Efficient Bifunctional Catalyst Research Articles

Aminophosphonium organocatalysts for the ring-opening copolymerisation of epoxide and cyclic anhydride.

The Kirsanov reaction has been used to synthesise air stable, efficient and selective bifunctional aminophosphonium catalysts for the alternating ring-opening copolymerisation of cyclohexene oxide and phthalic anhydride without the need for a co-initiator.

CoFe2O4 with the In-Situ Formed Oxygen Vacancies and Co Particles as an Efficient Bifunctional Catalyst for Rechargeable Zinc-Air Batteries.

Rechargeable zinc-air batteries (RZABs) are considered as one of the most promising clean energy device due to their abundant resources, low cost and environmental friendliness. However, their energy efficiency and cycle life are far from satisfactory due to the poor activity and stability of bi-functional electrocatalyst in air cathode. In this work, an efficient bi-functional catalyst (rGO-CoFe2O4/Co) was derived from its precursor (rGO-CoFe2O4) through a simple annealing process. Electrochemical measurements prove that rGO-CoFe2O4/Co with the in-situ formed Co nano particles and rich oxygen vacancies appears excellent oxygen reduction reaction and oxygen evolution reaction catalytic activity compared to its counterpart. Its half-wave potential is 0.81 V (vs RHE) and the OER overpotential is only 310 mV (vs RHE). In addition, rechargeable zinc-air batteries assembled with rGO-CoFe2O4/Co show the highest peak power density (128.9 mW cm-2) and cycling stability compared to rGO-CoFe2O4 and commercial Pt/C-RuO2 catalysts. This work provides a simple strategy for the design of advanced bifunctional catalysts.

Efficient, chlorine-free, and durable alkaline seawater electrolysis enabled by MOF-derived nanocatalysts

The development of cost-effective, scalable, and non-precious based bifunctional catalysts that can efficiently catalyze the sluggish oxygen and hydrogen evolution reactions (OER and HER) in the highly corrosive seawater medium is challenging, yet vital to realize a practical seawater electrolyzer. In this work, we demonstrate a nickel-exchanged zeolitic imidazolate framework (Ni@ZIF67)-derived nickel-cobalt-cobalt oxide nanoparticles embedded amorphous carbon (Ni–Co–CoO@C) nanocomposite as an efficient, chloride-resistant, and stable bifunctional catalyst in alkaline seawater. The OER and HER activities are meticulously characterized by comparing nanocomposites prepared at different pyrolysis temperatures. Ni@ZIF67 pyrolyzed at 700 °C (NZ700) exhibits the lowest OER overpotential (281 mV @ 10 mA cm−2) whereas that pyrolyzed at 500 °C reveals the lowest HER overpotential (196 mV @ 50 mA cm−2) in alkaline seawater. The NZ700||NZ700 cell also exhibits the lowest overall splitting voltage in alkaline seawater (1.72 V @ 20 mA cm−2). Detailed post-electrolysis studies are also carried out to explore the origin of the electrocatalytic activities. Furthermore, a zero-gap, flow-cell type alkaline seawater electrolyzer prototype has been fabricated to demonstrate the viability of our catalysts.

Boosting the bifunctional catalytic activity of Co3O4 on silver and nickel substrates for the alkaline oxygen evolution and reduction reactions

Developing an efficient bifunctional catalyst for oxygen reduction (ORR) and evolution reactions (OER) is a crucial step for the wide commercialization of alkaline water electrolyzers. However, a proper assessment and comparison of various catalysts is still challenging due to the different catalyst substrates and loadings. In this work, Co3O4 spinel nanoparticles (NPs) were investigated as a bifunctional catalyst at different substrates of glassy carbon or Ag bulk substrate or Ni particles and with different loadings. For Co3O4 (800 µg cm-2)/Ag electrode, not only the overpotential for ORR was 50 mV lower than the bare Ag electrode, but also the OER overpotential was 40 mV lower than the sole Co3O4. Besides, less than 1% peroxide intermediate was detected during ORR using the rotating ring disc electrode (RRDE) method, suggesting a 4-electron O2 reduction. Tafel slopes of 70 and 60 mV dec‑1 at Co3O4/Ag were obtained for ORR and OER, respectively. The improved bifunctional activity could be attributed to a synergistic effect between Co3O4 and the Ag support. For the loading effect, it is revealed that the number of accessible sites of Ag surface decreases with increasing the Co3O4 loading, as evaluated from lead-underpotential deposition measurements. Interestingly, after running ORR/OER cycles, the surface area increased by 4–6 times. This surface roughening was also confirmed by SEM and EDX. The study was extended to Co3O4+Ni mixed catalyst to validate the effect of the support on this induced synergism. Hence, this work provides a simple route for designing potential effective catalytic interfaces and contributes to unravelling the influence of the substrate and loading on the catalyst activity for water electrolyzers.

