Two-electron Oxygen Reduction Reaction Research Articles

Selective oxygen-doping in self-supportive carbon electrode by electrochemical oxidation for electrocatalytic synthesis of hydrogen peroxide

We report the selective introduction of oxygen-containing functional groups for two-electron oxygen reduction reaction (2e-ORR) in self-supportive carbon electrode using electrochemical oxidation method. The optimal electrode shows hydrogen peroxide (H2O2) selectivity up to 95 %. CO is found active to control 2e-ORR selectivity and mechanism of oxygen species variation is elucidated by in situ infrared reflection absorption spectroscopy. We further improve mass transfer by introducing highly interconnected macropores in electrode, which shows H2O2 yield of 144 mmol cm−2 h−1 and Faradaic efficiency of nearly 100 %. These may inspire advanced active electrode creation for applications through selective electrochemical doping and structural design.

Construction of integrated oxygen-rich carbon-based metal-free cathode to simultaneous boost wastewater treatment performance and energy recovery in bio-electro-Fenton system

Fenton coupled microbial fuel cells (MFCs) used for antibiotic pollution purification are limited by energy recovery and metal leakage of electrode. Here, we constructed a two-compartment bio-electro-Fenton (MFC-Fenton) with biological anode and Fenton cathode, which using carbon nanotube based on carbon brushes (OCNT-80/CB) with active centers rich in oxygen-containing functional groups as metal-free cathode. The results show that C = O locked environmental oxygen in the cathode can in-situ use the electrons produced by the anode through two-electron oxygen reduction reaction (2e− ORR) synthesize H2O2. •OH is further generated under activation of H2O2, achieving effective degradation of tetracycline (TC) in the cathode chamber. This study breaks through the limitations of poor pH adaptability and environmental secondary pollution caused by metal dissolution. Moreover, with the advantageous features of oxygen-containing functional groups active centers, good conductivity, and cyclic stability, the OCNT-80/CB achieves a maximum power density increased by 79.4 % as compared to that of the CB control. More notably, Microbial analysis further indicated that OCNT-80/CB electrode could simultaneously enhance Proteobacteria and Firmicutes abundance in bioanode. Dominant bacteria can self-metabolize environmental wastewater generate and recycle green energy. This study proved that careful structural design of cathode could promote the electrode performance. MFC-Fenton can be a competitive technology to enhance wastewater treatment and energy recovery simultaneously.

Preparation of nitrogen-doped carbon pyrolyzed from ZIF-8 and its performance in electrocatalytic oxygen reduction to hydrogen peroxide

As an environment-friendly strategy, electrocatalytic hydrogen peroxide (H2O2) generation via two-electron oxygen reduction reaction (2e– ORR) has attracted significant scientific and technological attention. Nevertheless, limited to the low catalytic activity and high cost of noble metal-containing catalysts, forging desired electrocatalysts with high catalytic activity, low cost, and sustainability is still challenging. In this work, nitrogen doped porous carbon materials named p-ZIF-800 and p-ZIF-950 were obtained by pyrolysis of zeolitic imidazolate framework-8 (ZIF-8) nanocrystals at 800 °C and 950 °C, respectively. Then, they were employed as a catalytic layer in the gas diffusion electrodes p-ZIF-n/Ni/CB (n = 800 °C or 950 °C, CB = acetylene black). The production rates of H2O2 are up to 1.18 mg h−1 cm−2 and 1.25 mg h−1 cm−2 for p-ZIF-800/Ni/CB and p-ZIF-950/Ni/CB, respectively. Noticeably, although p-ZIF-800 had a lower degree of graphitization the difference in catalytic activity between p-ZIF-800 and p-ZIF-950 is negligible. This can be construed as a higher total nitrogen and richer mesoporous structure in p-ZIF-800 than in p-ZIF-950. Under optimized conditions of an electrode spacing of 3 cm, a pH value of 6.5, and a current density of 7.5 mA cm−2, the H2O2 production rate of p-ZIF-800/Ni/CB in the “floating-cathode” cell is up to as high as 2.09 mg h−1 cm−2, which is about 3.3 times higher than that of the cell with the “submerged-cathode” under aeration and stirring. Also, the p-ZIF-800/Ni/CB cathode demonstrates remarkable stability, it maintains its structure without losing catalytic activity after 5 catalytic cycle experiments. These results indicate that the state-of-the-art pyrolysis-based nitrogen-doped porous carbon materials exhibit a high potential for the advanced electrocatalyst of H2O2 electrogeneration.

