reference, quick screening of the NG-DACs with high HER activity was achieved, resulting to twenty-four potential catalysts. Further selection and validation of the ML-screened catalysts were performed by the hydrogen adsorption Gibbs free energy analysis. Accordingly, four promising NG-DACs HER catalysts were predicted using the proposed DFT-ML based catalyst prediction framework. The DFT-ML strategy offers an promising approach for the screening of new HER electrocatalysts.

Enhancing solar-driven hydrogen production through photoelectrochemical methods via dual transition metal doping of titanium oxide to form an impurity energy band

Developing a photoanode that is stable, efficient, and cost-effective for photoelectrochemical water splitting poses a significant challenge. To address this, we have successfully synthesized cobalt and chromium-doped Titanium dioxide (CoCrTiO2) using the hydrothermal method. This innovative approach results in an efficient, stable, and economical material. The introduction of Co and Cr through doping creates an intermediate band energy within TiO2, thereby enhancing charge separation and movement. The performance of CoCrTiO2 in the photoelectrochemical water splitting process is noteworthy. At 0 V vs Ag/AgCl, CoCrTiO2 exhibits a photocurrent density of 3.45 mAcm−2, representing an impressive 8.5 times increase compared to bare TiO2. Furthermore, when employed as a photoanode, CoCrTiO2 demonstrates a significant increase in hydrogen production. The amount of hydrogen generated is measured at 67.8 μmolecm−2, surpassing bare TiO2 by a factor of 5.6. Analysis data strongly supports CoCrTiO2 as an excellent candidate for advancing the field of photoelectrochemical water splitting due to its exceptional performance characteristics.

Remote Sensing Data Assimilation to Improve the Seasonal Snow Cover Simulations Over the Heihe River Basin, Northwest China

ABSTRACTThe reliability of seasonal snow cover information is constrained by limitation of in situ observations and uncertainties in remote sensing data and model simulations in alpine region, thus posing important challenges to understanding the climate system and water resource management in alpine region. Here, the assimilation of daily cloud‐free Moderate Resolution Imaging Spectroradiometer (MODIS) normalised difference snow index (NDSI) product into an intermediate complexity snow mass and energy balance model—Flexible Snow Model (version FSM2_MO)—was implemented. The aim is to improve the model simulations of seasonal snow cover (snow‐covered extent; SCE, snow depth; SD, snow water equivalent; SWE, and snowmelt runoff; SMR) in the alpine region (a case of the upper‐middle reaches of the Heihe River basin, Northwest China). The results indicate comprehensive improvement in the simulation of SCE, SD, and SMR in the study area through data assimilation, with the ability to significantly reduce prior biases of the FSM2_MO. Based on the independent daily cloud‐free Advanced Very High Resolution Radiometer (AVHRR) SCE product, the updated SCE simulation (i.e., data assimilation) showed a reduction in mean absolute error (MAE) from 10.46% to 7.16%, root mean square error (RMSE) from 16.14% to 12.26%, and an increase in Pearson's correlation coefficient (CC) from 0.18 to 0.67 compared with the open loop simulation (i.e., without assimilation). The evaluation results of SD observation data showed that data assimilation improved SD simulation compared with the open loop run (OL). And utilising the monthly discharge observations at the Yingluoxia hydrological station, data assimilation slightly improved the SMR simulation. The updated SMR simulation achieved a CC of 0.91, Nash‐Sutcliffe efficiency coefficient (NSE) of 0.73, and Kling‐Gupta efficiency coefficient (KGE) of 0.76. Moreover, the Landsat 8‐derived snow cover map and Sentinel‐1‐derived SD also indicated that the updated simulation effectively filled in the missing snow cover and removed the superfluous snow cover predicted by the OL simulation in terms of spatial distribution.