Heterointerface of nickel-ferric hydroxide / cobalt-phosphide-boride boosting hydrazine-assisted water electrolysis

Sustainable H2 production based on hydrogen evolution reaction (HER) and hydrazine oxidation reaction (HzOR) has attracted wide attention due to minimal energy consumption compared to overall water electrolysis. The present study focuses on the design and construction of heterostructured CoPB@NiFe–OH applied as efficient bifunctional catalysts to sustainable produce hydrogen and remove hydrazine in alkaline media. Impressively, CoPB@NiFe–OH heterointerface exhibits an HzOR potential of −135 mV at the current density of 10 mA cm−2 when the P to B atom ratio was 0.2, simultaneously an HER potential of −32 mV toward HER when the atom ratio of P and B was 0.5. Thus, hydrogen production without an outer voltage accompanied by a small current density output of 25 mA cm−2 is achieved, surpassing most reported catalysts. In addition, DFT calculations demonstrate the Co sites in CoPB upgrades H∗ adsorption, while the Ni sites in NiFe–OH optimizes the adsorption energy of N2H4∗ due to electron transfer from CoPB to NiFe–OH at the heterointerface, ultimately leading to exceptional wonderful performance in hydrazine-assistant water electrolysis via HER coupled with HzOR.

Axial modulation of catalysis mechanism via charge-asymmetric for enhanced electrocatalytic performance toward hydrogen and oxygen evolution reactions

Designing efficient, stable, and nonprecious metal bifunctional catalysts is warranted for realizing the industrial application of electrocatalytic overall water splitting. Herein, we report a new catalyst (CoFe/SNC) for the HER and OER. The active site of catalysis composed of two charge-asymmetric Co/Fe atoms could axial modulation of the catalysis mechanism, thus improving the kinetics of the HER and OER. Moreover, the use of hollow porous carbon spheres as catalyst support not only enhances the distribution of Co/Fe atoms but also improves the mass transfer during the HER and OER processes. Therefore, the CoFe/SNC displays a good alkaline HER and OER activity with a small overpotential of 96.2 mV and 285.8 mV at 10 mA cm−2, respectively. Theoretical calculations reveal that the Fe atoms with optimal absorption energy for the hydrogen intermediate and the Co centers with a reduced energy barrier for the rate-determining step are the active sites for HER and OER, respectively. Additionally, the synergistic effect of Co/Fe dual-atoms could effectively optimize the intermediate adsorption of Co/Fe-N4 sites and improve the barriers of HER and OER activity and stability. This study provides valuable insight for designing bifunctional alkaline water-splitting electrocatalysts.

Plasma-engineering of Pt-decorated NiCo2O4 nanowires with rich oxygen vacancies for enhanced oxygen electrocatalysis and zinc-air battery performance

The development of low-cost and efficient bifunctional catalysts is of great importance for the advancement of high-performance rechargeable zinc-air batteries. In this study, we present a composite material comprising Pt-decorated NiCo2O4 nanowires enriched with abundant oxygen vacancies, designed as an excellent bifunctional electrocatalyst for both the oxygen evolution reaction and the oxygen reduction reaction. The introduction of Pt atoms and oxygen vacancies onto the NiCo2O4 nanowires was achieved with the assistance of plasma treatment. This approach resulted in a catalyst with a greater number of active sites, enhanced surface conductivity and significantly improved electrocatalytic activity compared to the original NiCo2O4 nanowires. Moreover, the zinc-air battery based on this composite catalyst exhibits a narrow charge/discharge voltage gap and superior stability, which is better than batteries employing commercial noble-metal-based catalysts. This work provides a rational strategy for the construction of high-active and cost-effective Pt-based electrocatalysts.

