Oxygen Evolution Reaction Rate Research Articles

Synthesis and OER catalytic activity of quasi zeolitic imidazolate Framework-67 having two and three dimensional morphology

Zeolitic imidazolate framework-67 (ZIF-67), in two and three dimensional (2D/3D) morphologies have been synthesized at room temperature using different solvent media, and annealed at 350 and 920 °C to derive the modified ZIF-67 based catalysts. All the ZIF-67 based catalysts were characterized using powder X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, Scanning electron microscopy, Thermogravimetric analysis, N2 gas adsorption method, and Positron annihilation lifetime spectroscopy. It has been observed that catalytic activity of the ZIF-67 based catalysts towards oxygen evolution reaction (OER) depends on the morphology and annealing-induced modifications in active sites. Among different morphologies of as-synthesized ZIF-67, 2D ZIF-67 (nanosheet and disc like morphology) exhibits the best electrocatalytic activity in as-synthesized as well as in the annealed form in comparison to 3D ZIF-67 (rhombic dodecahedron) owing to their better electronic properties. All the types of ZIF-67 annealed at 920 °C show the lower Tafel slopes suggesting higher OER rate.

Inhibiting Photo-Oxidation and Enhancing Visible-Light-Driven Photocatalytic Water Oxidation over Covalent Organic Frameworks Through the Coordination of Cobalt with Bipyridine.

Photocatalytic water splitting using covalent organic frameworks (COFs) is a promising approach for harnessing solar energy. However, challenges such as slow kinetic dynamics in the photocatalytic oxygen evolution reaction (OER) and COFs' self-oxidation hinder its progress. In this study, an enamine-based COF coordinated is introduced with cobalt dichloride, CoCl2 (CoCl2-TpBPy). The coordination of cobalt ions with bipyridines in CoCl2-TpBPy enhances charge-carrier separation and migration, leading to effective photocatalytic OER. Under visible light irradiation, CoCl2-TpBPy achieves a notable OER rate of up to 1 mmol·g-1·h-1, surpassing the reported organic semiconductor analogs. Additionally, CoCl2-TpBPy shows minimal nitrogen evolution compared to TpBPy and ethanol-treated TpBPy (E-TpBPy), indicating cobalt plays a pivotal role in improving charge utilization and minimizing photo-oxidation. In situ X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) analyses revealed that Co(IV) species are key to the high OER efficiency. This work highlights Co(IV) species in the efficient OER and inhibiting photo-oxidation of CoCl2-TpBPy.

Simultaneous enhancement of charge transfer and surface catalysis through a polymetallic oxide cocatalyst on BiVO4 photoanodes for highly efficient and stable water oxidation

The rate-determining oxygen evolution reaction (OER) always limits the high-efficient conversion of solar energy to green hydrogen fuels through photoelectrocatalytic or photocatalytic water splitting. The high catalytic overpotential and the instability of catalytic center are commonly regarded as the primary factors contributing to the low rate of OER, remaining to be a challenge in the field of water splitting. Herein, a polymetallic oxide cocatalyst (Mo-MnOy/FeCoNiOx) with well-defined electronic and catalytic properties is designed on BiVO4 photoelectrode for highly efficient and stable photoelectrocatalytic water oxidation. The experimental characterization demonstrates that the dual-layer design of Mo-MnOy/FeCoNiOx can significantly optimizes the electronic property of MnOy and FeCoNiOx components, boosting the photogenerated charge transfer between Mo-MnOy/FeCoNiOx cocatalyst and BiVO4 photoelectrode. The density functional theory (DFT) simulation reveals that the Mo sites in Mo-MnOy layer can activate the neighboring surface Mn sites instead of directly serving as the catalytic center, thereby establishing these Mn sites as primary active centers for achieving stable OER. The developed Mo-MnOy/FeCoNiOx/BiVO4 photoelectrode exhibits a current density of 6.18 mA cm−2 with an excellent stability for 30 h at 1.23 VRHE under 1 sun irradiation, exhibiting the excellent activity and durability. This work sheds light on design of high-performance multiple-component water-oxidation cocatalyst on photoanode.

