Enhanced Oxygen Evolution Reaction Performance Research Articles

Activation of Hidden Catalytic Sites in 2D Basal Plane via p–n Heterojunction Interface Engineering Toward Efficient Oxygen Evolution Reaction

AbstractNonprecious metal‐based 2D materials have shown promising electrocatalytic activity toward the oxygen evolution reaction (OER). However, the catalytically active sites of 2D materials are mainly presented at the edge, and most of their basal planes are still catalytically inactive, which turns into a significant drawback on the catalytic efficiency. Here, a novel p–n heterojunction strategy is suggested that generates active sites on the basal plane of 2D NiFe‐layered double hydroxide (NiFe‐LDH). The n‐type NiFe‐LDH is first grown on a nickel foam (NF) substrate, and p‐type Co3O4 nanocubes are deposited through a simple dip‐coating method to fabricate a Co3O4/NiFe‐LDH@NF p–n heterojunction electrode. As a result, electron transfer is induced at the interface of p‐type Co3O4 and n‐type NiFe‐LDH, which consequently promotes oxidation of the inert Ni2+ state to a more catalytically active Ni3+ state on the inert basal plane of NiFe‐LDH. As‐prepared Co3O4/NiFe‐LDH@NF electrodes obtained enhanced OER performance showing a high current density of 100 mA cm−2 at 1.48 V (vs RHE) which outperforms that of pristine NiFe‐LDH@NF. The utilization of the p–n junction concept will disclose a new strategy for modifying the electronic structure of the catalytically inactive basal plane and stimulating its electrocatalytic activity.

Enhanced Oxygen Evolution Reaction Performance of NiMoO4/Carbon Paper Electrocatalysts in Anion Exchange Membrane Water Electrolysis by Atmospheric-Pressure Plasma Jet Treatment.

NiMoO4 was grown on carbon paper (CP) by a hydrothermal method. A rapid and high-temperature atmospheric-pressure plasma jet (APPJ) process was used to generate more oxygen-deficient NiMoO4 on the CP surface to serve as an electrode material for the oxygen evolution reaction (OER). After 60 s of APPJ treatment, the overpotential of the electrode at 100 mA/cm2 decreased to 790 mV and that at 10 mA/cm2 decreased to 368 mV. Additionally, the charge transfer resistance decreased from 2.8 to 1.2 Ω, indicating that APPJ treatment effectively reduced the electrode overpotential and impedance. The effect of NiMoO4/CP/APPJ-60 s on the anion exchange membrane water electrolysis (AEMWE) system was also tested. At a system temperature of 70 °C and current density of 100 mA/cm2, the energy efficiency reached 95.1%, and the specific energy consumption decreased from 4.02 to 3.83 kWh/m3. These results demonstrate that the APPJ-treated NiMoO4/CP electrode can effectively enhance the OER performance in water electrolysis and improve the energy efficiency of the AEMWE system. This approach shows promise in replacing precious metal electrodes, thereby potentially reducing the cost and providing an environmentally friendly alternative.

CoFe2O4 nanoparticle embedded carbon nanofibers: A promising non-noble metal catalyst for oxygen evolution reaction

There is a strong demand for noble metal-free durable catalysts to facilitate the advancement of clean, sustainable energy technologies and to replace energy equipment reliant on fossil fuels. In this study, metal-organic framework (MOF)-derived CoFe2O4 (CFO) nanoparticle-embedded electrospun carbon nanofibers (CNFs) were synthesized. Nanofibers were calcined at three different temperatures to obtain optimum electrocatalytic performance in oxygen evolution reaction (OER). Nanofibers annealed at 800 °C (CFO@CNFs 800) displayed a reduced overpotential of 300 mV while maintaining a steady current density of 10 mA cm−2. CFO@CNFs 800 demonstrated Tafel slope 42 mV dec−1 with excellent long-term stability up to 48 h. The synergistic effect of the redox activity of CFO coupled with the high surface area and conductivity of carbon nanofibers is responsible for enhanced OER performance.