Dual‐Carbon Assisted Oxygen Vacancy Engineering for Optimizing Mn(III) Sites to Enhance Zn–air Battery Performances

AbstractOwing to kinetic‐sluggish nature of electrocatalytic oxygen transformation processes, it is pivotal to develop durable and efficient bifunctional air electrode catalysts for fabricating high‐performance Zn–air batteries (ZABs). In this work, oxygen vacancy (Ov) induced Mn(III) sites optimization is achieved via nano‐micro structure modulation. Protonated carbon nitride (p‐C3N4) is applied as a structure‐stiffening module to immobilize α‐MnO2 on N/P‐doped active carbon (NPAC) and induce Ov construction. X‐ray adsorption spectra (XAS) disclose the formation of Ov and Mn(III) sites in MCC, the unit coordination structure is well maintained with the aid of a dual‐carbon strategy. Mn(III) sites efficiently catalyze oxygen reduction/evolution reaction (ORR/OER), MCC shows high half‐wave potential (E1/2) of 0.88 V for ORR and low potential at 10 mA cm−2 (Ej = 10) of 1.64 V for OER. According to density functional theory (DFT) simulations analysis, the gorgeous bifunctional activity is owing to that optimized charge distribution facilitates the intermediates transformation. Aqueous ZABs based on MCC manifests high peak power density of 452 mW cm−2 and durable cycling stability of 1640 h. Quasi‐solid‐state ZABs based on MCC also show satisfactory performances (175 mW cm−2, 105 h). This work provides the route to develop efficient and durable electrocatalyst for constructing ZABs with long lifespan and high‐power‐density.

Construction of atom-scale Co/Fe/Ni M-N-C active sites within nitrogen-doped carbon spheres for high-performance bifunctional oxygen catalysts in rechargeable zinc-air batteries

Developing carbon-based catalysts with metal‑nitrogen‑carbon (M-N-C) active sites as efficient and low-cost bifunctional catalysts to replace precious metal catalysts for rechargeable zinc-air batteries devices has garnered significant attention. Herein, nitrogen-doped submicron carbon-based spherical bifunctional electrocatalysts (CNPD-CoFeNi) with abundant atom-scale Co/Fe/Ni M-N-C active sites and defects were synthesized. The introduction of massive amounts of Zn species increases the spatial distance of Co/Fe/Ni metal sites to prevent aggregation during pyrolysis, and the evaporation of Zn at high temperatures creates defects synergizing with M-N-C. Consequently, CNPD-CoFeNi possesses a stable carbon-based spherical structure, high electrical conductivity, rich nitrogen content, abundant atom-scale Co/Fe/Ni M-N-C active sites, and defects, displaying outstanding durability, oxygen reduction reaction (ORR) activity with a half-wave potential of 0.87 V, and satisfactory OER performance, surpassing or comparable with the state-of-art Pt/C and RuO2, respectively. Notably, liquid Zn-air batteries with CNPD-CoFeNi catalyst exhibit an exceptional high peak power density of 146.5 mW cm−2 and stable charge-discharge cycling over 270 h, outperforming Pt/C-RuO2 based devices. Additionally, the all-solid-state Zn-air battery also displays satisfactory practicability and stability. The synthesis strategy and its remarkable results provide valuable guidance and inspiration for the future advancement of precious metal substitutes in ORR/OER and rechargeable zinc-air batteries.

Highly efficient FeS/Fe3O4 @ biomass carbon bifunctional catalyst with enriched oxygen vacancies for heterogeneous electro-Fenton catalysis

Low H2O2 production, narrow adaptive pH range and slow Fe(II) regeneration on the cathode still limit efficiency of electro-Fenton (EF) and its application. Herein, we designed a bifunctional catalyst with FeS and Fe3O4 nanoparticles dispersed on porous carbon (CFeS@C) using template of sodium alginate (SA)/FeSO4 hydrogel mixed with carbon black (CB), which presented high H2O2 generation efficiency and outstanding tetracycline degradation efficiency under wide pH ranges (3-8) with a low energy consumption of 19.6 kWh/kg total organic carbon (TOC). The introduction of CB created abundant oxygen vacancies in CFeS@C, promoting the oxygen adsorption and the electrochemical generation of H2O2, which further boosted the formation of •OH due to the interaction with Fe2+ on the cathode surface. Simultaneously, the reaction between the outer layer of FeS and Fe3+ not only accelerated iron cycling but also reduced the solution pH. It was verified that •OH and 1O2 played a dominant role in organics degradation. The system maintained stability after 10 cycles and effectiveness in the treatment of pharmaceutical wastewater. This study would offer a new strategy to develop an efficient and durable bifunctional catalyst for heterogeneous EF system working in wide pH conditions for wastewater treatment.