Fe doped Co9S8 nanoparticles embedded in N, S co-doped porous carbon as an efficient bifunctional electrocatalyst for rechargeable Zn-air batteries

Transition metal sulfides embedded in co-doped porous carbon materials with nitrogen and sulfur are a promising catalyst that can effectively solve the problem of slow oxygen reduction reaction (ORR) kinetics. However, monometallic sulfides consisting of a single active component only have monofunctional catalytic activity and cannot effectively increase the rate of oxygen evolution reaction (OER), thus limiting the energy conversion efficiency of Zn-air batteries (ZAB). Herein, a unique silica template assisted in situ pyrolysis strategy is used to synthesize iron (Fe)-doped cobalt sulfide (Co9S8) nanoparticle embedded in a honeycomb nitrogen (N), sulphur (S) co-doped porous carbon (Fe/Co9S8@NSC) electrocatalyst. The introduction of Fe increases the active component of the catalyst and further enhances the catalytic ability of Co9S8 by optimizing the electronic structure through charge transfer effect. Therefore, the rich active sites of Fe/Co9S8 nanoparticles anchored in N, S co-doped carbon materials with rich pore structure enable the catalysts to have good bifunctional catalytic activities of ORR and OER. In particular, the Fe/Co9S8@NSC has a high half-wave potential of 0.82 V for catalytic ORR and only needs low overpotential of 332 mV at a current density of 10 mA cm−2 for catalytic OER. In addition, the Fe/Co9S8@NSC catalyst based rechargeable ZAB also exhibits a significant specific capacity of 734 mAh g−1 and prolonged stability of 270 h, which outperforms the bulk of recently reported catalysts based on transition metal sulfides-based catalysts. This research offers a workable method for producing metal sulfides catalysts with bifunctional catalytic activity.

(Keynote) Kinetic and Non-Kinetic Limitations during Oxygen Evolution Reaction on Nickel-Iron Oxyhydroxide Electrodes

The rate and mechanism of the oxygen evolution reaction (OER) depends on many factors. Here, we show on the example of OER on nickel oxy-hydroxide electrodes in alkaline media, how the OER rate depends on pH, cations, nano-catalyst structure, bubble removal, mass transport, temperature and pressure. We illustrate that many of these parameters lead to a higher current (density) but also argue that they often do not actually remove true kinetic barriers. Tafel slope plots or differential Tafel plots are introduced as a powerful tool to separate kinetic from non-kinetic limitations.

Cobalt di-selenide embedded polymerised melamine paraformaldehyde resin: A robust and efficient electrocatalyst for OER with operando investigations

In past research metal selenides have reported versatile results in the field of water splitting. Cobalt di-selenide has received much attention in the oxygen evolution reaction (OER) due to its excellent results towards OER. To excel the reaction capability, herein we have reported CoSe2, pMF-R and CoSe2@pMF-R nanostructures in which the freshly prepared CoSe2 nanostructures were decorated on the surface of pMF-R (polymerised melamine paraformaldehyde resin). The study showed that the bonds between cobalt and nitrogen were well formed, which is maintaining the improved charge transfer channels to annihilate the barriers between the GC (glassy carbon) electrode surface and active sites of CoSe2. Because of the coaction of CoSe2 and pMF-R, the OER calibration of the CoSe2@pMF-R catalyst has shown a low onset potential 1.56 V and its electrochemical activity towards OER was found to be much higher as 10 mAcm−2 at 1.608 V Vs. RHE. Operando spectroelectrochemical investigations revealed that active sites of selenium, Co2+, Co3+ and pMF-R available for generation of intermediate oxygen species and responsible for exponential increase in rate of OER. The order of reaction is found to one. The compositional and structural characteristics of CoSe2@pMF-R composite over other electrocatalysts is responsible for outstanding electrochemical performance.

Unlocking the Potential of Amorphous Prussian Blue with Highly Active Mn Sites at Room Temperature for Impressive Oxygen Evolution Reaction and Super Capacitor Electrochemical Performance.

The key to increasing the rate of oxygen evolution reaction (OER) lies in accelerated four-electron dynamics, while the key to facilitating the development of supercapacitors lies in the design of electrode materials. This paper synthesized manganese-iron Prussian blue (MnFe-PBA@IF) at room temperature, and hexagonal concave structures w ere prepared using a fast-reducing matrix. Interestingly, MnFe-PBA@IF has an amorphous structure favorable to exposing more active surfaces. According to Gibbs free energy calculations on MnFe-PBA, charge depletion of manganese atoms can greatly enhance the adsorption of electron-rich oxygen-containing groups on the surface. Furthermore, the overpotential in 1 m KOH is 280 mV. Also, it can be used as a supercapacitor with a stable operating voltage range of -0.9-0 V and a specific capacity of 1260 Fg-1 . This work provides new insights into the synthesis of OER catalysts for Prussian blue ferromanganese at room temperature. Non-gold-bonded adsorption, highly active metal centers and active surfaces are the underlying reasons for the superior performance of supercapacitors. Therefore, Prussian blue with good energy storage performance and high active surface can be used as multifunctional energy storage and conversion electrodes.

