ABSTRACT Iron–nitrogen co‐doped carbon catalysts have attracted considerable attention in proton exchange membrane fuel cells (PEMFCs) due to their comparable oxygen reduction reaction (ORR) activity to the widely used commercial Pt/C. However, their practical application is hindered by insufficient long‐term stability. Herein, we report an Fe─N─C catalyst with a nitrogen‐doped bilayer‐like graphitic carbon architecture, denoted as Fe SA ‐Fe AC /N‐tBLG. Through a melamine‐assisted interlayer‐selective assembly and nitrogen‐rich spatial confinement strategy, Fe single atoms (Fe SAs ) are primarily stabilized in the ZIF‐8‐derived inner carbon layer enriched with Fe─N coordination sites, whereas Fe atomic clusters (Fe ACs ) are preferentially formed within or near the melamine‐derived outer nitrogen‐doped carbon layer. This spatially coupled configuration enhances the resistance of Fe SAs against dissolution. Moreover, the outer‐layer Fe ACs modulate the local magnetic environment and induce a favorable spin‐state transition in the inner‐layer Fe SAs from low‐spin to medium‐spin. This spin‐state transition could optimize the electronic structure of the active sites for ORR catalysis. Benefiting from enhanced resistance to dissolution and the spin‐state modulation of the inner‐layer Fe SAs , the as‐prepared Fe SA ‐Fe AC /N‐tBLG cathode catalyst enables an H 2 ‐air single PEMFC to deliver a peak power density of 647 mW cm −2 . It also maintains approximately 90% of its initial peak power density after 30,000 cycles of accelerated stress testing. This work provides theoretical and experimental insights into the design of metal–nitrogen–carbon electrocatalysts with both high activity and durability.

Developing highly active and durable nonprecious-metal catalysts for acidic oxygen evolution reaction (OER) is crucial for optimizing hydrogen production in proton exchange membrane water electrolysis. However, substantial challenges remain in achieving this goal. In this study, a synergistic Mn/Ni codoping strategy is proposed to fabricate a spinel-type Co2Mn0.5Ni0.5O4 (CMN) catalyst, which requires a low OER overpotential of 273 mV to reach 10 mA cm-2 and demonstrates an excellent stability for over 430 h in 0.5 M H2SO4, outperforming pristine Co3O4. This superb performance could be attributed to Mn/Ni codoping in Co3O4, which introduces structural defects, generates oxygen vacancies, and increases the Co3+/Co2+ ratio. Furthermore, differential electrochemical mass spectrometry and in situ Raman studies reveal that CMN activates an additional lattice oxygen mechanism (LOM) pathway, thus accelerating the OER rate, with quantitative analysis showing that LOM contributes approximately 22.4% to the overall reaction. Partial density of states analysis confirms that Ni effectively narrows the energy-level separation between Co 3d and O 2p orbitals, strengthens their electronic coupling, and thereby facilitates lattice oxygen activation. Additionally, Bader charge analysis confirms that Mn enhances the Mn-O bond, thereby stabilizing the crystal structure and preventing structural collapse. These findings demonstrate the potential of Mn/Ni coregulation for balancing lattice oxygen activity and structural stability in Co-based spinel catalysts.

Asymmetric ultrafine mono-mesopore architectures with ultrasmall size, an open window, and unique physicochemical properties offer great opportunities in energy storage, yet their synthesis remains challenging. Inspired by the fast, unidirectional capture ability of Nepenthes, we propose an interface-shrunk monomicelle assembly strategy to synthesize asymmetric ultrafine mono-mesopore nanoparticles (AUMNs) with an open window on hollow shells. These biomimetic nanoparticles (∼45 nm) possess a mono-mesopore cavity (∼40 nm) and an opening window (∼20 nm). Their structural parameters, including window size (15–28 nm), shell thickness (7–14 nm), and cavity size (38–59 nm), are precisely tunable. The resulting AUMNs exhibit a high surface area (1312 m² g⁻¹) and abundant pseudocapacitive sites. As cathodes in zinc-ion hybrid capacitors (ZIHCs), they show low charge-transfer impedance and deliver a maximum capacity of 210 mAh g⁻¹. Asymmetric ultrafine mono-mesopore architectures with ultrasmall size, an unimpeded opened window, and unique physicochemical properties endow great opportunities in energy storage, while their synthesis remains challenging. Here the authors propose an interface-shrunk monomicelle assembly strategy for the synthesis of asymmetric monomesopore nanoparticles architectures with an unimpeded open window on hollow shells.