Holmium ions influence in structural and optical properties of Aluminium Strontium-phosphate glasses for radiation shielding applications

This study details the synthesis of a novel series of Holmium-doped Aluminium Strontium-phosphate glass (HoAlSr- phosphate glass) composed of 55 P2O5 + 5 Al2O3 + 4 MgO + 5 NaF + 10 LiCO3 + 5 CaO + 10 SrCO3 + 5 ZnO + 1 Ho2O3 prepared by melt-quench method and its structural, optical, and physical properties are analysed. Powder −XRD verified its amorphous nature, FTIR shows the existence of large phosphate functional groups, Optical properties such as band gap energy was calculated by acquiring absorption spectra covering the UV, Vis, and NIR ranges. Obtained 3.02 eV optical band gap energy. The refractive index changing with increasing energy. Three peaks in the PL spectra corresponded to Ho3+ transitions: 5I8→ 5G6, 5I8→ 3K8, and 5I8→ 5F3. The glass conducted theoretical studies for radiation shielding properties based on several key parameters. Gamma radiation shielding parameters, including Mean Free path (MFP), Effective atomic number (Zeff), linear attenuation coefficient (LAC), and mass attenuation coefficient (MAC), were obtained with the use of the Phy-X program. MAC data show that when Compton scattering (CS) fluctuates in the intermediate photon energy zone (E > 3 MeV), the area of prominence of CS diminishes. They can cause pair production at higher energies, Compton scattering at intermediate energies, and the photoelectric effect at lower energies. The MFP values of glasses doped with HoAlSr- phosphate glass were shorter, indicating a higher level of shielding efficacy. In this study we are focusing on optical properties changes with presence of Holmium ions and its shielding property using Phy-x software. In this research discovered that the synthetic material has high shielding qualities and can be a valuable shield in environments where X-rays are present. So it will be beneficial at X-ray prompted environment

Extrinsic tungsten doping to improve the intrinsic electrocatalytic activity of NiBP spheres for overall water splitting under high current density operation

Extrinsic heteroatom doping is an effective approach to enhance the electrochemical performance of electrocatalysts by the creation of new active sites, improved conductivity and optimization of adsorption/desorption energies. In this study, a W-doped NiBP electrocatalyst is designed by using hydrothermal synthesis and soaking doping approach for overall water splitting application. The W-doped NiBP spheres exhibit the overpotentials of 260 and 380 mV at 500 mA/cm2 in 1 M KOH for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) respectively. The bifunctional W-doped NiBP electrode demonstrates superior 2-E water splitting efficiency, requiring a low cell voltage of only 2.66 V at the high current density (HCD) of 2,000 mA/cm2, significantly surpassing the benchmark Pt/C||RuO2 system. Additionally, it exhibits good stability with the continuous 120 hrs of water splitting operation without noticeable degradation. A hybrid Pt/C||W-doped NiBP demonstrates a further reduced voltage of 2.54 V at 2,000 mA/cm2.The substantial performance enhancement can be attributed to the increased active sites, enhanced conductivity and optimized adsorption/desorption energies of intermediates through tungsten heteroatom doping.

Efficient electrocatalytic oxygen evolution enabled by porous Eu-Ni(PO3)2 nanosheet arrays

Phosphorous compounds have garnered significant interest as catalysts for the oxygen evolution reaction (OER). However, their catalytic performance often falls short, limiting their widespread application in electrocatalysis. The objective of this work is to improve the OER performance of nickel metaphosphate (Ni(PO3)2) by incorporating rare-earth europium (Eu). The prepared Eu-Ni(PO3)2 exhibits significant electron redistribution and features porous nanosheet arrays. The optimized Eu-Ni(PO3)2 exhibits outstanding OER activity, with an overpotential of 273 mV at 10 mA/cm, rapid OER kinetics with a Tafel slope of 39.4 mV/dec, and excellent electrochemical stability. These results surpass the performance of Ni(PO3)2, many reported Ni-based catalysts, and even commercial RuO2. Operando Raman spectroscopy reveals that the improvement of OER performance on Eu-Ni(PO3)2 is due to the accelerated formation of surface NiOOH active species and the enhanced interfacial water enrichment during OER. Density functional theory (DFT) calculations further demonstrate that Eu doping induces electronic modulation between the Eu sites and adjacent O-Ni sites, resulting in an optimized thermodynamic pathway with balanced adsorption energies for key oxygen intermediates, thus alleviating thermodynamic limitations during OER.