Microwave‐Assisted Synthesis of Cobalt‐Based Selenides as Catalyst Precursors for the Alkaline Water Oxidation

When used to promote the oxygen evolution reaction (OER), transition‐metal chalcogenides convert into oxyhydroxide/(hydr)oxide catalysts, the performance of which depends on the properties of the precursor. The present study aims to explore these effects for cobalt and cobalt–iron selenides (CoSe n and Co1Fe1Se n ) prepared using a simple microwave‐assisted method, in comparison to a reference material synthesized by high‐temperature reaction of CoO x H y with Se vapors. Physical characterization of the microwave‐synthesized CoSe n demonstrates their sheet‐like morphology and identifies Co3Se4 as the major phase, which is essentially completely transformed into CoOOH during the OER. The temperature during the microwave‐assisted CoSe n synthesis affects the crystallinity, the electrochemically active surface area, and thereby the performance of the resulting catalysts. Further improvements in the activity are achieved by combining cobalt with iron into a bimetallic Co1Fe1Se n precursor, which transforms in situ into a CoOOH + FeOOH composite and sustains the OER rate of 100 mA cm−2 (33 A g−1) at an overpotential of ≈ 0.31 and 0.26 V at 24 ± 2 and 80 ± 1 °C, respectively. Satisfactory stability of the Co1Fe1Se n ‐derived electrodes is demonstrated through a 4‐day‐long test at 80 ± 1 °C and 100 mA cm−2.

Designing and regulating catalysts for enhanced oxygen evolution in acid electrolytes

AbstractThe proton exchange membrane (PEM) water electrolyzer has been considered a versatile approach for practical H2 production. However, the oxygen evolution reaction (OER) in acid media with complicated proton‐coupled electron transfer steps possesses sluggish kinetics and high reaction barriers, severely hindering the development of PEM water electrolyzers. Consequently, high‐efficient Ru‐ and Ir‐based catalysts have always been essential to accelerate the OER rate and lower the reaction barrier in PEM water electrolyzer. Therefore, it is very necessary to construct low‐cost catalysts with excellent electrocatalytic performances to replace these noble metal‐based OER electrocatalysts. In this review paper, a detailed discussion towards fundamentally comprehending the reaction mechanisms of OER was conducted. Accordingly, we proposed the principles of designing advanced OER electrocatalysts with enhanced performances and lowered costs. After that, recent developments in designing various acidic OER electrocatalysts were summarized. Meanwhile, the available regulation strategies about noble metals, nonprecious metals, and metal‐free nanomaterials were presented, which are promising for tuning the electronic structures, boosting the electrocatalytic performances, and reducing the costs of electrocatalysts. We also provided the existing challenges and perspectives of various OER electrocatalysts, hoping to promote the development of PEM water electrolyzers.

Strong-Proton-Adsorption Co-Based Electrocatalysts Achieve Active and Stable Neutral Seawater Splitting.

Direct electrolysis of pH-neutral seawater to generate hydrogen is an attractive approach for storing renewable energy. However, due to the anodic competition between the chlorine evolution and the oxygen evolution reaction (OER), direct seawater splitting suffers from a low current density and limited operating stability. Exploration of catalysts enabling an OER overpotential below the hypochlorite formation overpotential (≈490mV) is critical to suppress the chloride evolution and facilitate seawater splitting. Here, a proton-adsorption-promoting strategy to increase the OER rate is reported, resulting in a promoted and more stable neutral seawater splitting. The best catalysts herein are strong-proton-adsorption (SPA) materials such as palladium-doped cobalt oxide (Co3- x Pdx O4 ) catalysts. These achieve an OER overpotential of 370mV at 10mAcm-2 in pH-neutral simulated seawater, outperforming Co3 O4 by a margin of 70mV. Co3- x Pdx O4 catalysts provide stable catalytic performance for 450h at 200mAcm-2 and 20h at 1Acm-2 in neutral seawater. Experimental studies and theoretical calculations suggest that the incorporation of SPA cations accelerates the rate-determining water dissociation step in neutral OER pathway, and control studies rule out the provision of additional OER sites as a main factor herein.