Biomass-incorporated KNO3-C/γ-Al2O3 bifunctional catalyst for efficient biodiesel production

Biodiesel has gained attention as a promising renewable and sustainable alternative to fossil fuels, which necessitated the development of an effective and eco-friendly catalyst for transesterification processes. Herein, this research reported the development of a highly efficient bifunctional catalyst by incorporating carbon from oil palm leaves (OPLs) into KNO3/γ-Al2O3 catalyst, synthesized through a facile method, to concurrently catalyze the waste cooking oil (WCO) transesterification and free fatty acids (FFAs) esterification in a one-pot reaction. Proposed Box-Behnken Design (BBD) model's ideal conditions, experimentally yielded an average of 93.74 % biodiesel yield. Meanwhile, analysis revealed that the catalyst with 30 wt% KNO3 loadings and 1.0 g oil palm leaves dosage (OPLD), calcined at 700 °C, has a BET surface area of 46.93 m2/g and exhibited the presence of K2O, K2O2 and K2C2 active species on the catalyst surface. In addition to exhibiting high total basicity and acidity of 2.9 mmol/g and 2.1 mmol/g, respectively, environmental studies suggested this catalyst generated less waste, highlighting its significant potential of being used for efficient biodiesel production. Therefore, present research introduces a new approach for synthesizing a fruitful and ecofriendly bifunctional catalyst to attain one-pot biodiesel production from low-grade oils.

Electronic structure engineering of CNTs@NiFe-LDH composite via heteroatom doping for efficient seawater electrolysis

Exploring cost-effective, efficient, and durable bifunctional electrocatalysts for seawater splitting is crucial for green hydrogen production. Electronic structure engineering stands out as a promising method to tailor catalyst properties and enhance catalytic performance. In this work, a bifunctional composite, N-CNTs@NiFeZr-LDH, for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), is designed and fabricated. Results show that the incorporation of Zr into NiFe-LDH and N into CNTs generates a synergistic effect that optimizes the electronic structure of the composite, leading to a noticeable improvement in catalytic performance. Interestingly, a straightforward calcination treatment further enhances the catalytic performance. The optimized sample exhibits a current density of 100 mA cm−2 with ultra-low overpotentials of 210 and 185 mV for the HER and OER, respectively, in simulated seawater (1.0 M KOH + 0.5 M NaCl). When applied to overall water splitting in simulated seawater, a two-electrode electrolyzer assembled by the optimized sample achieves a current density of 350 mA cm−2 with only 1.65 V, and can operate steadily for 100 h. In natural seawater, the assembled electrolyzer delivers 350 mA cm−2 requiring only 1.68 V, together with an impressive stability. Besides offering an efficient bifunctional catalyst for seawater electrolysis, this work underscores the crucial role of electronic engineering in enhancing the intrinsic catalytic activity.

Microenvironment Tailoring of NiCo Alloys Coupled with FePc as Efficient Bifunctional Catalysts for High-Rate Zn-Air Batteries.

The practical application of Zn-air batteries require exploring cost-effective and durable bifunctional electrocatalysts. However, the simultaneous preparation of catalysts with bifunctional activities for oxygen reduction reaction (ORR) and oxygen precipitation reaction (OER) remains challenging. Herein, we synthesized a novel hybrid catalyst (FePc/NiCo/CNT), which couples NiCo alloy with FePc through electrostatic interaction. The interaction between FePc and NiCo alloy can enhance the intrinsic catalytic activity of the active site Fe-N4 and prevent the electrolyte corrosion of the metal alloy, ultimately improving the stability of the catalyst by the microenvironment-tailoring strategy. The resultant FePc/NiCo/CNT catalyst exhibits outstanding oxygen reduction reaction (ORR) activity with a half-wave potential of 0.88 V, which is attributed to the abundant Fe-Nx active sites. Furthermore, the electron interactions between NiCo/CNT and FePc accelerate electron transfer and enhance the activation of oxygen intermediates, consequently boosting the OER activity with an overpotential of 260 mV at 10 mA cm-2. The Zn-air batteries assembled with FePc/NiCo/CNT show a high power density of 175.1 mW cm-2 and excellent cycling stability for up to 430 h at 20 mA cm-2. The preparation of oxygen electrode catalysts for renewable clean energy devices can be made more convenient with this directly engineered strategy for ORR and OER active centers.