Oxygen vacancy-rich bismuth vanadate (BiVO4- x) photoanodes usually exhibit excellent bulk charge separation efficiency and relatively low onset potential, but the Fermi-level pinning effect leads to a relatively low photovoltage (V ph). Herein, we propose a synergistic strategy of F element doping and in situ deposition of the NiCoBi co-catalyst to amplify the V ph of BiVO4- x. Systematic investigations demonstrate that F doping modifies the electronic structure of BiVO4- x, increases the electron work function, and synergizes with the NiCoBi co-catalyst to repair surface defect states, thereby enhancing the V ph of the F-BiVO4- x/NiCoBi photoanode by 37.78% compared to its unmodified BiVO4- x counterpart. Consequently, both organic oxidation reactions and water oxidation reactions are significantly activated. More importantly, the enhanced V p h can also improve the long-term operational stability of the photoanode. Such improvements in multiple performance metrics can provide a universal strategy for the design of next-generation photoelectrode materials.

Understanding how metal–polymer interactions in aqueous systems govern interfacial behavior is critical for controlling colloidal stability in complex particulate environments. In this study, the coordination and interfacial properties of a Cu2+–polyaspartic acid (PASP) system were systematically investigated to elucidate the molecular-level mechanisms linking solution chemistry with interfacial regulation. Results indicate that PASP readily coordinates with Cu2+ in aqueous solution through carboxyl functional groups, forming stable metal–ligand complexes via ligand exchange processes. These complexes exhibit selective interfacial activity, preferentially adsorbing onto Zn-containing surfaces through Cu-mediated bridging interactions, while showing limited affinity toward Pb-containing surfaces. FTIR and XPS analyses confirm the formation of coordination structures and their surface-specific adsorption behavior. The adsorption of Cu2+–PASP complexes leads to the formation of hydrated, negatively charged interfacial layers, significantly enhancing surface hydrophilicity and electrostatic repulsion. Zeta potential measurements and contact angle results corroborate these changes in interfacial properties. Furthermore, interaction energy calculations based on extended DLVO theory reveal a transition from net attractive to strongly repulsive interparticle forces, indicating the establishment of a substantial energy barrier against aggregation. This behavior is consistent with in-situ particle size evolution monitored by FBRM, demonstrating enhanced dispersion stability. Thermodynamically, the spontaneous formation and adsorption of Cu2+–PASP complexes are driven by coordination bonding, hydration entropy gain, and interfacial energy minimization. The combined effects of electrostatic, steric, and hydration forces contribute to the stabilization of dispersed systems.

Electrochemical H2O2 synthesis via the two-electron oxygen reduction reaction (2e– ORR) offers a green alternative to the energy-intensive anthraquinone process, but its practical viability is hindered by the sluggish and low-value oxygen evolution reaction (OER) at the anode. Here, we present an energy-saving paired electrolysis strategy that replaces anodic OER with methanol oxidation reaction (MOR) using a ternary Mn-doped NiCo layered double hydroxide (Ni0.50Co0.30Mn0.20 LDH) catalyst in situ grown on nickel foam (NF) by a one-step hydrothermal method. The optimized catalyst achieves a low MOR potential of 1.32 VRHE at 10 mA cm–2 and a formate Faradaic efficiency of 92.9%, outperforming its undoped counterpart (Ni0.61Co0.39 LDH, 1.37 VRHE and 83.3%). In-situ Raman spectroscopy and density functional theory calculations reveal that Mn doping lowers the energy barrier for the Ni2+/Ni3+ redox transition, facilitating the generation of catalytically active Ni3+ species. When coupled with graphitized hydroxyl-functionalized multi-walled carbon nanotubes coated on carbon paper (CNTs@CP) as the 2e– ORR cathode in a two-electrode electrolyzer, at the operation condition of 50 mA cm–2, the 2e– ORR||MOR system delivers a cell voltage reduction of 254 mV, enabling a 10.3% decrease in energy consumption for H2O2 production, compared with the conventional 2e– ORR||OER system. Moreover, the simultaneous generation of value-added formate at the anode yields a 97.9% increase in net economic benefit. This work establishes a generalizable paired electrolysis paradigm for the decentralized, energy-efficient, and economically viable co-production of H2O2 and high-value chemicals.