Electron-hole separation and microcell-activated peroxymonosulfate driven by Mo/ZnO/NiF@GO/ZnFe2O4/CC dual electrodes for photocatalytic oxidation degradation of tetracycline hydrochloride

Mo/ZnO/NiF@GO/ZnFe2O4/CC photo-electrochemical catalyzed oxidation system was developed for efficiently degrading tetracycline hydrochloride (TC-HCl) by enhanced photocatalytic action. Multifunctional dual electrodes served as oxidation interface and electron transport medium exhibited inconsistent morphology, promoting more catalytic reactions at active sites, photo-electro-catalytic activity and exchange current density of the novel electrodes prepared by hydro-deposition were revealed by Cyclic Voltammetry, Electrochemical Impedance Spectroscopy and Linear sweep voltammetry techniques. indicating the photoanode approximation to two-electron Oxygen Reduction Reaction at a voltage of about 0.11 V, thus producing H2O2 with oxidizing properties. Constructed system assisted by dual electrodes achieved efficient separation of electron-hole and microcell-activated peroxymonosulfate (PMS). Experimental results demonstrated the remarkable efficiency of the system (＞ 97.0 % for 20 mg/L TC-HCl in 20 min) under optimized conditions (0.2 mM PMS, R = 1800 Ω).The reusability and stability of the system are verified by cyclic experiments. The abiotic toxicity of the intermediates was analyzed and speculated, and the recommended degradation pathways and mechanisms of TC-HCl were elucidated. The experimental system is stable, efficient and an environmentally friendly method for pollution treatment.

B–F dual-doped carbon nanotubes for multi-site and high-rate two-electron oxygen reduction reaction electrocatalysis

Electrocatalytic two-electron oxygen reduction reaction (2e−-ORR) to produce hydrogen peroxide (H2O2) is a promising green way to replace the conventional anthraquinone reaction. Non-metallic catalysts are considered as low-cost catalysts due to their excellent stability and versatile surface chemistry. The performance of non-metallic electrocatalysts is usually limited by the limited catalytic active sites on the surface. Here, we report fluorine and boron dual-doped carbon nanotubes (B–F–C) as a metal-free electrocatalyst for H2O2 production, fabricated via a fast microwave treatment. With the synergistic effect of F and B, this strategy can effectively convert carbon and boron atoms on carbon nanotubes into highly active sites. As a result, an H2O2 yield up to 24.3 mol g−1 L−1 is achieved over B–F–C with a stable selectivity of above 90% within 0.2–0.7 V vs. RHE in 0.1 M KOH. Density functional theory (DFT)calculations further confirm that the multiple active sites created by the dual doping of fluorine and boron are the key factor in improving the performance of 2e−-ORR electrocatalysis. Therefore, this work offers a promising prospect for the design and preparation of catalysts with high catalytic activity for H2O2 production and other catalytic areas of industrial significance.

Cation Effects on the Acidic Oxygen Reduction Reaction at Carbon Surfaces.

Hydrogen peroxide (H2O2) is a widely used green oxidant. Until now, research has focused on the development of efficient catalysts for the two-electron oxygen reduction reaction (2e- ORR). However, electrolyte effects on the 2e- ORR have remained little understood. We report a significant effect of alkali metal cations (AMCs) on carbons in acidic environments. The presence of AMCs at a glassy carbon electrode shifts the half wave potential from -0.48 to -0.22 VRHE. This cation-induced enhancement effect exhibits a uniquely sensitive on/off switching behavior depending on the voltammetric protocol. Voltammetric and in situ X-ray photoemission spectroscopic evidence is presented, supporting a controlling role of the potential of zero charge of the catalytic enhancement. Density functional theory calculations associate the enhancement with stabilization of the *OOH key intermediate as a result of locally induced field effects from the AMCs. Finally, we developed a refined reaction mechanism for the H2O2 production in the presence of AMCs.

Engineering Co-N-Cr Cross-Interfacial Electron Bridges to Break Activity-Stability Trade-Off for Superdurable Bifunctional Single Atom Oxygen Electrocatalysts.