Nanohybrids of B- and N-codoped reduced graphene oxide/CeO2–Co3O4 nanocomposite for efficient water oxidation

Transition metal oxides are well known as highly active and durable catalysts for the oxygen evolution reaction (OER). In this work, to enhance the electrocatalytic activity of CeO2 nanostructure in the water oxidation reaction, CeO2/Co3O4 and boron-nitrogen co-doped reduced graphene oxide incorporated (B,N-rGO) into CeO2/Co3O4 with a weight ratio of 3:1 of nanoparticles to graphene oxide were synthesized using co-precipitation and hydrothermal methods, respectively. The prepared materials were studied in detail regarding their crystal structure and morphological properties. The as-prepared materials were used as modified carbon paste electrodes for electrochemical water oxidation in an alkaline solution. The results showed that incorporating graphene oxide network into the nanoparticles structure enhances their OER performance. The material based on CeO2/Co3O4@B,N-rGO hybrid nanocomposite showed excellent OER activity with an overpotential of 410@10 mA cm−2, which is 240 and 140 mV less than that of the single CeO2 and CeO2/Co3O4 samples. Also, CeO2/Co3O4@B,N-rGO displayed the lowest Tafel slope and charge transfer resistance among the other catalysts. Moreover, the proposed catalyst displayed high stability and durability during OER. The enhanced OER performance of the CeO2/Co3O4@B,N-rGO is attributed to several catalytically active sites created by B and N doped rGO in the nanocomposite structure. The high performance of this catalyst results from the synergy of combining CeO2/Co3O4 nanoparticles with a three-dimensional co-doped rGO network.

Oxygen evolution over Fe1/NiSe2 single-atom electrocatalyst: The role of thermal-electrical cascade and surface reconstruing

Oxygen evolution reaction (OER) in water electrolysis is a tough challenge. Here we report the thermally activated on-surface oxygen evolution at nickel diselenide under alkaline conditions, specifically focusing on the (101) and (100) facets supported with Fe single-atom electrocatalysts. Assisted by heat, the Fe1/NiSe2(101) and (100) facets demonstrate highly efficient activity for oxygen evolution at pH = 14. First-principles calculations and AIMD simulations illustrate excellent electrical conductivity and thermal stability of the Fe1/NiSe2(101) and (100) facets, as well as provide a promising understanding of electron transports among the oxygen-containing active species and the electrocatalysts during thermal-electrical cascade of OER under alkaline conditions. The enhanced OER performance depends on the co-adsorbate combinations: *O(Fe-SeⅠ)-*OH(SeⅡ) and *O(Fe-SeⅠ)-*OH(Ni) at the Fe1/NiSe2(101) facet, whose adsorption behaviors lead to self-activated surface reconstruing. Impressively, the affinity of the key intermediates at the potential-determining steps of OER: *O(Fe-SeⅠ) at the Fe1/NiSe2(101) facet, *O(Fe) and *OOH(Fe) at the Fe1/NiSe2(100) facet, is optimized by such self-activated surface reconstruing.

Tailoring Ni-Fe-B Electronic Effects in Layered Double Hydroxides for Enhanced Oxygen Evolution Activity.

NiFe layered double hydroxides (LDHs) are state-of-the-art catalysts for the oxygen evolution reaction (OER) in alkaline media, yet they still face significant overpotentials. Here, quantitative boron (B) doping is introduced in NiFe LDHs (ranging from 0% to 20.3%) to effectively tailor the Ni-Fe-B electronic interactions for enhanced OER performance. The co-hydrolysis synthesis approach synchronizes the hydrolysis rates of Ni and Fe precursors with the formation rate of B─O─M (M: Ni, Fe) bonds, ensuring precise B doping into the NiFe LDHs. It is demonstrated that B, as an electron-deficient element, acts as an "electron sink" at doping levels from 0% to 13.5%, facilitating the transition of Ni2+ to the active Ni3+δ, thereby accelerating OER kinetics. However, excessive B doping (13.5-20.3%) effectively generates oxygen vacancies in the LDHs, which increases electron density at Ni2+ sites and hinders their transition to Ni3+δ, thereby reducing OER activity. Optimal OER performance is achieved at a B doping level of 13.5%, with an overpotential of only 208mV to reach a current density of 500mA cm-2, placing it among the most effective OER catalysts to date. This Ni-Fe-B electronic engineering opens new avenues for developing highly efficient anode catalysts for water-splitting hydrogen production.

Boosting Oxygen Evolution Reaction Performance on NiFe-Based Catalysts Through d-Orbital Hybridization

HighlightsThe NiFeLa catalyst with 3d-5d orbital coupling exhibits remarkable oxygen evolution reaction (OER) activity and stability, enabling an anion-exchange membrane water electrolyzers device to achieve a cell voltage of only 1.58 V at 1 A cm−2 as well as long-term stability over 600 h.The introduction of La disrupts the symmetry of Ni-Fe units and optimize d band center, which affects the d-p orbital hybridization between the metal sites on the surface of the catalyst and oxygen-containing intermediates during the OER process.The 5d-introduced NiFeLa has enhanced adsorption strength of oxygen intermediates, which can reduce the rate-determining step energy barrier and prevent catalyst dissolution.