N,S‐doped Zeolite‐Templated Carbon Like Substrate Supported NixFeySz Nanoparticles as an Efficient Bifunctional Catalyst for Rechargeable Zinc Air Batteries

N,S‐doped Zeolite‐Templated Carbon Like Substrate Supported NixFeySz Nanoparticles as an Efficient Bifunctional Catalyst for Rechargeable Zinc Air Batteries

In situ synthesis of nanosized ZSM-12 zeolite isomorphously substituted by gallium for the n-hexadecane hydroisomerization

The ZSM-12 zeolite has attracted attention as the promising acid component of bifunctional catalysts for the n -alkane hydroisomerization because of its large size of micropore openings (0.57 nm × 0.61 nm) with 12-membered-ring and one-dimensional channels. However, the larger crystal size and stronger Brønsted acid strength of microsized ZSM-12 zeolite will lead to cracking of iso -olefin intermediates and decrease the iso -alkane yield. In this study, ZSM-12 zeolite samples partially and completely isomorphously substituted with gallium ([Ga,Al]Z12 and GaZ12) were in situ synthesized. The characteristic results indicate that isomorphous substitution by Ga can effectively reduce the crystal size to increase the mesoporosity and weaken the Brønsted acidity of the [Ga,Al]Z12 and GaZ12 samples. In addition, bifunctional catalysts with more appropriate metal-acid proximity for n -hexadecane hydroisomerization were prepared by mixing the 0.6Pd/A sample with 0.6 wt.% Pd loaded on γ-Al2O3 and the ZSM-12, [Ga,Al]Z12 and GaZ12 samples, respectively. The 0.3Pd/A-[Ga,Al]Z12 and 0.3Pd/A-GaZ12 catalysts both promote the maximum iso -hexadecane yield and distribution of multi-branched iso -hexadecane products due to their enhanced mesoporosity, reduced Brønsted acid strength, increased CPd/CH+ ratios and improved metal-acid balance. Especially for the 0.3Pd/A-GaZ12 catalyst, when the n -hexadecane conversion is 93.5%, the maximum iso -hexadecane yield reaches 80.6%, and the proportion of multi-branched iso -hexadecane products is 64.6%, which are both the highest among all investigated catalysts. Accordingly, Ga isomorphous substitution is an effective strategy to develop the efficient bifunctional catalysts for hydroisomerization.

PtCo nanoalloy embedded nitrogen-doped carbon nanotube for rechargeable Zn-air batteries

The large-scale application of metal-air batteries strongly depends on the development of cost-effective, highly efficient, and durable bifunctional oxygen catalysts. In this work, a facile approach for preparing the monodisperse PtCo nanoalloy anchored the nitrogen-doped carbon nanotubes (PtCo/NCNT) for zinc-air batteries is reported. The nitrogen-doped carbon shell prevents PtCo nanoalloy from exfoliation, dissolution, and aggregation and enables the accessibility of electrolytes to the alloy surface and the electron transfer. Besides, the strong interaction between PtCo nanoalloy and nitrogen-doped carbon can efficiently modulate the electronic structure of the formed active sites. When used as a cathode catalyst, the constructed rechargeable zinc-air battery presents higher power density (268 mW cm−2), specific capacity (840 mAh g−1), and excellent stability. More importantly, the PtCo/NCNT catalyst allows the all-solid-state cell to exhibit remarkable flexibility and high round-trip efficiency at various bending states, demonstrating a potential possibility to replace the conventional Pt/C and RuO2 catalysts.

Metal-Organic Framework with Dual Excitation Pathways as Efficient Bifunctional Catalyst for Photo-assisted Li-O2 Batteries.

Li-O2 batteries (LOBs) have sparked significant interest due to their fascinating high theoretical energy density. However, the large overpotential for the formation and oxidation of Li2O2 during charge and discharge process seriously hinders the further development and application of LOBs. In this work, metal-organic frameworks (MOFs) with different metal clusters (Fe, Ti, Zr) are successfully synthesized, and they are employed as the photoelectrodes for the photo-assisted LOBs. The special dual excitation pathways of Fe-MOF under illumination and the superior separation efficiency of photocarriers, which significantly enhance the activation of O2/Li2O2, improving the catalytic activity of oxygen reduction reaction and oxygen evolution reaction. Moreover, compared to traditional inorganic semiconductor crystals, Fe-MOF exhibits large specific surface area and excellent O2 adsorption ability. Therefore, the LOB with Fe-MOF as the cathode exhibits large specific capacity, ultralow charge/discharge overpotential of 0.22V at 0.05mA cm-2 and excellent stability of 195 cycles under illumination. This study provides an environmentally friendly and highly efficient photocatalyst for LOBs, and a new strategy for designing photoelectrodes.