Atomically dispersed metal-nitrogen-carbon (M-N-C) catalysts have exhibited encouraging oxygen reduction reaction (ORR) activity. Nevertheless, the insufficient long-term stability remains a widespread concern owing to the inevitable 2-electron byproducts, H2O2. Here, we construct Co-N-Cr cross-interfacial electron bridges (CIEBs) via the interfacial electronic coupling between Cr2O3 and Co-N-C, breaking the activity-stability trade-off. The partially occupied Cr 3d-orbitals of Co-N-Cr CIEBs induce the electron rearrangement of CoN4 sites, lowering the Co-OOH* antibonding orbital occupancy and accelerating the adsorption of intermediates. Consequently, the Co-N-Cr CIEBs suppress the two-electron ORR process and approach the apex of Sabatier volcano plot for four-electron pathway simultaneously. As a proof-of-concept, the Co-N-Cr CIEBs is synthesized by the molten salt template method, exhibiting dominant 4-electron selectively and extremely low H2O2 yield confirmed by Damjanovic kinetic analysis. The Co-N-Cr CIEBs demonstrates impressive bifunctional oxygen catalytic activity (▵E=0.70 V) and breakthrough durability including 100 % current retention after 10 h continuous operation and cycling performance over 1500 h for Zn-air battery. The hybrid interfacial configuration and the understanding of the electronic coupling mechanism reported here could shed new light on the design of superdurable M-N-C catalysts.

Boosting excitons dissociation in defective-rich graphitic carbon nitride for efficient hydrogen peroxide photosynthesis and on-site environmental governance

Solar-driven hydrogen peroxide (H2O2) production offers a sustainable strategy to address the ever-growing demand of eco-friendly oxidant and clean fuel, while its efficiency highly relies on the generation of desired reactive oxygen species (ROSs). Herein, we demonstrate that introducing boron-nitrogen vacancy (B-NV) associates in g-C3N4 enables to weaken the robust excitonic effect and promote bound excitons spontaneously dissociating into free charge carriers under ambient conditions. Specifically, the doped B atoms introduced a donor state below the conduction band of g-C3N4, which disturbs charge distribution around heptazine rings and further destabilizes excitons. The concomitant NV, serving as an accepter state locating above the valence band, cooperates with the doped B atoms to form B-NV associates that simultaneously downshifts the conduction band and valence band of g-C3N4. Distinct from the counterpart preferring to activate O2 into 1O2 via an energy-transfer-involved pathway, g-C3N4 featuring with B-NV associates displayed a superior photoactivity of visible-light-driven two-electron oxygen reduction reaction for H2O2 production with a yield of 182 μmol h−1 and selectivity of 100%. The produced H2O2 could effectively degrade organic contaminants and kill typical bacteria. This study highlights the importance of ROSs generation in two-dimensional photocatalysts for sustainable solar-to-chemical conversion and on site environmential governance.

Hydrogen Peroxide Electrosynthesis in a Strong Acidic Environment Using Cationic Surfactants.

The two-electron oxygen reduction reaction (2e--ORR) can be exploited for green production of hydrogen peroxide (H2O2), but it still suffers from low selectivity in an acidic electrolyte when using non-noble metal catalysts. Here, inspired by biology, we demonstrate a strategy that exploits the micellization of surfactant molecules to promote the H2O2 selectivity of a low-cost carbon black catalyst in strong acid electrolytes. The surfactants near the electrode surface increase the oxygen solubility and transportation, and they provide a shielding effect that displaces protons from the electric double layer (EDL). Compared with the case of a pure acidic electrolyte, we find that, when a small number of surfactant molecules were added to the acid, the H2O2 Faradaic efficiency (FE) was improved from 12% to 95% H2O2 under 200 mA cm-2, suggesting an 8-fold improvement. Our in situ surface enhanced Raman spectroscopy (SERS) and optical microscopy (OM) studies suggest that, while the added surfactant reduces the electrode's hydrophobicity, its micelle formation could promote the O2 gas transport and its hydrophobic tail could displace local protons under applied negative potentials during catalysis, which are responsible for the improved H2O2 selectivity in strong acids.

Carbon Catalysts Empowering Sustainable Chemical Synthesis via Electrochemical CO2 Conversion and Two-Electron Oxygen Reduction Reaction.

Carbon materials hold significant promise in electrocatalysis, particularly in electrochemical CO2 reduction reaction (eCO2 RR) and two-electron oxygen reduction reaction (2e- ORR). The pivotal factor in achieving exceptional overall catalytic performance in carbon catalysts is the strategic design of specific active sites and nanostructures. This work presents a comprehensive overview of recent developments in carbon electrocatalysts for eCO2 RR and 2e- ORR. The creation of active sites through single/dual heteroatom doping, functional group decoration, topological defect, and micro-nano structuring, along with their synergistic effects, is thoroughly examined. Elaboration on the catalytic mechanisms and structure-activity relationships of these active sites is provided. In addition to directly serving as electrocatalysts, this review explores the role of carbon matrix as a support in finely adjusting the reactivity of single-atom molecular catalysts. Finally, the work addresses the challenges and prospects associated with designing and fabricating carbon electrocatalysts, providing valuable insights into the future trajectory of this dynamic field.