Enhanced oxygen evolution reaction performance using amorphous hollow cerium-doped cobalt phosphate derived from ZIF-67 structures

A major obstacle in achieving massive operations water splitting is the slow rate of the anodic reaction. To address this issue, metal phosphates have been extensively employed as efficient materials for the oxygen evolution reaction (OER). In this study, ZIF-67 structures were synthesized in both single-metal and bimetallic forms with different molar ratios of cerium. The structure with the best electrochemical activity ((5 present) cerium doped ZIF-67 ((5)CeZIF-67)) was subjected to a phosphatization process, resulting in the formation of the amorphous and hollow cerium doped cobalt phosphate (Ce-CPO) structure as a novel and highly efficient OER electrocatalyst. To the best of authors knowledge, this is the first report on the synthesis and application of Ce-CPO structure for boosting OER process. This resultant structure exhibited suitable electrochemical performance in the oxygen evolution reaction (OER), achieving an overpotential of 286 mV at a current density of 30 mA cm−2 and a Tafel slope of 74.4 mV decade−1. Furthermore, the final structure demonstrated satisfactory stability during a 10 h operation period. The notable improvement in the Ce-CPO structure was due to the use of a bimetallic framework combined with phosphorus and an amorphous porous structure. The distinctive configuration achieved greatly amplifies the effective surface area, hence improving electron transfer. The findings of this research can contribute to the development of electrodes with improved performance in OER.

Efficient electrocatalysts for OER: Amorphous cerium-doped cobalt sulfide with enhanced performance and durability

Developing highly efficient electrocatalysts is essential for advancing the oxygen evolution reaction (OER), a key step in water splitting. In this study, a novel approach for the synthesis of an amorphous sulfide structure has been presented. First, a cerium-doped zeolitic imidazolate framework-67 (Ce-ZIF-67) using a co-precipitation method, followed by a multi-step transformation process. This process includes oxidation to form cerium-doped cobalt oxide (Ce-CO) and a subsequent sulfidation step to produce an amorphous cerium-doped cobalt sulfide (Ce-CS) structure. The introduction of cerium and the formation of an amorphous sulfide structure result in a significantly enhanced OER performance due to increased atomic disorder, improved electron mobility, and an expanded active surface area. Remarkably, the Ce-CS structure achieved a reduction in overpotential from 352 mV for Ce-CO to 291 mV at 100 mA cm−2 in 1.0 M KOH, alongside a Tafel slope reduction from 86.2 mA decade−1 to 67.2 mV decade−1. These enhancements underline the importance of cerium doping and amorphization in optimizing electrocatalytic efficiency. Furthermore, the Ce-CS catalyst demonstrated exceptional durability, with no observable degradation in performance or structural integrity after 10 h of continuous operation. This work presents a pioneering strategy for designing and synthesizing highly effective OER electrocatalysts, contributing a significant advancement to the field.

Surface Reconstruction Regulation of Co3N Through Heterostructure Engineering Toward Efficient Oxygen Evolution Reaction.

Oxygen evolution reaction (OER) electrocatalysts generally experience structural and electronic modifications during electrocatalysis. This phenomenon, referred to as surface reconstruction, results in the formation of catalytically active species that act as real OER sites. Controlling surface reconstruction therefore is vital for enhancing the OER performance of electrocatalysts. In this study, a new approach is introduced of heterostructure engineering to facilitate the surface reconstruction of target catalysts. Using MnCo carbonate hydroxide (MnCo─CH)@Co3N as a demonstration, it is discovered that the surface reconstruction occurs more readily and rapidly on MnCo─CH@Co3N than on Co3N. More interestingly, during the reconstruction process, Mn species migrate to the surface, enabling the in situ formation of highly active Mn-doped CoOOH. Consequently, the MnCo─CH@Co3N catalyst after reconstruction exhibits a low overpotential of 257mV at 10mAcm-2, compared to 379mV of individual Co3N. This work offers fresh perspectives on understanding the enhanced OER performance of heterostructure electrocatalysts and the role of heterostructure in promoting surface reconstruction.