The core innovation of this study lies in the construction of an indirect glycerol oxidation coupled with hydrogen (H2) evolution system mediated by the Cu2+/Cu+ redox pathway. By leveraging the spontaneous reduction of the Cu(OH)2 pre-catalyst with glycerol, the latter is converted into high-value products such as glycerate and formate. The resulting Cu+ species are subsequently electrooxidized back to Cu2+, establishing a continuous Cu2+/Cu+ redox cycle that effectively bypasses the high overpotential limitations of traditional direct oxidation pathways. X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and operando Raman spectroscopy confirm that, under alkaline conditions, glycerol efficiently reduces Cu(OH)2 to Cu2O, ensuring the sustainability of the Cu+ electrooxidation process. This mechanism lowers the anodic onset potential to 0.65 VRHE (versus reversible hydrogen electrode), approximately 1 V below that required for OER, achieving a "low-potential-driven" reaction. A coupled Cu(OH)2/CF || Pt/C cell delivers 100 mA cm-2 at a H2 production energy demand of only 2.7 kWh m-3 H2, exceeding 50% reduction than that required in the conventional water electrolysis (5.6 kWh m-3 H2).

The solid-liquid-gas triple-phase interface in the CO2 electro-reduction reaction (CO2RR) is pivotal for determining catalytic activity and selectivity, as it influences both the kinetics and thermodynamics of the reactions. However, observing this interface in situ is challenging because it forms at the interface among the solid catalyst, the flowing electrolyte, and the turbulent CO2. To address the issues, we achieved unobstructed in situ Raman observations at the microscale by developing a straightforward catalyst-integrated gas diffusion electrode (GDE). This monolithic GDE, featuring a biomimetic hydrophobic structure, fully releases the triple-phase interface─an essential prerequisite for enabling the in situ detection. Characterizations reveal that the microenvironment at the triple-phase interface significantly enhances multicarbon (C2+) selectivity. Furthermore, using advanced in situ 3D Raman tomography, we successfully visualized the spatial distribution of the triple-phase interface with high precision. The integration of in situ Raman spectroscopy with computational modeling has provided invaluable insights into the evolution of species within the microenvironment, elucidating a high local pH and rapid CO2 mass transfer at the triple-phase interface.

NiFe-based Prussian blue analogue (PBA) derivatives have attracted significant attention as electrocatalysts for the oxygen evolution reaction (OER) in water splitting. However, efficiently in-situ constructing integrated PBA electrodes under mild synthesis conditions continues to be a great challenge. In this study, a porous honeycomb-like NiFe PBA derivative was successfully constructed on nickel foam (NF) via mild HF etching and controlled pyrolysis. Owing to the complexing corrosion between Ni and HF, the generation of Ni2+ ions will continue unabated, which promotes the nucleation of the NiFe PBAs (Ni3[Fe(CN)6]2). Simultaneously, polyvinylpyrrolidone (PVP), as a structure-directing agent, provides favorable conditions for the formation of the desired honeycomb-like product. The optimized catalyst (abbreviated as F/0.1-NiFe PBAs-300, where 0.1 and 300 represent HF concentration and pyrolysis temperature, respectively) demonstrates an outstanding OER performance with an overpotential of 273 mV at 10 mA cm-2 and excellent durability over 120 h in 1.0 M KOH aqueous solution, surpassing commercial RuO2. This work offers a feasible strategy for designing high-performance PBA-derived integrated electrode with the potential to replace noble-metal-based OER electrode.

The efficient degradation of pharmaceuticals and personal care products (PPCPs), including diclofenac (DCF), in aquatic environments remains a major challenge. Recently, electrochemically activated permanganate (E-Mn(VII)) processes have been identified as a promising approach for organic pollutants treatment, although they exhibit relatively limited oxidation efficiency with conventional electrode materials. In this study, a novel E-Mn(VII) system was developed to overcome this critical bottleneck, where activated carbon (AC) was treated through simple mechanical ball milling and employed as a functional cathode material. Ball milling induced surface oxygen functionalities and structural defects in AC, thereby enhancing electrochemical generation of H2O2 from oxygen (O2) under acidic conditions. The ball-milled AC (BMAC) electrode produced a high H2O2 yield of 398.5 mg·L-1 and achieved a current efficiency of 80–84% after 120 min. The H2O2 generated in situ facilitated the transformation of Mn(VII) to MnO2 during electrochemical activation, serving as the primary catalyst to promote DCF removal by Mn(VII) oxidation. Consequently, DCF removal exceeded 86% within 30 min under optimal conditions with a pseudo-first-order rate constant (kobs) of 0.066 min-1, over 14 times higher than that observed by Mn(VII) oxidation. Radical scavenging and chemical probe experiments confirmed the negligible contributions of reactive oxygen species (e.g. •OH, O2•–, 1O2), and soluble manganese intermediates. The system maintained satisfactory performance in complex water environments and exhibited stable electrode recyclability. Overall, our research provides a rational strategy for enhancing electrochemical Mn(VII) activation by using mechanochemically modified carbon electrodes, advancing the development of efficient and sustainable E-Mn(VII) system for water decontamination.