Mesoporous carbon spheres with programmable interiors as efficient nanoreactors for H2O2 electrosynthesis

The nanoreactor holds great promise as it emulates the natural processes of living organisms to facilitate chemical reactions, offering immense potential in catalytic energy conversion owing to its unique structural functionality. Here, we propose the utilization of precisely engineered carbon spheres as building blocks, integrating micromechanics and controllable synthesis to explore their catalytic functionalities in two-electron oxygen reduction reactions. After conducting rigorous experiments and simulations, we present compelling evidence for the enhanced mass transfer and microenvironment modulation effects offered by these mesoporous hollow carbon spheres, particularly when possessing a suitably sized hollow architecture. Impressively, the pivotal achievement lies in the successful screening of a potent, selective, and durable two-electron oxygen reduction reaction catalyst for the direct synthesis of medical-grade hydrogen peroxide disinfectant. Serving as an exemplary demonstration of nanoreactor engineering in catalyst screening, this work highlights the immense potential of various well-designed carbon-based nanoreactors in extensive applications.

In Situ Generation of H2O2 over MoOx Decorated on Cu2O@CuO Core-Shell Particle Nanoarchitectonics for Boosting Photocatalytic Oxidative Desulfurization.

Photocatalytic oxidation desulfurization (PODS) has emerged as a promising, ecofriendly alternative to traditional, energy-intensive fuel desulfurization methods. Nevertheless, its progress is still hindered due to the slow sulfide oxidation kinetics in the current catalytic systems. Herein, we present a MoOx decorated on a Cu2O@CuO core-shell catalyst, which enables a new, efficient PODS pathway by in situ generation of hydrogen peroxide (H2O2) with saturated moist air as the oxidant source. The photocatalyst delivers remarkable specific activity in oxidizing dibenzothiophene (DBT), achieving a superior rate of 7.8 mmol g-1 h-1, while maintaining a consistent performance across consecutive reuses. Experimental investigations reveal that H2O2 is produced through the two-electron oxygen reduction reaction (ORR), and both H2O2 and the hydroxyl radicals (•OH) generated from it act as the primary reactive species responsible for sulfide oxidation. Importantly, our catalyst accomplishes complete PODS of real diesel fuel, underscoring an appealing industrial prospect for our photocatalyst.

Recent progress in two-dimensional materials for generation of hydrogen peroxide by two-electron oxygen reduction reaction

Hydrogen peroxide (H2O2) is an important green oxidant with a wide range of applications in wastewater treatment, pulp bleaching and chemical synthesis. In recent years, two-electron oxygen reduction reaction (2e-ORR) is expected to be a greener and safer alternative to the more energy-intensive and also carcinogenic anthraquinone process. Among the various electrocatalysts for 2e-ORR, two-dimensional nanomaterials have special advantages in the electrosynthesis of H2O2 due to their large specific surface area, abundant basal and edge sites, and tunable atomic structure. This review article summarizes the synthesis methods, and the strategies and mechanisms for enhancing 2e-ORR properties of 2D materials. Practical problems and serious challenges faced by 2D nanomaterials in the synthesis and 2e-ORR applications are elaborated. The aim of this review is to provide researchers with an understanding of 2D nanomaterials in electrocatalytic applications and to promote the further development of novel 2D nanoelectrocatalytic materials.

Single-Atom Co─O4 Sites Embedded in a Defective-Rich Porous Carbon Layer for Efficient H2O2 Electrosynthesis.