Facilitating the rapid Grotthuss diffusion of OH− in electrolyte for accelerated oxygen evolution reaction

Faster OH− transfer for efficient adsorption on catalysis is key to accelerating the oxygen evolution reaction (OER). The diffusion of OH− in electrolyte mainly involves two mechanism which is dependent on the water coordination number (CN): Grotthuss diffusion (4 CN) and vehicular diffusion (5 CN). The Grotthuss diffusion is much faster but the vehicular diffusion of OH− is predominant in the electrolyte. Herein, negatively charged kaolin, which are simply dispersed in the electrolyte, are utilized to provide surface electrostatic attraction to H2O and repulsion to OH− to reduce the OH− CN from 5 to 4 for rapid Grotthuss diffusion. This contributes to the accelerated OH− adsorption which facilitates the charge transfer, the formation and the deprotonation of *OOH leading to enhanced OER performance. The OH− CN recovery from 4 to 5 is proved quite slow after leaving the kaolin surface, breaking the limitation that kaolin must be on the catalyst surface. This strategy exhibits universality for various electrocatalysts with reduced overpotential by 10–246 mV at 10 mA cm−2. We provide a clean, simple and low-cost way to promote the industrial development of alkaline water electrolysis.

Investigating the Role of Mixed Oxides for Oxygen Evolution Reaction on Iridium Oxide Electrocatalysts

Ongoing concerns over anthropogenic emissions, fossil fuel sustainability, and related geopolitical aspects point to an increasing need for cost-effective renewable fuel sources. A promising solution is the generation of hydrogen via the catalytic splitting of water, which can be achieved with the aid of proton exchange membrane (PEM) electrolyzers. Notably, the anode material in current commercially available PEM electrolyzers is typically iridium oxide. Despite its effectiveness in facilitating the oxygen evolution reaction (OER), the use of iridium oxide poses challenges due to the scarcity and high cost associated with this precious metal. As the quest for sustainable energy intensifies, ongoing research explores innovative approaches, such as the incorporation of alternative materials and catalysts, to enhance efficiency while addressing the economic and environmental concerns associated with iridium oxide. Studies have shown that incorporating mixed oxides and switching the supports for iridium oxide catalysts help lower the iridium loading while enhancing the OER performance.1,2 In this study, we investigate a series of different sputtered, mixed iridium oxides (Ta, Ti, Ir). We use a rotating disk electrode system to benchmark the catalytic activity of different loadings of mixed oxides. To measure the intrinsic activity of each catalytic active site, we use a home-built operando UV-Vis system to quantify the populations of surface species as well as track the kinetics of different redox transitions during OER. We incorporate nanoscale secondary ion mass spectrometry to probe the migration of different mixed oxide species before and after electrochemical cycling and use kelvin probe force microscopy to estimate the conductivity through the different films. In this study, we show the importance of cooperative effects between neighboring iridium oxide species and the coordination of iridium that are responsible for enhanced OER performance. These results indicate that doping modulates coverage dependent interactions at the surface, which affects both the binding energetics and populations of rate limiting intermediates. We believe this study will serve as a steppingstone for future designs of more cost-efficient PEM electrolyzers.(1) Oh, Hyung-Suk, et al. "Electrochemical catalyst–support effects and their stabilizing role for IrO x nanoparticle catalysts during the oxygen evolution reaction." Journal of the American Chemical Society 138.38 (2016): 12552-12563.(2) Zheng, Ya-Rong, et al. "Monitoring oxygen production on mass-selected iridium–tantalum oxide electrocatalysts." Nature Energy 7.1 (2022): 55-64.

Photoluminescence, cytotoxic and oxygen evolution reaction kinetics studies of silver doped haematite nanoparticles

Fe2O3: Ag(1–9 mol %) nanoparticles (NPs) have been synthesized through the co-precipitation method. Crystallite size, phase, crystallinity, and structural parameters were analyzed by using powder X-ray diffraction. The Bragg reflections confirm that the synthesized NPs crystallize in hexagonal crystal structure with space group R-3c. Surface morphology consists of agglomerated irregular size and roughly spherical-shaped NPs. Energy Dispersive Analysis of X-ray confirms the presence of Fe, O, and Ag elements and also the purity of the sample. Crystallite size decreased with the increase in dopant concentration. Direct band gap energy is found to increase with an increase in dopant concentration. Photoluminescence and anticancer properties were studied in detail. The CIE coordinates confirm red emission in the visible region. CIE and CCT co-ordinate values indicate cool light emission, hence, the synthesized nanophosphor material meets the demand of display technology. Further anticancer properties were investigated on HeLa cells and compared with the standard drug cisplatin for biomedical applications. Further, Oxygen evolution reaction kinetics was investigated for Fe2O3:Ag (1 mol %) nanoparticles. demonstrates enhanced oxygen evolution reaction performance with a low overpotential of 348 mV, as shown by linear sweep voltammetry. It also exhibits a favorable Tafel slope of 83 mV/dec, indicating efficient electron transfer kinetics, making it a promising candidate for OER applications.

