High-performance Oxygen Reduction Reaction Research Articles

Asymmetrically Coordinated Calcium Single Atom for High-Performance Oxygen Reduction Reaction.

S-block single atoms represent an ideal catalyst for the oxygen reduction reaction (ORR) as they can suppress the Fenton reaction. However, the symmetry of the s/p orbitals tends to generate either an excessively strong or weak interaction with intermediates. Herein, Ca single atoms coordinated with -S, -OP, and three N atoms (Ca/NPS-HC) were fabricated to modulate the adsorption of intermediates and promote the efficiency of s-block ORR catalysts. The experimental results from ORR demonstrated that the Ca/NPS-HC catalyst exhibited outstanding catalytic capability with a half-wave potential of 0.89 V, a kinetic current density of 56.6 mA cm-2 at 0.85 V, and a Tafel slope of 42 mV dec-1, outperforming commercial Pt/C. The detailed mechanistic studies revealed that the asymmetric coordination of Ca single atoms led to the symmetry-breaking of electron distribution in Ca single atoms, attenuating the s-p hybridization from the intermediate adsorption process, and thereby minimizing the energy barrier of the whole ORR.

N, S co-doped carbon nanotubes loaded with Cu nanoclusters for efficient oxygen reduction reaction.

Developing highly superior precious-metal-free electrocatalysts for oxygen reduction reaction (ORR) are challenging and great significance. In this study, it is reported that an efficient ORR catalysts with N and S co-doped carbon nanotubes anchored to copper (Cu) nanoclusters by mechanical grinding and high temperature heat treatment. The obtained Cu-S1-N-C electrocatalysts exhibited a high ORR performance with an onset potential (Eonest) of 0.989 V and a half-wave potential (E1/2) of 0.905 V (vs. RHE) in alkaline electrolyte, which was superior to that of commercial Pt/C catalyst. In contrast to N doping alone, the defect structures and active species of the catalysts were optimized by precise modulation of S-atom doping, and moreover, the introduction of S-atoms provided more thiophene-sulfur active sites. This study provides an innovative idea for designing excellent ORR catalysts.

Design of Atomically Dispersed CoN4 Sites and Co Clusters for Synergistically Enhanced Oxygen Reduction Electrocatalysis.

Constructing dual-site catalysts consisting of atomically dispersed metal single atoms and metal atomic clusters (MACs) is a promising approach to further boost the catalytic activity for oxygen reduction reaction (ORR). Herein, a porous CoSA-AC@SNC featuring the coexistence of Co single-atom sites (CoN4) and S-coordinated Co atomic clusters (SCo6) in S, N co-doped carbon substrate is successfully synthesized by using porphyrinic metal-organic framework (Co-TPyP MOF) as the precursor. The introduction of the sulfur source creates abundant microstructural defects to anchor Co metal clusters, thus modulating the electronic structure of its surrounding carbon substrate. The synergistic effect between the two types of active sites and structural advantages, in turn, results in high ORR performance of CoSA-AC@SNC with half-wave potential (E1/2) of 0.86V and Tafel slope of 50.17mVdec-1. Density functional theory (DFT) calculations also support the synergistic effect between CoN4 and SCo6 by detailing the catalytic mechanism for the improved ORR performance. The as-fabricated Zn-air battery (ZAB) using CoSA-AC@SNC demonstrates impressive peak power density of 174.1mWcm-2 and charge/discharge durability for 148h. This work provides a facile synthesis route for dual-site catalysts and can be extended to the development of other efficient atomically dispersed metal-based electrocatalysts.

Facile and fast fabrication of CuCo alloy and N-codoped hierarchical porous carbon catalyst for efficient oxygen reduction reaction in microbial fuel cells