The production of hydrogen peroxide (H2O2) via the two-electron electrochemical oxygen reduction reaction (2e- ORR) is an essential alteration in the current anthraquinone-based method. Herein, a single-atom Co─O4 electrocatalyst is embedded in a defective and porous graphene-like carbon layer (Co─O4@PC). The Co─O4@PC electrocatalyst shows promising potential in H2O2 electrosynthesis via 2e- ORR, providing a high H2O2 selectivity of 98.8% at 0.6V and a low onset potential of 0.73V for generating H2O2. In situ surface-sensitive attenuated total reflection Fourier transform infrared spectra and density functional theory calculations reveal that the electronic and geometric modification of Co─O4 induced by defective carbon sites result in decreased d-band center of Co atoms, providing the optimum adsorption energies of OOH* intermediate. The H-cell and flow cell assembled using Co─O4@PC as the cathode present long-term stability and high efficiency for H2O2 production. Particularly, a high H2O2 production rate of 0.25molg-1 cath-1 at 0.6V can be obtained by the flow cell. The in situ-generated H2O2 can promote the degradation of rhodamine B and sterilize Staphylococcus aureus via the Fenton process. This work can pave the way for the efficient production of H2O2 by using Co─O4 single atom electrocatalyst and unveil the electrocatalytic mechanism.

Carboxylated Hexagonal Boron Nitride/Graphene Configuration for Electrosynthesis of High-Concentration Neutral Hydrogen Peroxide.

The electrosynthesis of hydrogen peroxide (H2 O2 ) via two-electron (2e- ) oxygen (O2 ) reduction reaction (ORR) has great potential to replace the traditional energy-intensive anthraquinone process, but the design of low-cost and highly active and selective catalysts is greatly challenging for the long-term H2 O2 production under industrial relevant current density, especially under neutral electrolytes. To address this issue, this work constructed a carboxylated hexagonal boron nitride/graphene (h-BN/G) heterojunction on the commercial activated carbon through the coupling of B, N co-doping with surface oxygen groups functionalization. The champion catalyst exhibited a high 2e- ORR selectivity (>95 %), production rate (up to 13.4 mol g-1 h-1 ), and Faradaic efficiency (FE, >95 %). The long-term H2 O2 production under the high current density of 100 mA cm-2 caused the cumulative concentration as high as 2.1 wt %. The combination of in situ Raman spectra and theoretical calculation indicated that the carboxylated h-BN/G configuration promotes the adsorption of O2 and the stabilization of the key intermediates, allowing a low energy barrier for the rate-determining step of HOOH* release from the active site and thus improving the 2e- ORR performance. The fast dye degradation by using this electrochemical synthesized H2 O2 further illustrated the promising practical application.

High effective generation of hydrogen peroxide by adjusting three-phase interfaces of gas diffusion electrode during the oxygen reduction reaction

Mass transfer of oxygen is a critical issue in the two-electron oxygen reduction reaction (2e− ORR) for the generation of hydrogen peroxide (H2O2). In this study, a novel constant velocity gas diffusion electrode (CVGDE) that can control the gas flow rate through the catalyst layer was fabricated, and the effect of the gas flow rate on three-phase interfaces (TPIs) formation and the mass transfer of oxygen in gas diffusion electrode (GDE) was investigated. In CVGDE, oxygen mass transfer was significantly improved, and the yield of H2O2 reached up to 73.65 mg cm−2 h−1 at 200 mA cm−2, which was 74.3 % higher than that of conventional GDE. Furthermore, the oxygen utilization efficiency of CVGDE reached 22.4 %, and the aeration energy consumption was decreased to 5.48 Wh kg−1, which was 1000 times less than the energy consumption required for H2O2 electrosynthesis. The experiments and theoretical calculations showed that the dynamic equilibrium state of TPI was achieved by the influence of both the electric field and air flow in the catalyst layer, which leading to a substantial increase in oxygen mass transfer and H2O2 yield. Finally, CVGDE was utilized in the electro-Fenton process for the degradation of organic contaminants. This study will contribute to the understanding of the oxygen mass transfer process in GDE.

Sn Bulk Phase Doping and Surface Modification on Ti4 O7 for Oxygen Reduction to Hydrogen Peroxide.