Magnesium-promoted rapid self-reconstruction of NiFe-based electrocatalysts toward efficient oxygen evolution

The acceleration of active sites formation through surface reconstruction is widely acknowledged as the crucial factor in developing high-performance oxygen evolution reaction (OER) catalysts for water splitting. Herein, a simple one-step corrosion method and magnesium (Mg)-promoted strategy are reported to develop the NiFe-based catalyst with enhanced OER performance. The Mg is introduced in NiFe materials to preparate a “pre-catalyst” Mg-Ni/Fe2O3. In-situ Raman shows that Mg doping would accelerate the self-reconstruction of Ni/Fe2O3 to form active NiOOH species during OER. In-situ infrared indicates that Mg doping benefits the formation of *OOH intermediate. Theoretical analysis further confirms that Mg doping can optimize the adsorption of oxygen intermediates, accelerating the OER kinetics. Accordingly, the Mg-Ni/Fe2O3 catalyst exhibits excellent OER performance with overpotential of 168 mV at 10 mA cm−2. The anion exchange membrane water electrolyzer achieved 200 mA cm−2 at voltage of 1.53 V, showing excellent stability over 500 h as well. This work demonstrates the potential of Mg-promoted strategy in regulating the activity of transition metal-based OER electrocatalysts.

Promoted surface reconstruction of pentlandite via phosphorus-doping for enhanced oxygen evolution reaction

The pentlandite Fe5Ni4S8(abbreviated as FNS) is not efficient for water splitting because of its inferior performance for the oxygen evolution reaction (OER). This issue originates from the low activity and instability of FNS during the OER process but can be solved through appropriate doping. Herein, a P-doping strategy based on annealing in the presence of NaH2PO2as a phosphorus source upstream was employed on FNS to enhance its activity and stability toward OER. The results demonstrated fine-tuned electronic structures of Fe and Ni in FNS through P-doping, resulting in suppressed Fe leaching,improved electrical conductivity of FNS, and easier formation of NiOOH on the surface of the catalyst. In turn, these features enhanced the OER activity and stability. The optimal P-doped FNS catalyst FNSP-40 exhibited a 4-fold greater electrochemical surface area compared to that of FNS, accompanied by an overpotential of 235 mV at 10 mA cm−2. The optimized FNSP-40 catalyst was used as an anode, and platinum-decorated FNS was used as a cathode. This combination demonstrated an electrolysis performance with a cell voltage of 1.57 V, reaching a current density of 100 mA cm−2,which indicates efficient operation. The advantages of P-doping engineering were also verified in simulated seawater with enhanced OER performance. Overall, the proposed strategy looks promising for the fabrication of pentlandite-structured catalysts for efficient alkaline water and seawater oxidation.

Enhanced Oxygen Evolution Reaction Performance in Co–Fe Hydroxides through Boron Doping

Among hydrogen production methods, water electrolysis stands out, but its efficiency is hampered by the substantial energy barrier of the oxygen evolution reaction (OER). To address this, incorporating electron‐deficient boron (B) into Co–Fe hydroxide (CoFeOxHy) promotes higher oxidation states of involved metals, greatly enhancing OER activity and charge transfer capabilities. Herein, the synthesis of a range of amorphous CoFeB nanoparticles with varying Fe to (Co+Fe) atomic ratios achieved through a simple chemical reduction method using CoFe‐Prussian blue analogs as precursors and employing Mössbauer spectroscopy to observe structural characteristics before and after transformation is reported. Among these nanoparticles, the CoFe0.25B variant, exhibiting favorable electrochemical properties, is chosen and subsequently subjected to hydrolysis to yield CoFe0.25BOH nanoparticles, serving as an active catalyst for OER. At a current density of 10 mA cm−2, the overpotentials for CoFe0.25OxHy and CoFe0.25BOH are 362 and 310 mV, respectively, with Tafel slopes decreasing from 393 to 93 mV dec−1. Furthermore, the i–t test reveals no significant loss of electrochemical performance within 24 h, substantiating the efficacy of enhancing the electrocatalytic performance of CoFeOxHy through the introduction of electron‐deficient elements. This research offers novel insights into the development of efficient and stable water electrolysis catalysts.