Enhancement in the photoelectrochemical performance of BiVO4 photoanode with high (0 4 0) facet exposure

Morphology and geometrical dimensions play crucial roles in the photoelectrochemical (PEC) performance of bismuth vanadate (BiVO4) for water splitting. Decahedral BiVO4 was synthesized through a facile hydrothermal process, which exhibited superior charge injection efficiency to the nanoporous counterpart prepared by the traditional method. More importantly, the crystal size and facet proportion of BiVO4 decahedrons were facilely controlled. The charge separation efficiency can be significantly improved with a reduction in the crystal size and an increase in (040) facet exposure. A new method was developed for rate law analysis: illumination intensity-modulated oxygen evolution reaction rate versus open circuit potential difference, which suggested that the surface reaction kinetics was not affected by facet regulation. Furthermore, after decorating the FeOOH and NiOOH as dual oxygen evolution cocatalysts, an enhanced photocurrent density of 3.2mAcm-2 at 1.23V versus reversible hydrogen electrode and interfacial charge injection efficiency of 97.0% can be reached. Our work inspires the development of facet-regulated BiVO4 photoanodes with high charge injection efficiency in the PEC field and provides a feasible route to enhance its charge separation efficiency.

Steering the construction of amorphous/crystalline hierarchical structure for accelerating the oxygen evolution reaction rate

As electrochemical water splitting is an extremely promising direction for solving future energy problems and the oxygen evolution reaction (OER) is the key half-reaction in water splitting, it is necessary to develop a new type of highly active and stable non-noble metal catalyst. Herein, we construct a series of hierarchical structure by modifying ZIF-67 on clustered-MnO2 nanotubes which are used as precursor. The fruit@branch-shaped compounds, marked as X@MnO2 (X = CoSx, Co3O4 and CoP). Compared with pure MnO2 nanotubes, the obtained derivatives imaginably result in the unique hierarchical structure and introduce synergistic effect between MnO2 and Co-based species that result in higher performance. In Particular, owing to the abundant active sites, a facil mass transfer pathway and improved electrical conductivity in amorphous/crystallize hierarchical structure, CoSx@MnO2 possesses the highest electrocatalytic activity with a lower overpotential of 329 mV at the current density of 10 mA cm−2, which is superior to most MnO2-based catalyst previously reported. Most importantly, to expand this strategy is an effective way to synthesize more high-activity catalysts.

On the origin of multihole oxygen evolution in haematite photoanodes

The oxygen evolution reaction (OER) plays a crucial role in (photo)electrochemical devices that use renewable energy to produce synthetic fuels. Recent measurements on semiconducting oxides have found a power law dependence of the OER rate on surface hole density, suggesting a multihole mechanism. In this study, using transient photocurrent measurements, density functional theory simulations and microkinetic modelling, we have uncovered the origin of this behaviour in haematite. We show here that the OER rate has a third-order dependence on the surface hole density. We propose a mechanism wherein the reaction proceeds by accumulating oxidizing equivalents through a sequence of one-electron oxidations of surface hydroxy groups. The key O–O bond formation step occurs by the dissociative chemisorption of a hydroxide ion involving three oxyl sites. At variance with the case of metallic oxides, the activation energy of this step is weakly dependent on the surface hole coverage, leading to the observed power law.

A mechanism in boosting H2 generation: nanotip-enhanced local temperature and electric field with the boundary layer

The sluggish kinetics of oxygen evolution reaction (OER) is the bottleneck of water splitting. Hence, we designed a nanowire Co3O4@nickel foam (Co3O4-NW@NF) electrode to boost OER utilizing the locally enhanced interfacial Joule heating and electric field within the diffusion layer. Results show that the morphology of Co3O4@NF could be regulated in nanowires, nanosheets, and nanoclusters by controlling the doping amount of fluoride ions (F−). F− served as a complexing agent to regulate the rate of crystal nucleus, and then morphologies could be tuned. compared to others, nanowire structures have a much lower potential (298 mV vs. RHE, 10 mA cm−2) and Tafel slope (48.11 mV dec-1). This better electrochemical performance was confirmed by the Density Functional Theory (DFT) that the (311) facet with oxygen vacancies of Co3O4 has a low onset potential (0.36 V) for the kinetic rate of OER. A much better mass transfer by the nanowire-enhanced interfacial Joule heating and electric field within the diffusion layer also accounted for superior OER activity, confirmed by COMSOL simulation. In a word, the design of the nanotip structure offers a novel way to boost the OER rate by enhancing electron transfer and mass transport simultaneously.