Designing a low-cost, high-performance oxygen reduction reaction (ORR) catalyst to replace the precious metal catalyst remains a huge challenge for microbial fuel cells (MFCs). Herein, a facile and rapid approach to fabricate highly active N-doped hierarchical porous carbon (NHPC) supported bimetal CuCo/NHPC composites with densely accessible active sites is developed by pyrolysis of Cu-doped ZIF-67 (CuCo-ZIF) precursor. In which, CuCo-ZIF precursor is synthesized through a one-pot hydrothermal method. Results showed that in addition to create additional Cu-Nx sites and increase N content, the Cu doping induces a hierarchical porous structure CuCo/NHPC composite with pores centered around 2.4, 4.2 nm and 10–60 nm, which can significantly accelerate the mass/electron transfer and improve efficient utilization of the active sites. The resulting CuCo/NHPC composite provides abundant active sites, high content of pyridinic-N and graphitic-N, which significantly boosts ORR performances. The CuCo/NHPC-T with pyrolysis temperature of 800 °C achieves remarkable ORR activity with low charge transfer resistances, high half-wave potential. The MFC assembled with CuCo/NHPC-800 (774.2 mW·m−2 and 0.713 V) significantly outperforms MFC assembled with Co-NC-800 (541.9 mW·m−2 and 0.583 V) in terms of maximum power density and open-circuit voltage. Moreover, the output voltage of MFC assembled with CuCo/NHPC-800 exhibited no significant downward trend within 30 days, which was better than that of Pt/C catalyst. This work provides a feasible time-saving route to develop promising nitrogen-enriched mesoporous carbon bimetallic ORR catalysts.

Bimetallic-doped three-dimensional carbon skeleton porous material as efficient catalysts for oxygen reduction reaction

The slowness of the oxygen reduction reaction (ORR) kinetics of the fuel cell cathode has terrifically inhibited its development process. Now it is of considerable importance to research low-cost, multi-defect, high-performance non-noble metal ORR catalysts. Specifically, CuO nanosheets are grown in situ on ZIF-8 to form a composite material (zif-8@CuO), and then undergo a high-temperature carbonization process. Finally, the Zn-Cu codoped composite material Zn-xCu-N/C with a porous structure supported by a three-dimensional carbon skeleton can be obtained. The material has a 3D carbon skeleton support and a rich pore structure, which can expose more active sites. The combination of bimetallic Zn and Cu with carbon materials also increases the overall stability and conductivity of the material, which is beneficial to improvement of catalytic performance. The electrochemical performance test results show that the onset potential and half-wave potential of the Zn-0.1Cu-N/C material are 0.889 V and 0.803 V respectively, with a low Tafel slope of 62 mV dec−1 and excellent long-term stability. After 10000 cycles, the ORR curve only changed 18 mV, while the carbon skeleton can still maintain unchanged.

Upcycling retired Li-ion batteries into high-performance oxygen reduction reaction electrocatalysts in flexible Al-air batteries

Upcycling retired lithium-ion batteries (LIBs) into value-added electrocatalysts represents a promising strategy for tuning the trash into treasure. Herein, an effective approach is reported to convert the LIB anode residues into electrocatalysts that enhance the oxygen reduction reaction (ORR). The residues are utilized for synthesizing reduced graphene oxides (rGO) with Mn nanoparticles anchored by N and S dopants (Mn/NS-rGO). A Pt/C-comparable ORR performance is achieved in alkaline media, with the onset and half-wave potentials of 1.01 and 0.87 V, as well as the excellent durability. Density functional theory (DFT) calculations reveal that Mn sites, coordinating with N and S dopants, simultaneously optimize the intermediate adsorption and charge distribution, which in turn facilitates ORR. The solid-state Al-air batteries are assembled by using Mn/NS-rGO as the cathode catalyst, showing the power density of 103.8 mW cm−2, which successfully charge a cell phone and power LED lights under flexible working conditions.

Highly Dispersed Mn-Doped Ceria Supported on N-Doped Carbon Nanotubes for Enhanced Oxygen Reduction Reaction.

The weak adsorption of oxygen on transition metal oxide catalysts limits the improvement of their electrocatalytic oxygen reduction reaction (ORR) performance. Herein, a dopamine-assisted method is developed to prepare Mn-doped ceria supported on nitrogen-doped carbon nanotubes (Mn-Ce-NCNTs). The morphology, dispersion of Mn-doped ceria, composition, and oxygen vacancies of the as-prepared catalysts were analyzed using various technologies. The results show that Mn-doped ceria was formed and highly dispersed on NCNTs, on which oxygen vacancies are abundant. The as-prepared Mn-Ce-NCNTs exhibit a high ORR performance, on which the average electron transfer number is 3.86 and the current density is 24.4% higher than that of commercial 20 wt % Pt/C. The peak power density of Mn-Ce-NCNTs is 68.1 mW cm-2 at the current density of 138.9 mA cm-2 for a Zn-air battery, which is close to that of 20 wt % Pt/C (69.4 mW cm-2 at 106.1 mA cm-2). Density functional theory (DFT) calculations show that the oxygen vacancy formation energies of Mn-doped CeO2(111) and pure CeO2(111) are -0.55 and 2.14 eV, respectively. Meanwhile, compared with undoped CeO2(111) (-0.02 eV), Mn-doped CeO2(111) easily adsorbs oxygen with the oxygen adsorption energy of only -0.68 eV. This work provides insights into the synergetic effect of Mn-doped ceria for facilitating oxygen adsorption and enhancing ORR performance.