In order to reduce the risk of high-threat pathogens, a photocatalytic antibacterial method with a reputation for high efficiency and sustainability has attracted widespread attention. Recently, metal-organic frameworks (MOFs) have emerged as desirable platforms for photocatalytic applications by virtue of their structural diversity and functional adjustability. Herein, we report that we have synthesized a stable and photosensitive zirconium-based MOF (Zr-MOF) with a photoactive tetrathienylethene-based organic linker, Zr-TSS-1. Compared with all-carbocyclic Zr-MOF counterparts, Zr-TSS-1 shows a substantial improvement in visible-light harvesting and free-carrier generation, enabling it to be a promising candidate for photocatalytic antibacterial applications. In order to validate the advantages of this framework as an antibacterial protective material, a composite was fabricated by incorporating robust Zr-TSS-1 onto sustainably accessible bacterial cellulose (BC) using an in situ growth method. This composite exhibits near-complete lethality toward typical Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus within 1 h under mild irradiation and preserves outstanding antibacterial capability after five cycles of reutilization. In addition, the high biocompatibility is confirmed by the low cytotoxicity toward human skin fibroblast, suggesting its potential for biomedical and healthcare applications. This research demonstrates the efficacious integration of a purposely designed photosensitive porous framework onto a sustainable substrate for synergistic functionality, paving a practical way for the development of the next-generation high-efficiency antimicrobial technology.

Ensuring high electrocatalytic performance simultaneously with low or even no precious-metal usage is still a big challenge for the development of electrocatalysts toward oxygen evolution reaction (OER) in anion exchange membrane water electrolysis. Here, homogeneous high entropy oxide (HEO) film is in-situ fabricated on nickel foam (NF) substrate via magnetron sputtering technology without annealing process in air, which is composed of many spinel-structured (FeCoNiCrMo)3O4 grains with an average particle size of 2.5 nm. The resulting HEO film (abbreviated as (FeCoNiCr-Mo)3O4) exhibits a superior OER performance with a low OER overpotential of 216 mV at 10 mA cm-2 and steadily operates at 100 mA cm-2 for 200 h with a decay of only 272 mu V h-1, which is far better than that of commercial IrO2 catalyst (290 mV, 1090 mu V h-1). Tetramethylammonium cation (TMA+) probe experiment, activation energy analysis and theoretical calculations unveil that the OER on (FeCoNiCrMo)3O4 follows an adsorbate evolution mechanism pathway, where the energy barrier of rate-determining step for OER on (FeCoNiCrMo)3O4 is substantially lowered. Also, methanol molecular probe experiment suggests that a weakened *OH bonding on the (FeCoNiCrMo)3O4 surface and a rapid deprotonation of *OH, further enhancing its OER performance. This work provides a feasible solution for designing efficient high entropy oxides electrocatalysts for OER, accelerating the practical process of water electrolysis for H2 production. (c) 2025, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