Developing stable and highly selective two-electron oxygen reduction reaction (2e- ORR) electrocatalysts for producing hydrogen peroxide (H2 O2 ) is considered a major challenge to replace the anthraquinone process and achieve a sustainable green economy. Here, we doped Sn into Ti4 O7 (D-Sn-Ti4 O7 ) by simple polymerization post-calcination method as a high-efficiency 2e- ORR electrocatalyst. In addition, we also applied plain calcination after the grinding method to load Sn on Ti4 O7 (L-Sn-Ti4 O7 ) as a comparison. However, the performance of L-Sn-Ti4 O7 is far inferior to that of the D-Sn-Ti4 O7 . D-Sn-Ti4 O7 exhibits a starting potential of 0.769 V (versus the reversible hydrogen electrode, RHE) and a high H2 O2 selectivity of 95.7 %. Excitingly, the catalyst can maintain a stable current density of 2.43 mA ⋅ cm-2 for 3600 s in our self-made H-type cell, and the cumulative H2 O2 production reaches 359.2 mg ⋅ L-1 within 50,000 s at 0.3 V. The performance of D-Sn-Ti4 O7 is better than that of the non-noble metal 2e- ORR catalysts reported so far. The doping of Sn not only improves the conductivity but also leads to the lattice distortion of Ti4 O7 , further forming more oxygen vacancies and Ti3+ , which greatly improves its 2e- ORR performance compared with the original Ti4 O7 . In contrast, since the Sn on the surface of L-Sn-Ti4 O7 displays a synergistic effect with Tin+ (3≤n≤4) of Ti4 O7 , the active center Tin+ dissociates the O=O bond, making it more inclined to 4e- ORR.

Theoretical study of Au–NX–C catalysts for H2O2 electrosynthesis via two-electron oxygen reduction reaction

Single-atom catalysts demonstrate remarkable activity and selectivity in H2O2 electrosynthesis via two-electron oxygen reduction reaction (ORR).

Highly coordinative molecular cobalt-phthalocyanine electrocatalyst on an oxidized single-walled carbon nanotube for efficient hydrogen peroxide production.

H2O2 production via the two-electron oxygen reduction reaction (2e- ORR) offers a potential alternative to the current anthraquinone method owing to its efficiency and environmental friendliness. However, it is necessary to determine the structures of electrocatalysts with cost-effectiveness and high efficiency for future industrialization demand. Herein, a supramolecular catalyst composed of cobalt-phthalocyanine on a near-monodispersed and oxidized single-walled carbon nanotube (CoPc/o-SWCNT) was synthesized via a solution self-assembly method for catalyzing the 2e- ORR for H2O2 electrosynthesis. Benefiting from the enhanced intermolecular interaction by introducing oxygen functional groups on o-SWCNTs, the oxidation states of single-atom Co sites were tuned via the formation of two extra Co-O bonds. Coupled with structural characterizations, density-functional theory (DFT) calculations reveal that the depressed d-band center of the Co site regulated by two axially-bridged O atoms gives rise to a suitable binding strength of oxygen intermediates (*OOH) to favor the 2e- ORR. Thus, the CoPc-6wt%/o-SWCNT-2 catalyst with optimized synthetic parameters delivers competitive 2e- ORR performance for H2O2 electrosynthesis in a neutral electrolyte (pH = 7), including enhanced H2O2 generation, satisfactory molar selectivity of ∼83-95% and long-period stability (75 h) in H-cell measurement. Moreover, it could also be boosted to show a high current of 45 mA cm-2, recorded turnover frequency of 25.3 ± 0.5 s-1 and maximum H2O2 production rate of 5.85 mol g-1 h-1 with a continuous H2O2 accumulation of 1.2 wt% in a flow-cell device, which outperformed most of the reported neutral-selective nonprecious metal single-atom catalysts.

Recent advances in the electrochemical production of hydrogen peroxide

Hydrogen peroxide (H2O2) is an innovative and environmentally friendly oxidant that finds wide-ranging applications across multiple industries. In the past, H2O2 production predominantly relied on the anthraquinone method, which had drawbacks such as the generation of organic waste and the requirement for energy-intensive reactions. A cheap, efficient, and sustainable way of producing H2O2 may be achieved through the redox reaction between oxygen and water. On both small and large scales, the electrosynthesis of H2O2 is practical and affordable. In recent years, it has been thought that the energy-intensive anthraquinone process may be replaced by the electrochemical synthesis of H2O2 via the two-electron oxygen reduction reaction (ORR) route. To eliminate the organic pollutants found in drinking water and industrial effluent, highly effective hydrogen peroxide (H2O2) must be produced electrochemically using gas diffusion electrodes (GDEs). Compared to other carbonaceous cathodes, the GDEs as cathodic electrocatalysts demonstrate greater cost-effectiveness, lower energy consumption, and higher oxygen utilization efficiency for the formation of H2O2. A promising alternative for enabling the growth of sustainable economics in the W&W sector is microbial electrochemical systems (MESs) that create H2O2. To enhance the efficiency and predictability of H2O2 production in MESs, a machine-learning approach was adopted, incorporating a meta-learning methodology to forecast the generation rate of H2O2 in MES based on the seven input variables, comprising several design and operational parameters.