Reaction mechanism of pyridine radicals with molecular oxygen: A theoretical study

Pyridine is a suitable surrogate of the fuel-nitrogen in flame studies. The goal of the present work was to extend the analysis of reactions of pyridyl radicals with O2. All reactions proceed following similar mechanisms, through the barrier-free addition of an O2 molecule and further development along two main paths: through barrier-free abstraction of an oxygen atom and through the formation of a seven-membered ring. The energies of the main intermediates of all three reactions, calculated relative to the pyridyl + O2 system, have similar values. All three reactions are characterized by the formation of 1λ2-pyrrole, as well as HCO, HCN, C2H2 and CO.

Bond engineering: weakening Ru–O covalency for efficient and stable water oxidation in acidic solutions

The persistent stability of ruthenium dioxide (RuO2) in acidic oxygen evolution reactions (OER) is compromised by the involvement of lattice oxygen (LO) and metal dissolution during the OER process. Heteroatom doping has been recognized as a viable strategy to foster the stability of RuO2 for acidic OER applications. This study presented an ion that does not readily gain or lose electrons, Ba2+, into RuO2 (Ba–RuO2) nanosheet (NS) catalyst that increased the number of exposed active sites, achieving a current density of 10 mA/cm2 with an overpotential of only 229 mV and sustaining this output for over 250 h. According to density functional theory (DFT) and X-ray absorption spectroscopy, Ba doping resulted in a longer Ru–O bond length, which in turn diminished the covalency of the bond. This alteration curtailed the involvement of LO and the dissolution of ruthenium (Ru), thereby markedly improving the durability of the catalyst over extended periods. Additionally, attenuated total reflectance-surface enhanced infrared absorption spectroscopy analysis substantiated that the OER mechanism shifted from a LO-mediated pathway to an adsorbate evolution pathway due to Ba doping, thereby circumventing Ru over-oxidation and further enhancing the stability of RuO2. Furthermore, DFT findings uncovered that Ba doping optimizes the adsorption energy of intermediates, thus enhancing the OER activity in acidic environments. This study offers a potent strategy to guide future developments on Ru-based oxide catalysts’ stability in an acidic environment.

Highly enhanced photocatalytic performance for CO2 reduction on NH2-MIL-125(Ti): The impact of (Cu, Mn) co-incorporation

Photocatalytic CO2 reduction has been considered as an efficient way for the carbon nuetrality. In this work, a series of (Cu, Mn) co-incorporated metal-orgnaic frameworks (MOFs) (NH2-MIL-125(Ti) (NML)) with different Cu2+/Ti4+ and Mn2+/Ti4+ molar ratios are systematically investigated to improve the efficiency for photocatalytic CO2 reduction. The optimized sample (1 M−5C−−NML) shows a highest yield of HCOOH (116.74 μmol.g−1.h−1) (3.71 times higher than that of NML), and a superior apparent quantum efficiency (AQE) (6.74 % at 405 nm). The improved performance is attributed to the formed oxygen vacancy and intermediate energy level as introduced by the co-incorporation, which facilitate the charge separation and enhance the visible-light-harvesting of NML. It shows that the density of oxygen vacancies increases with the increasing amount of Cu, resulting in enhanced charge separation. However, the increasing amount of Mn leads to the short-range Mn-Mn interaction, the concentration quenching effect as well as the inhibited photocatalytic performance. This work shows that the co-incorporated MOFs can be used as an advanced photocatalyst.

FAZIA: a new generation array for nuclear dynamics and EoS experiments at intermediate energies

FAZIA: a new generation array for nuclear dynamics and EoS experiments at intermediate energies

Active Site Customizing of Metal-Organic Materials for Highly Efficient Oxygen Evolution.