Developing high-performance and cost-effective electrocatalysts for seawater oxidation is highly desirable yet remains a significant challenge. Herein, Fe-doped Ni(OH)2 with a Ni5P4 protective layer anchored on nickel foam (Fe-Ni(OH)2@Ni5P4/NF) has been successfully synthesized by partial phosphorization of nickel-iron-layered double hydroxide (LDH). The as-constructed catalyst exhibits low oxygen evolution reaction (OER) overpotentials of 260 and 265 mV at a current density of 100 mA cm-2 in alkaline water and seawater, respectively, as well as long-term durability at a high current density of 500 mA cm-2 for over 200 h toward seawater oxidation. More impressively, the Fe-Ni(OH)2@Ni5P4/NF(+)||Pt/C/NF(-) electrolyzer also exhibits an outstanding performance for overall seawater electrolysis, with a low cell voltage of 1.70 V at 100 mA cm-2 and operating steadily at 200 mA cm-2 for 100 h, outperforming the commercial RuO2/NF(+)||Pt/C/NF(-) (1.82 V at 100 mA cm-2) and most reported advanced electrocatalysts. Theoretical calculations reveal that an interfacial electronic redistribution induces a downshift of the Ni d-band center, effectively weakening *O intermediate adsorption and reducing the energy barrier for the rate-limiting *O ->*OOH transition. The desirable activity and corrosion resistance of the Fe-Ni(OH)2@Ni5P4/NF catalyst could be attributed to the plentiful exposed active sites, the interfacial interactions between hydroxides and phosphides, and a negatively charged PO4 3- anionic layer. This work provides a universal strategy for designing robust heterostructured electrocatalysts through interface engineering.

CO2 reduction reaction (CO2RR) has attracted considerable attention as a sustainable approach for carbon capture and conversion. However, the dynamic nature of electrocatalysts under operational conditions, particularly at the reaction interface, presents significant challenges for understanding reaction mechanisms and optimizing catalyst design. In situ/operando characterization techniques are crucial to understanding the reaction interfaces and mechanisms of CO2RR. This review focuses on various in situ/operando techniques employed to explore reaction interfaces, the insights derived from these studies, and their implications for catalyst design.

The conversion of nitrate pollutants by the electrocatalytic nitrate reduction reaction (NO3RR) is a desirable and sustainable strategy to alleviate the environmental crisis and obtain a high-value chemical NH3. In this work, a core-shelled CoNiCu-OH has been developed as a highly active bifunctional electrocatalyst by electrodeposition and chemical bath deposition. As a result, the CoNiCu-OH delivers a low potential of 221 mV at 10 mA cm- 2 for NO3RR and a maximum NH3 selectivity of 90.3% with a maximum Faraday efficiency of 93.3%. The remarkable activity originates from the upshift of the d-band center and the decreased energy barrier of the potentialdetermined step for enhanced catalytic activity and efficient hydrogenation process for NO3RR. Meanwhile, the CoNiCu-OH as the anodic urea oxidation reaction (UOR) electrocatalyst to replace the oxygen evolution reaction for the energy-saving NH3 production shows a slight potential of 1.332 V at 10 mA cm- 2. Subsequently, a coupling electrolyzer NO3RR/UOR based on CoNiCu-OH only requires a cell voltage of 1.63 V at 100 mA cm- 2. This work provides a promising route to design efficient bifunctional electrocatalysts and promotes NH3 production with low energy consumption.

The oxygen reduction reaction (ORR) is a critical process at the cathode of proton exchange membrane fuel cells (PEMFCs), but its slow kinetics significantly limit the overall energy conversion efficiency. Pt-based alloy catalysts remain the most effective catalysts for electrocatalyzing ORR. However, the high cost, limited reserves, and insufficient durability of Pt-based alloy catalysts pose major barriers to the widespread commercialization of PEMFCs. This review summarizes recent progress in the development of advanced Pt-based alloy ORR catalysts. Key strategies for their performance enhancement are discussed, mainly including geometric structure optimization, strain effect regulation and carrier interface modulation. Finally, we outline the current challenges and future research directions towards achieving high-performance, low-cost, and durable Pt-based alloy catalysts for next-generation fuel cells.

Metal–organic frameworks (MOFs) are potential candidates for electrocatalysis due to their well-defined, tunable structures, and ability to incorporate diverse active sites. However, their inherent insulating nature restricts electron transfer from electrode to remote active sites, leading to diminished catalytic performance. In this work, we present a novel strategy to overcome this limitation by reducing 3D MOFs (3D_MOFs) into monolayered MOFs (monoMOFs) with a thickness of ∼1.8 nm, maximizing the exposure of catalytic sites to the electrode and enhancing electrocatalytic performance. We designed and synthesized a monoMOF incorporating cobalt(II)–porphyrin sites in the linker (monoMOF-Co) for CO 2 electroreduction. After being grafted onto graphene oxide, the monoMOF-Co exhibited a peak faradaic efficiency for CO production (FE CO  = 93%), surpassing the performance of a 3D_MOF incorporating the same porphyrin–Co-based linker (3D_MOF-Co, FE CO  = 51%). Additionally, monoMOF-Co achieved a turnover frequency of 10 600 h −1 at −0.8 V versus the reversible hydrogen electrode (RHE) and maintained stability over 47 h in a near-neutral aqueous solution. In situ spectroscopic studies further confirmed the distinct electric field environment in the Stern layer between monoMOF-Co and 3D_MOF-Co. Furthermore, similar enhancement effects of monoMOFs over 3D_MOFs were observed in the nitrate and oxygen electroreduction reactions, highlighting the broader applicability of monoMOFs in electrocatalysis.