One-Pot Etching Pyrolysis to Defect-Rich Carbon Nanosheets to Construct Multiheteroatom-Coordinated Iron Sites for Efficient Oxygen Reduction.

Constructing multiheteroatom coordination structure in carbonaceous substrates demonstrates an effective method to accelerate the oxygen reduction reaction (ORR) of supported single-atom catalyst. Herein, the novel etching route assisted by potassium thiocyanate (KCNS) is developed to convert metal-organic framework to 2D defect-rich porous N,S-co-doped carbon nanosheets for anchoring atomically dispersed iron sites as the high-performance ORR catalysts (Fe-SACs). The well-designed KCNS-assisted etching route can generate spatial confinement template to direct the carbon nanosheet formation, etching condition to form defect-rich structure, and additional sulfur atoms to coordinate iron species. Spectral and microscopy analysis reveals that the iron element in Fe-SACs is highly isolated on carbon nanosheet and anchored by nitrogen and sulfur atoms in unsymmetrical Fe-S1N3 structure. The optimized Fe-SACs with large specific surface area could show remarkable alkaline ORR performances with a high half-wave potential of 0.920 V versus RHE and excellent durability. The rechargeable zinc-air battery assembled with Fe-SACs air electrodes delivers a large power density of 350 mW cm-2 and a stable voltage platform during charge and discharge over more than 1300 h. This work proposes a novel strategy for the preparation of single-atom catalysts with multiheteroatom coordination structure and highly exposed active sites for efficient ORR.

Utilizing Carbonaceous Materials Derived from [BMIM][TCM] Ionic Liquid Precursor: Dual Role as Catalysts for Oxygen Reduction Reaction and Adsorbents for Aromatics and CO2.

This work presents the synthesis of N-doped nanoporous carbon materials using the Ionic Liquid (IL) 1-butyl-3-methylimidazolium tricyanomethanide [BMIM][TCM] as a fluidic carbon precursor, employing two carbonization pathways: templated precursor and pyrolysis/activation. Operando monitoring of mass loss during pyrolytic and activation treatments provides insights into chemical processes, including IL decomposition, polycondensation reactions and pore formation. Comparatively low mass reduction rates were observed at all stages. Heat treatments indicated stable pore size and increasing volume/surface area over time. The resulting N-doped carbon structures were evaluated as electrocatalysts for the oxygen reduction reaction (ORR) and adsorbents for gases and organic vapors. Materials from the templated precursor pathway exhibited high electrocatalytic performance in ORR, analyzed using Rotating Ring-Disk electrode (RRDE). Enhanced adsorption of m-xylene was attributed to wide micropores, while satisfactory CO2 adsorption efficiency was linked to specific morphological features and a relatively high content of N-sites within the C-networks. This research contributes valuable insights into the synthesis and applications of N-doped nanoporous carbon materials, highlighting their potential in electrocatalysis and adsorption processes.

Hybrid high-performance oxygen reduction reaction Fe–N–C electrocatalyst for anion exchange membrane fuel cells

Atomically dispersed active sites and hierarchical porosity in Fe–N–C catalyst materials are essential for efficient oxygen reduction reaction (ORR) electrocatalysis and effective mass transport, respectively. However, the majority of these catalysts fail to deliver outstanding electrocatalytic activity and stumble when used as cathode materials in fuel cells. Herein, we developed a catalyst with partially transformed metallic Fe into Fe-Nx sites embedded in the carbonaceous matrix, and its excellent electrocatalytic performance is attributed to the hybrid nanoparticles and built-in Fe-Nx site structures. The optimized Fe@Fe–N–C catalyst was tested for ORR performance both ex-situ using the rotating (ring)-disk electrode technique and in an anion exchange membrane fuel cell (AEMFC). The Fe@Fe–N–C electrocatalyst exhibited remarkably enhanced ORR activity in alkaline media with a half-wave potential of 0.822 V vs. reversible hydrogen electrode (RHE) and showed the maximum power density (Pmax) of 242 mW cm−2 in an AEMFC test, surpassing the peak power density obtained from the Pt/C cathode catalyst (Pmax = 220 mW cm−2) under H2–O2 conditions. Therefore, the study provides a promising prospect for designing improved, cost-effective, and noble metal-free electrocatalysts for achieving high performance in AEMFCs.