Enhanced oxygen evolution reaction performance of nitrogen-doped carbon dots sensitized with rare-earth metal nanorods

An affordable, sustainable, effective, and strong catalyst for oxygen evolution reaction (OER) processes has gained increased significance because of its crucial role in energy conversion and storage. Heteroatom-doped amorphous carbon materials made from biomass have lately come into prominence as inexpensive, environmentally benign, renewable, and sustainable materials. Substantial research about the incredible performance in OER by carbon dots has been devoted, yet durability remains a challenge. Therefore, we reported novel carbon dots doped with a heteroatom (nCDs) included with Gd(OH)3, a rare-earth hydroxide element. Taking advantage of numerous active and edge sites of CDs and modifying the chemistry of the surface by doping with foreign atoms, the prepared nCDs/Gd(OH)3 revealed the outstanding catalytic performance of a low overpotential of 280 mV at a Tafel slope of 127 mV/dec at 10 mA/cm2 in sluggish alkaline medium. Our findings supported the synergistic interaction between the doped heteroatom and its surface's maximal exposure of nCDs/Gd(OH)3 sites, facilitating the rapid transport of reactants and sufficient contact to enhance OER performance. This study will garner more attention in the context of producing sustainable energy and storing it effectively. For clean, green energy, combining carbon dots with rare earth metals is an emerging candidate for energy conversion. The alkaline electrolyzer will find it to be a promising electrocatalyst, especially in seawater medium.

Electronic structure tailoring of CuCo2O4 for boosting oxygen evolution reaction

Electronic structure tuning in metal oxides is a facile and effective strategy on boosting their catalytic oxygen evolution reaction (OER) performance. Here, we demonstrate the electronic structure tuning of CuCo2O4 by phosphorus (P) doping via in-situ diffusion method. The results suggest that due to more electrons transferred from P to the neighboring Co3+, the tuned Co is served as catalytic active sites for the enhanced OER performance. The synthesized P3.85-CCO/NF exhibits an overpotential of 250 mV at a current density of 10 mA cm−2, and a Tafel slope of 27 mV dec−1, which performs an enhanced OER activity than that of IrO2/NF. Moreover, the P3.85-CCO/NF presents stable electrochemical performances upon long-time running for 30 h. Thus, the electronic structure tuning strategy by in-situ P diffusion method emerges as an effective approach on enhancing the catalytic OER performance for metal oxide electrocatalysts.

Ce- and La-doped polymetallic layered double hydroxides for enhanced oxygen evolution reaction performance at high current density

Ce- and La-doped polymetallic layered double hydroxides for enhanced oxygen evolution reaction performance at high current density

Atomic rare earths activate direct O-O coupling in manganese oxide towards electrocatalytic oxygen evolution

Activating the efficient electron transfer in oxygen evolution reaction (OER) by tuning the oxygen (O) electronic states near the Fermi level is essential to break the linear scaling limitation of OER intermediates. Herein, we construct a series of rare earth (RE) single atoms on MnO2 nanosheets with modulated oxygen states by an effective and universal Ar plasma (P)-assisted strategy (P-RE SAs@MnO2, RE = Gd, La, Ce, Tm, and Lu) to investigate the origin of RE-enhanced OER performance. Taking P-Gd SAs@MnO2 as a representative, the atomically dispersed Gd atoms on MnO2 assist the construction of localized asymmetric [Gd−O−Mn] units, which induces electron accumulation at surrounding oxygen sites by introducing the polarized ionic Gd−O bond. As a result, the P-Gd SAs@MnO2 delivers impressive OER performance with low overpotential (281 mV@10 mA cm −2; ηj10), robust long-term stability, and optimized activation energy (Ea = 32.07 kJ mol−1 at ηj10), which are superior to RE-free MnO2, commercial RuO2, and most Mn-based catalysts. Similar enhanced OER performance can also be found for other P-RE SAs@MnO2 (RE = La, Ce, Tm, and Lu). X-ray absorption and in situ Raman spectroscopy unveil the preferred electron accumulation at Mn−O, promoting the formation of terminal MnIV=O intermediates in OER. Theoretical calculations demonstrate that the construction of [Gd−O−Mn] unit endows the surface lattice unsaturated O site with the labile property, which assists the direct formation of (O−O) dimer for circumventing the universal scaling relation applied by the formation of *OOH. This work opens up a new avenue for the design of transition metal oxides with modulated oxygen state to break the limitation of the adsorbate evolution mechanism during OER.