Ensuring high-quality activity of proton exchange membrane fuel cells (PEMFCs) while mitigating the degradation of Pt-based alloy catalysts remains challenging. A platinum-skinned truncated octahedral PtNi alloy with (100)/(111) facet heterostructures is synthesized through a low-temperature thermally driven etching strategy, demonstrating exceptional oxygen reduction reaction (ORR) activity and stability. The heterostructure of the Pt skin -PtNi(111) facet destabilizes the *OOH intermediate and promotes the preferential O─O bond cleavage, leading to the optimization of ORR pathway. A linear correlation between the generalized coordination number ( ) and Δ G *OH demonstrates that the facet hetero-sites optimize the adsorption of *OH to the theoretically optimal state through ligand and geometric effects. The optimized PNZC-5A160 catalyst exhibits enhanced ORR activity (2.97 A mg Pt −1 at 0.9 V vs. RHE) and superior H 2 -O 2 single PEMFC performance [mass activity (MA) of 0.5 A mg Pt −1 at 0.9 V iR-free ; peak power density of 1.42 W cm −2 , exceeding the U.S. Department of Energy 2025 targets. After accelerated stress tests, the loss in MA at 0.9 V iR-free and in potential at 0.8 A cm −2 is only 8% and 3.7 mV, respectively, due to the enhanced binding of subsurface Pt and Ni to surface Pt atoms through Pt skin, thereby inhibiting the dissolution of Pt and Ni.

Hydrazine oxidation-assisted hydrogen evolution represents a promising avenue for energy-saving hydrogen production. However, the development of bifunctional catalysts with high atom economy and durability for both hydrazine oxidation reaction (HzOR) and hydrogen evolution reaction (HER) remains challenging. Here, a design is reported that combines sulfur-stabilized Pt clusters and Ni-N4 sites on nitrogen-doped carbon support (Ptn-S/Ni1-NC) for boosting alkaline hydrazine oxidation-assisted hydrogen evolution. Experimental and theoretical results reveal that the pre-coordinated sulfur atoms on Pt clusters provide strong metal-support interaction (SMSI) for the homogeneous distribution of Pt clusters, allowing Pt clusters to remain ultrafine, which ensures high atom utilization and sufficient active sites. Moreover, the electronic interactions and synergistic adsorption mechanism of Pt clusters and adjacent Ni-N4 sites markedly accelerate the H2O dissociation and HzOR kinetics. As a result, the Ptn-S/Ni1-NC catalysts exhibit exceptional catalytic activity, achieving an ultrasmall HER overpotential of 19 mV and an ultralow HzOR working potential of -21 mV at 10 mA cm-2 current density. In addition, the overall hydrazine oxidation-assisted splitting (OHzS) electrolyzer can reach 10 mA cm-2 with a low cell voltage of 79 mV and good long-term stability in 1.0 m KOH/0.5 m N2H4.

Electrochemical two-electron water oxidation reaction (2e − WOR) driven by renewable energy offers an attractive route to produce H 2 O 2 , while the corresponding electrocatalyst still requires further improvement for the activity, selectivity, and the resulting H 2 O 2 yield. Surface-interface engineering of electrocatalysts has great potential to advance 2e − WOR performance. This review provides a succinct yet comprehensive insight into the functional mechanisms of surface-interfacial properties affecting 2e − WOR performance on electrocatalyst. The Gibbs free energy theoretical framework related to surface electronic structure and interfacial reactive kinetics mechanism related to electrolyte, electrode–electrolyte interface structure, and interfacial microenvironment properties are firstly discussed. Afterward, various surface-interface engineering strategies toward high performance electrocatalysts including the regulation of surface electronic structure, the electrode–electrolyte interface structure, and the interfacial microenvironment have been overviewed. Rational manipulations of the above surface-interfacial engineering strategies are critical to design highly efficient 2e − WOR electrocatalysts, leading to the development of the green H 2 O 2 production.