High entropy La(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3 with tailored eg occupancy and transition metal-oxygen bond properties for oxygen reduction reaction

Forming high entropy oxide provides a feasible approach to finding a balance among moderate eg occupancy, high transition metal-oxygen (TM-O) covalency, and lattice energy, which is essential to ensure efficient and durable oxygen reduction reaction (ORR) process for perovskite lanthanide-transition metal oxides (LaTMO3). However, due to the compositional complexity, clarifying the relevance among the high entropy components, eg occupancy, TM-O properties, and ORR performance still remains a challenge. Herein, adopting the B site entropy-driven strategy, a series of LaTMO3 (TM = Cr, Mn, Fe, Co, Ni) with tunable eg occupancy and TM-O bond properties are synthesized, and the correlations between high entropy elements, eg occupancy, TM-O properties, and ORR performances are revealed quantitively based on the crystal field theory and the Phillips–Van Vechten–Levine (P–V–L) valence bond theory. High entropy La(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3 delivers a low overpotential of 493 mV (vs. 503 mV for LaMnO3) and a minuscule decline by only 1.7% (vs. 4.4% for LaMnO3) in half wave potential after 10,000 cycles, which can be associated with the tailored eg occupancy (1.06) and the significant enhancement in both TM-O covalency (4%) and lattice energy (691.75 kJ mol–1). This work not only demonstrates the prospects of high entropy LaTMO3 in the ORR field but also provides a new perspective for the quantitative analysis of the structure-activity relationship for high entropy oxide ORR catalysts.

Boron-alloyed porous network platinum nanospheres for efficient oxygen reduction in proton exchange membrane fuel cells

Alloying (or doping) non-metals with platinum (Pt) is an advanced solution for the development of high-performance Pt-based electrocatalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). Herein, we report boron (B)-alloyed Pt nanospheres (B-PtNSs) with a porous network nanostructure by a combination strategy of confinement reduction and post-boronation. B-alloying can induce effective electronic/geometric structures, strong Pt-B coordination, and lowered d-band center to weaken the binding energy of oxygenated intermediates on the Pt surface. The H2-O2 PEMFC with such a B-PtNSs/C as the cathode catalyst can reach a maximum power density of 1.49 W cm−2, about 1.28 times higher than that of Pt/C. After 30,000 voltage cycles in the range of 0.6 ∼ 0.95 V, only a 14.1 % loss of initial peak power density can be observed, while that with Pt/C declines 45.7 %. Non-metals alloying with Pt-based nanostructures can enable high-performance ORR electrocatalysts for their practical application in PEMFCs.

High-Density CoSe2 Sites Embedded within 2D Porous N-Doped Carbon for High-Performance Oxygen Reduction Reaction Electrocatalysis.

Designing and fabricating efficient and stable nonprecious metal-based oxygen reduction reaction (ORR) electrocatalysts is a pressing and challenging task for the pursuit of sustainable new energy devices. Herein, porous P-CoSe2@NC electrocatalysts with high-density carbon-coated CoSe2 sites were successfully fabricated based on a pyridyl-porphyrinic metal-organic framework (Co-TPyP MOF) via a molten salt-assisted synthesis method. The hierarchical pore and N-doping carbon substrate of P-CoSe2@NC promotes mass transfer and electron-transfer efficiency, which is beneficial to maximize CoSe2 site utilization. Well-designed P-CoSe2@NC exhibits efficient ORR catalytic activity with a high half-wave potential of 0.863 V and excellent catalytic stability. Meanwhile, rechargeable aqueous primary/quasi-solid-state ZABs based on a P-CoSe2@NC air cathode show a high peak power density and exceptional operating stability, catering to the demands of practical applications. The qualified performance and structure stability of the electrocatalytic system may be mainly attributed to the protection of the CoSe2 nanoparticle by the coated carbon layer. Given the rational design of the structure and the component of the electrocatalyst with enhanced ORR activity, we believe that this work has provided a reliable pathway to the development of high-performance transition-metal chalcogenides for energy-storage and -conversion devices.