Fabrication of cobalt phosphide/nitride/carbon nanotube composite: An efficient bifunctional catalyst for hydrogen and oxygen evolution

Designing composites with rational structure and composition is a promising approach to obtain efficient electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In this study, zeolitic imidazolate frameworks-67 (ZIF-67) is employed as a self-sacrificing template to synthesize Co/carbon nanotubes (CNTs) precursor, which is subsequently in-situ nitrided and phosphorized to form cobalt phosphide/nitride/carbon nanotubes (Co2P/Co4N/CNTs) composite. The realized Co2P/Co4N composite exhibits heterogeneous nanoparticle microstucture with an average diameter of approximately 10 nm, encapsulated by carbon nanotubes with a porous dodecahedral array. Moreover, there is a well-defined interface between cobalt phosphide, cobalt nitride phases, and carbon nanotubes species. Benefiting from the synergistic effect of Co4N and Co2P, rich active sites, and high conductivity of CNTs, the composite catalyst demonstrates remarkable HER and OER activities, requiring overpotentials of 228 and 389 mV to support 100 mA cm−2 current density, respectively. This work presents a novel strategy for designing efficient bifunctional catalysts towards HER and OER.

NiFeP nanosheet arrays supported on nickel nitrogen codoped carbon nanofiber as an efficient bifunctional catalyst for overall water splitting

Transition metal phosphides have emerged as effective electrocatalysts for water splitting. In this study, novel NiFeP nanosheet arrays supported on nickel nitrogen codoped carbon nanofiber (NiFeP@Ni-NCNF) was synthesized through a combination of electrospun, template-directed growth, and phosphorization strategy. The utilization of Ni-NCNF as a substrate for constructing the nanoarrays structure with superhydrophilic and superaerophobic properties significantly enhances the electrochemical active specific surface area of the electrocatalytic material. The synergistic effect of Ni2P and Fe2P and the excellent conductivity of the Ni-NCNF substrate promote NiFeP@Ni-NCNF to exhibit excellent HER/OER electrocatalytic properties. The NiFeP@Ni-NCNF exhibits low overpotentials of 131 mV and 204 mV for HER and OER at 10 mA cm−2, respectively. Additionally, using NiFeP@Ni-NCNF as the anode and cathode of the electrolytic water device displays a voltage of 1.61 V at 10 mA cm−2, and the Faraday efficiency of the two electrodes is near 100 %. This research presents an extensible and cost-effective strategy for synthesizing phosphide-based catalysts with unique nanostructures and desirable water splitting catalytic properties.

Hierarchical Porous Carbon Supported Co2P2O7 Nanoparticles for Oxygen Evolution and Oxygen Reduction in a Rechargeable Zn-Air Battery.

The oxygen reduction/evolution reaction (ORR/OER) represents a pivotal process in metal-air batteries; however, it is constrained by the limitations of slow kinetics. Nevertheless, the creation of long-lasting and bifunctional catalysts represents a significant challenge. This study presents a series of hierarchical porous carbon-supported cobalt pyrophosphate (Co2P2O7-N/C-T) catalysts, prepared through the pyrolysis of porphyrin-based NTU-70 nanosheets with red phosphorus at varying temperatures. The Co2P2O7-N/C-800 not only demonstrates remarkable OER performance with an overpotential of only 290 mV at a current density of 10 mA cm-2 in 1 M KOH, but also exhibits an excellent ΔE of 0.74 V in 0.1 M KOH, which is lower than that of Pt/C + RuO2 (0.76 V). The utilization of Co2P2O7-N/C-800 as an air cathode in a rechargeable Zn-air battery (ZAB) results in a stable discharge voltage plateau of 1.405 V and a high gravimetric energy density of 801.2 mA h gZn-1. This work presents a promising strategy for the design of efficient bifunctional catalysts and demonstrates the critical importance of the interplay between the active center and the supported hierarchical porous carbon.