Anodic behavior of nickel in sub-molten KOH and its relevance for the production of electroactive nickel oxides

This study investigated the electrochemical behavior of pure nickel in sub-molten KOH at 200 °C and the structure of surface films formed at different anodic polarization potentials. Potentiodynamic polarization measurements showed an active-to-passive transition followed by transpassivity. Unlike aqueous alkaline solutions, surface films created in active, far passive, and transpassive regions are few microns thick. Grazing-incidence x-ray diffraction (GI-XRD), Raman, and x-ray photoelectron spectroscopy (XPS) measurements revealed that a thick and defective layer of NiO forms during polarization in the active region. Polarization into the passive regime reduces the thickness and number of defects of NiO and promotes passivity. With the formation of +3 valent nickel at far passive region, a thick, flaky adlayer of potassium-intercalated γ-NiOOH is produced. At high transpassive potentials, the flake-like morphology deteriorated with the high rate of oxygen evolution reaction (OER). The micrometer thick electroactive anodic surface films formed during active, far passive, and transpassive region became a few micrometers thick because of the high dissolution rate of Ni and the high viscosity of the sub-molten KOH.

Oxygen Evolution Reaction Driven by Charge Transfer from a Cr Complex to Co-Containing Polyoxometalate in a Porous Ionic Crystal.

Considerable efforts have been devoted to developing oxygen evolution reaction (OER) catalysts based on transition metal oxides. Polyoxometalates (POMs) can be regarded as model compounds of transition metal oxides, and cobalt-containing POMs (Co-POMs) have received significant interest as candidates. Nanocomposites based on Co-POMs have been reported to show high OER activities due to synergistic effects among the components; however, the role of each component is unclear due to its complex structure. Herein, we utilize porous ionic crystals (PICs) based on Co-POMs, which enable a composition-structure-function relationship to be established to understand the origin of the synergistic catalysis. Specifically, a Keggin-type POM [α-CoW12O40]6- and a Cr complex [Cr3O(OOCCH2CN)6(H2O)3]+ are implemented as PIC building blocks for the OER under nonbasic conditions. The potentially OER-active but highly soluble [α-CoW12O40]6- was successfully anchored in the crystalline PIC matrix via Coulomb interactions and hydrogen bonding induced by polar cyano groups of the Cr complex. The PIC exhibits efficient and sustained OER catalytic activity, while each building block is inactive. The Tafel slope of the linear sweep voltammetry curve and the relatively large kinetic isotope effect value suggest that elementary steps closely related to the OER rate involve single-electron and proton transfer reactions. Electrochemical and spectroscopic studies clearly show that the synergistic catalysis originates from the charge transfer from the Cr complex to [α-CoW12O40]6-; the increased electron density of [α-CoW12O40]6- may increase its basicity and accelerate proton abstraction as well as enhance electron transfer to stabilize the reaction intermediates adsorbed on [α-CoW12O40]6-.

The possible implications of magnetic field effect on understanding the reactant of water splitting

Electrochemical water splitting consists of two elementary reactions i.e., hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Developing robust HER and OER technologies necessitates a molecular picture of reaction mechanism, yet the reactants for water splitting reactions are unfortunately not fully understood. Here we utilize magnetic field to understand proton transport in HER, and hydroxide ion transport in OER, to discuss the possible implications on understanding the reactants for HER and OER. Magnetic field is a known tool for changing the movement of charged species like ions, e.g. the magnetic-field-improved Cu2+ transportation near the electrode in Cu electrodeposition. However, applying a magnetic field does not affect the HER or OER rate across various pH, which challenges the traditional opinion that charged species (i.e. proton and hydroxide ion) act as the reactant. This anomalous response of HER and OER to magnetic field, and the fact that the transport of proton and hydroxide ion follow Grotthuss mechanism, collectively indicate water may act as the universal reactant for HER and OER across various pH. With the aid of magnetic field, this work serves as an understanding of water might be the reactant in HER and OER, and possibly in other electrocatalysis reactions involving protonation and deprotonation step. A model that simply focuses on the charged species but overlooking the complexity of the whole electrolyte phase where water is the dominant species, may not reasonably reflect the electrochemistry of HER and OER in aqueous electrolyte.