Elucidating the correlation of active sites and catalytic activity in multi-component metal-organic frameworks (MOFs) is key to understanding the mechanism of oxygen evolution reaction (OER), yet it remains nebulous. Herein, a direct pathway combining theoretical prediction with anchoring high-valence metals is proposed on MOFs to reveal the mechanism of the OER reaction. Density functional theory (DFT) predicts that the co-modulation by Mo and Co atoms can enhance the conductance of CoMOF and optimize the adsorption-free energies of the OER intermediates. Guided by the theoretical prediction, the Co-based MOFs grown on Ni foams are doped with high valence Mo, which is used as model catalysts for the quantitative study of the composition-dependent OER performance. With Co/Mo in the ratio of 5:1 for the highest OER activity (impressively overpotential of 324mV at 100mA cm-2 and a Tafel slope of 96.07mV dec-1) and excellent stability (maintains for 200h at 100mA cm-2), the catalysts in this work is superior to commercial benchmarks electrocatalysts (RuO2/NF, 420mV, 199.12mV dec-1). This work sheds light on the tailoring of the active sites of MOFs, which is highly correlated with the activity of the OER.

Rigid Ligand Confined Synthesis of Carbon Supported Dimeric Fe Sites with High-Performance Oxygen Reduction Reaction Activity for Quasi-Solid-State Rechargeable Zn-Air Batteries.

Dimeric metal sites (DiMSs) in carbon-based single atom catalysts (SACs) offer distinct advantages in optimizing the adsorption energies of the catalytic intermediates and reaction pathways over single atom sites, which inspires the investigations on the rational design of DiMSs-based SACs and the accurate discernment of catalytic mechanisms. Here, dimeric Fe sites on carbon blacks (DiFe-N/CBs) are prepared using the precursor of metal-organic complex with a controlled structure, and the rigid ligand confinement secures the preservation of dimeric Fe sites during the thermal treatment. DiFe-N/CBs shows excellent electrocatalytic performance for oxygen reduction reaction (ORR) with a high half-wave potential of 0.917 V, and excellent durability with negligible activity decay. Theoretical studies reveal that the dimeric Fe sites have an optimal adsorption of OOH* with the Yeager-type binding, illustrating the advantages of DiMSs over SAs in catalyzing ORR. The rechargeable aqueous and quasi-solid-state Zn-air batteries assembled using DiFe-N/CBs-based air cathodes achieve small voltage gaps after long term charge/discharge test, showing great promises for practical applications. This synthetic strategy serves a novel platform to produce a scope of catalysts incorporating multimeric metal sites, and studies on the catalytic mechanism lay the foundation for establishing cooperative effect for multidentate adsorption reactions.

Rigid Ligand Confined Synthesis of Carbon Supported Dimeric Fe Sites with High‐Performance Oxygen Reduction Reaction Activity for Quasi‐Solid‐State Rechargeable Zn‐Air Batteries

AbstractDimeric metal sites (DiMSs) in carbon‐based single atom catalysts (SACs) offer distinct advantages in optimizing the adsorption energies of the catalytic intermediates and reaction pathways over single atom sites, which inspires the investigations on the rational design of DiMSs‐based SACs and the accurate discernment of catalytic mechanisms. Here, dimeric Fe sites on carbon blacks (DiFe‐N/CBs) are prepared using the precursor of metal‐organic complex with a controlled structure, and the rigid ligand confinement secures the preservation of dimeric Fe sites during the thermal treatment. DiFe‐N/CBs shows excellent electrocatalytic performance for oxygen reduction reaction (ORR) with a high half‐wave potential of 0.917 V, and excellent durability with negligible activity decay. Theoretical studies reveal that the dimeric Fe sites have an optimal adsorption of OOH* with the Yeager‐type binding, illustrating the advantages of DiMSs over SAs in catalyzing ORR. The rechargeable aqueous and quasi‐solid‐state Zn‐air batteries assembled using DiFe‐N/CBs‐based air cathodes achieve small voltage gaps after long term charge/discharge test, showing great promises for practical applications. This synthetic strategy serves a novel platform to produce a scope of catalysts incorporating multimeric metal sites, and studies on the catalytic mechanism lay the foundation for establishing cooperative effect for multidentate adsorption reactions.