Batch Preparation of PtCo/C for High-Performance Oxygen Reduction Reaction Based on a Continuous-Flow Microwave Pipeline Reactor

Batch Preparation of PtCo/C for High-Performance Oxygen Reduction Reaction Based on a Continuous-Flow Microwave Pipeline Reactor

Nano-engineered catalysts for high-performance oxygen reduction reaction

The efficient energy conversion of fuel cells is greatly constrained by the slow oxygen reduction reaction (ORR) kinetics, which necessitates the use of highly active metal catalysts such as platinum (Pt). The critical challenge limiting large-scale usage of Pt is the capital cost that can be addressed through a prototypical approach by embedding metal nanoparticles (NPs), e.g., Pt NPs, in the conductive framework. However, previously reported embedding approaches are sophisticated and suffer from limited yields, leading to higher chemical process costs and remaining distant from commercial viability. Here, we report a facile, cost-effective and time-efficient structural tuning approach to synthesizing ultrafine Pt NPs impregnated within a conductive and highly porous carbon framework via a microwave-assisted polyol reduction method. Pt NPs with a uniform size of ∼2.27 nm can be successfully integrated within the pores of the carbon framework, enabling homogeneous dispersion. Benefiting from these highly dispersed and ultrafine Pt NPs, the electrochemical surface area (ECSA) is improved to 142.98 m²/gPt, 2.25 times higher than that of the commercial counterpart (63.52 m²/gPt). Furthermore, our structurally optimized catalyst composite features a remarkably catalytic activity with a high half-wave potential (E1/2) of 0.895 V and an improved mass activity (MA) of 0.2289 A/mgPt, 2.39-fold improvement compared to the commercial counterpart. In addition, orthogonal experiments were designed to identify the key process parameters for fabricating Pt/C catalysts, offering insights for scaled-up and industrial production.

Design strategies towards transition metal single atom catalysts for the oxygen reduction reaction – A review

The electrochemical oxygen reduction reaction (ORR) is pivotal in energy conversion <i>via</i> a 4e⁻ ORR pathway and green hydrogen peroxide production <i>via</i> 2e⁻ ORR pathway. Transition metal single atom catalysts (TM SACs) have attracted intense attention in recent years for ORR due to their high activity and near maximum metal atom utilization. The future development of TM SACs for ORR requires improved understanding of reaction pathways, since currently the true origin of activity remains contentious owing to the lack of qualitative/quantitative information about active sites. Knowledge-guided design is imperative for the optimization of TM SACs performance in terms of activity and selectivity. This review focuses on the latest progress in the design of TM SACs for ORR, placing particular attention on efforts to elucidate reaction mechanisms. Experimental evidence based on <i>in-situ/operando</i> characterization measurements, along with theoretical predictions, are summarized to deepen understanding of the structure-performance relationships at both atomic and molecular level. Finally, some perspectives are offered relating to the fundamental science needed for TM SACs to find practical application in energy storage and conversion devices. We hope this review will inspire the development of new synthetic routes towards high-performance ORR electrocatalysts for the energy sector.

Simultaneously Geometrical and Electronic Modulation of L10-PtZn by Trace Ge Boosts High-performance Oxygen Reduction Reaction.

Developing a highly active, durable, and low-platinum-based electrocatalyst for the cathodic oxygen reduction reaction (ORR) is for breaking the bottleneck of large-scale applications of proton exchange membrane fuel cells (PEMFCs). Herein, ultrafine PtZn intermetallic nanoparticles with low Pt-loading and trace germanium (Ge) involvement confined in the nitrogen-doped porous carbon (Ge-L10-PtZn@N-C) are reported. The Ge-L10-PtZn@N-C exhibit superior ORR activity with a mass activity of 3.04 A mg-1 Pt and specific activity of 4.69mA cm-2, ≈12.2- and 10.2-times improvement compared to the commercial Pt/C (20%) at 0.90V in 0.1m KOH. The cathodic catalyst Ge-L10-PtZn@N-C assembled in the PEMFC shows encouraging peak power densities of 316.5 (at 0.86V) and 417.2mW cm-2 (at 0.91V) in alkaline and acidic fuel-cell, respectively. The combination of experiment and density functional theory calculations (DFT) results robustly reveal that the participation of trace Ge can not only trigger a "growth site locking effect" to effectively inhibit nanoparticle growth, bring miniature nanoparticles, enhance dispersion uniformity, and achieve the exposure of the more electrochemical active site, but also effectively modulates the electronic structure, hence optimizing the adsorption/desorption of the oxygen intermediates.