Light-driven oxygen evolution from water oxidation with immobilised TiO2 engineered for high performance

Calcination treatments in the range of 500–900 °C of TiO2 synthesised by the sol–gel resulted in materials with variable physicochemical (i.e., optical, specific surface area, crystallite size and crystalline phase) and morphological properties. The photocatalytic performance of the prepared materials was evaluated in the oxygen evolution reaction (OER) following UV-LED irradiation of aqueous solutions containing iron ions as sacrificial electron acceptors. The highest activity for water oxidation was obtained with the photocatalyst thermally treated at 700 °C (TiO2-700). Photocatalysts with larger anatase to rutile ratio of the crystalline phases and higher surface density of oxygen vacancies (defects) displayed the best performance in OER. The oxygen defects at the photocatalyst surface have proven to be responsible for the enhanced photoactivity, acting as important active adsorption sites for water oxidation. Seeking technological application, water oxidation was accomplished by immobilising the photocatalyst with the highest OER rate measured under the established batch conditions (TiO2-700). Experiments operating under continuous mode revealed a remarkable efficiency for oxygen production, exceeding 12% of the apparent quantum efficiency (AQE) at 384 nm (UV-LED system) compared to the batch operation mode.

Mixed-​ligand-devised anionic MOF with divergent open Co(II)-nodes as chemo-resistant, bi-functional material for electrochemical water oxidation and mild-condition tandem CO2 fixation

Metal-organic frameworks (MOFs) combine unique merits of heterogeneous and molecular catalysts, where purposeful implantation of task-specific functionalities along the pore structure can promise electrocatalytic oxygen evolution reaction (OER) and cascade chemical valorization of CO2. Although, both these attributes are crucial for renewable energy and environmental remediation, their effective amalgamation over a single platform is hitherto unexplored, yet extremely demanding. The chemically robust, and non-penetrated charged framework CSMCRI-10 (CSMCRI = Central Salt & Marine Chemicals Research Institute) exemplifies activation induced generation of high density Co(II) nodes with diverse open coordination positions along the unidirectional porous channels, and act as unique bi-functional material. Building on the presence of redox-active [Co2(µ2-OH)(COO)4] secondary building units, the activated framework (10a) demonstrates efficient water oxidation in alkaline medium (1 M KOH). The MOF requires only 396 mV overpotential to reach 10 mA/cm2 anodic current density, and possesses a Tafel slope of 102 mV/decade with admirable 95.1% Faradaic efficiency, signifying high rate of oxygen evolution reaction. The OER turn-over frequency is found to be within the range of best reported values (0.03s−1), and the framework stability is preserved in both potentiodynamic and potentiostatic conditions over 500 consecutive cycles. Further, the Lewis acid functionalized 10a benefits solvent-free CO2 conversion to cyclic carbonate in highly synergistic manner with adequate reusability and broad substrate scope. To the best of tandem catalysis, rarest oxidative carboxylation of CO2 and styrene is realized via single-step styrene carbonate synthesis with exceptional conversion under relatively mild reaction condition.

Electrochemical Performance of New Bilayer Oxygen Electrode for Reversible Solid Oxide Cells

High-temperature solid oxide cells (HT-SOCs) have innate advantages over their low-temperature counterparts in efficiency and production rate since part of the chemical energy in the products comes directly from the heat and the operating current density (proportional to H2 production rate) is high. However, a major obstacle for HT-SOCs to be commercially viable is the poor long-term stability, particularly at high current densities. The rudimentary cause for the instability is believed to result from the mechanical delamination of oxygen electrode (OE) from the electrolyte due to the mismatch in oxygen evolution reaction (OER) rate and applied current density, which results in high oxygen partial pressure at the interface. Therefore, a way to minimize the delamination is to enhance OE’s OER rate (i.e. reduce OER area-specific-resistance, ASR) to match the high applied current density. In this presentation, we show the employment of three-electrode symmetrical cell method to exclusively characterize the OER’s ASR of bilayer OE under applied current density at high temperatures. The results explicitly show that the bilayer OE with low OER’s ASR outperforms the baseline single layer OE (LSCF-GDC) in long-term stability at high current density of 1 A/cm2 and 700oC; the former can last ~1000 hrs under a constant 1A/cm2 current before observing performance degradation and delamination, whereas the latter shows significant performance degradation and delamination even after 100 hrs. We conclude that the bilayer OE exhibits a better chemical, thermal, mechanical, and more importantly electrochemical stability over the benchmark single layer LSCG-GDC OE.