Water hyacinth root derived hybrid metal oxides/nitrogen doped porous carbon as an efficient non-precious metal oxygen reduction reaction electrocatalyst in alkaline media

A biomass derived hybrid metal oxides/nitrogen doped porous carbon (NC) electrocatalyst is fabricated by direct pyrolysis of the water hyacinth root (WHR) mixed ZnCl2 raw materials at 600 °C (WHR600), 700 °C (WHR700) and 800 °C (WHR800) under autogenic pressure conditions. XRD analysis presents a novel Zn(Al1.8Fe0.2)O4 compound combined with hematite quart and muscovite phases for WHR700 and WHR800 samples. In addition, the WHR700 sample accounts for the maximum pyridinic N content incorporated into carbon framework (NC). Electrochemically, the WHR700 catalyst displays the highest oxygen reduction reaction (ORR) performance in alkaline media. The high ORR performance for WHR700 catalyst is significantly a result of the presence of the Zn(Al1.8Fe0.2)O4 phase and the pyridinic N species. Furthermore, an accelerate durability test for WHR700 sample over 5000 cycles exhibits only 8 mV half-wave potential reduction. The WHR700 catalyst is also extremely stable to the methanol poisoning during ORR operation.

Trifunctional electrocatalysts of single transition metal atom doped g-C4N3 with high performance for OER, ORR and HER

With the rapid development of renewable energy technologies, the quest for efficient and cost-effective trifunctional catalysts capable of simultaneously driving the Hydrogen Evolution Reaction (HER), Oxygen Reduction Reaction (ORR), and Oxygen Evolution Reactions (OER) has become a focal point of research. In this study, we employed first-principles calculations to investigate the catalytic activities of the synthetic material g-C4N3 as an electrocatalyst for HER, OER, and ORR by incorporating various transition metal atoms into the numerous 3 N vacancies (TM@g-C4N3) naturally occurring in its primitive structure. Our calculations reveal that Cu@g-C4N3 holds promise as a trifunctional electrocatalyst, exhibiting low OER/ORR overpotentials (ηOER = ηORR = 0.44 V) and a |ΔG∗H| value of only 0.08 eV. Furthermore, Ni@g-C4N3_S1N2 exhibits a lower OER overpotential (ηOER = 0.34 V). Bader charge analysis, charge density difference calculations, and D-band center investigations confirm that the catalytic performance is fundamentally rooted in the electronic properties of these materials. Thus, g-C4N3 embedded with transition metal atoms shows promise as an efficient electrocatalyst for OER/ORR/HER, with implications for the development of high-efficiency trifunctional electrocatalysts.

Nitrogen-doped carbon/graphitic CQDs composites with 98.8% microporosity as a highly stable electrocatalyst for oxygen reduction

Designing micropore-rich carbon materials with large specific surface area (SSA) as a carbon-based oxygen reduction reaction (ORR) electrocatalyst is still frontier but remains challenging in catalysis of zinc-air batteries. Here we propose a new strategy for synthesis of nitrogen atoms co-doped carbon sheets and carbon quantum dots (N-C@CQDs) with an SSA of 1485.3 m2 g−1 and 98.8 % micro-porosity from α-cellulose via using a complex salt (ZnCl2-NH4Cl) with low eutectic point (179 °C) as a pore regulator and K2FeO4 as a graphitization catalyst, which can serve as an active and stable carbon-based ORR electrocatalyst. The role of K2FeO4 not only promotes graphitization but also oxidizes the large-sized graphitic carbon particles into a huge amount of uniformly distributed CQDs. This catalyst has exhibited a comparable ORR activity and superior stability to the Pt/C, but a Zn-air battery assembled with the former has delivered a higher peak power density (214 mW cm−2) and a larger gravimetric energy density (ED) of (959 Wh kgZn-1), especially in which it also displays an outstanding catalytic durability with 98.7 % ED retention during a ∼110 h continuous discharge. This work provides a new pathway for design of high-performance carbon-based ORR catalysts in various energy devices.