The proton exchange membrane water electrolysis (PEMWE) technology faces significant challenges in cost and stability, primarily due to the heavy reliance of the anodic oxygen evolution reaction (OER) on scarce and expensive iridium. Consequently, developing high-performance acidic OER catalysts with low platinum-group-metals (PGMs) content has emerged as a central and urgent objective in the field. This review begins with the critical bottlenecks of PEMWE and the unique economic and performance merits of W-based catalysts, then systematically outlines their latest research progress. It highlights the performance enhancement mechanisms of both PGM and PGM-free W-based catalysts, and also discusses PEMWE device optimization and advanced synthesis methods of W-based catalysts. Finally, it presents key challenges and a future perspectives for rational design of low-cost acidic OER electrocatalysts.

Multicomponent carbonate electrolytes are central to next generation electrochemical energy storage devices, and the choice of electrode model strongly shapes their predicted interfacial behavior. This study compares the constant charge method (CCM) and constant potential method (CPM) for modeling electrified interfaces in such electrolytes. Molecular dynamic simulations are performed for 1 M LiPF6 in an ethylene carbonate:dimethyl carbonate:ethyl methyl carbonate ternary carbonate electrolyte sandwiched between two graphite electrodes. Results show that CCM and CPM give nearly identical interfacial structures at low and moderate polarization, with clear deviations emerging at ±1.35 V, equivalent to a 2.70 V cell voltage. This method-dependent response originates mainly from Li+ behavior at the negative electrode, where CCM promotes partial desolvation and contact-like adsorption, whereas CPM preserves solvent separated adsorption through dynamic charge redistribution and stronger interfacial solvent ordering. Meanwhile, PF6- distributions remain comparatively insensitive to electrode treatment. This study defines the polarization regime where CCM is sufficient and establishes when CPM is required to capture coupled Li+/solvent/electrode interactions in carbonate solvent-based energy storage electrolytes.

ABSTRACT Water electrolysis is pivotal for converting renewable energy into clean hydrogen fuel, addressing global energy demand sustainably. However, the development of highly efficient and cost‐effective catalysts for the oxygen evolution reaction (OER) remains a significant challenge, particularly at the industrial scale. This report explores a newly discovered pathway, the oxide path mechanism (OPM) for OER—mechanism involving the oxide formation and evolution during the reaction, emphasizing its potential to overcome existing limitations. OPM enables direct O─O coupling without oxygen vacancies, offering superior stability. We detail both classical and innovative in‐situ characterization techniques that are central to unraveling the OER mechanism. The advanced in‐situ electrochemical techniques, such as inductively coupled plasma mass spectroscopy, X‐ray photoelectron spectroscopy, and Mössbauer spectroscopy, coupled with in‐situ structural analyses, provide crucial insights into the catalyst surface, the electrode‐electrolyte interface and the kinetics of OER. This review provides a systematic analysis integrating classical electrochemical methods with advanced in‐situ/operando techniques, specifically focusing on understanding OPM. While numerous studies have examined individual characterization methods, this study systematically integrates traditional electrochemical approaches with in‐situ and operando techniques, offering critical insights into their complementary roles in elucidating reaction pathways. The integration of these methodologies provides unprecedented understanding of catalyst behavior under operational conditions, guiding the rational design of next‐generation OER catalysts. Furthermore, we discuss essential standardized test toolkits and protocols, such as those for rotating disk electrode and membrane electrode assembly, which are vital for ensuring reproducibility and scalability in OER catalyst research.

The integration of real-time and flexible imaging has significantly advanced X-ray scintillator imaging technologies. However, combining both functionalities into a single scintillator material remains a fundamental challenge. To address this, we designed a zero-dimensional cerium (III)-based organic-inorganic hybrid halide scintillator, MPH2CeCl5 & centerdot;3H2O (MPH = morpholine), using low-cost solution processing and leveraging Ce (III)'s inherently nanosecond-scale 4f-5d transitions. La3+-alloying induced a dual effect, enhancing the photoluminescence quantum yield to 2.75 times the original value while maintaining a short decay time of approximately 22 ns. Combined with heavy-atom effects, this nanosecond-scale decay prompted investigation of X-ray scintillation performance, revealing a respectable light yield of 10,400 photons/MeV and a low detection limit of 96.73 nGyair/s. By embedding the optimized MPH2CeCl5 & centerdot;3H2O into poly(methyl methacrylate) (PMMA), we fabricated a high-performance flexible film that mitigates material hygroscopicity while enabling outstanding flexibility and dynamic imaging capabilities. This film achieved motion-artifact-free dynamic imaging at 100 fps, clearly resolving blades rotating at 560 degrees/s. This work demonstrates Ce (III)-based halide hybrids as promising platforms for advanced medical and industrial imaging, offering high light yield, rapid response, and superior processability.

Iridium-based catalysts for the acidic oxygen evolution reaction (OER) predominantly follow the adsorbate evolution mechanism (AEM), with their intrinsic activity limited by sluggish proton-transfer kinetics. Based on this, a strategy is proposed involving the construction of a discontinuous WOx interlayer incorporating isolated W single atoms and amorphous WOx clusters on supported Ir-based catalysts. The optimized Ir/W-TiN catalyst achieves current densities of 100 mA cm-2 at remarkably low overpotentials of 293 mV. Leveraging the non-lattice oxygen from the amorphous WOx, this design promotes a shift in the reaction pathway from the conventional AEM to an interface non-lattice oxygen-assisted deprotonation mechanism (IOADM), simultaneously enhancing both activity and stability. The incorporation of W species facilitates the formation of oxygen vacancies and a hydrogen-bond network, which lowers the reaction energy barrier and accelerates deprotonation kinetics. In a proton exchange membrane water electrolyzer, the membrane electrode assembly with the Ir/W-TiN anode exhibits a high current density exceeding 2.2 A cm-2 at 1.8 V. Furthermore, with a low Ir loading of 0.2 mgIr cm-2, it demonstrates excellent durability, maintaining stable operation for 2000 h at 1.0 A cm-2. This work provides new mechanistic insights for designing highly efficient, stable, and low-Ir-loaded anode catalysts via interface engineering.

Developing efficient and durable catalysts is crucial for advancing proton exchange membrane water electrolysis (PEMWE) toward sustainable hydrogen production. Ir-based catalysts are stable but limited by scarcity and cost, whereas Ru-based catalysts are more active and affordable yet unstable in acidic media due to Ru over-oxidation into soluble RuO4 species. Here, we report a heterostructured Ir/RuO2 catalyst prepared through a combination of an ultrafast high-temperature shock (HTS) process followed by a wet-chemistry deposition of Ir. The HTS method enables the ultrafast synthesis of oxygen vacancy-rich RuO2 nanoparticles accomplished in 20 s. Subsequently, uniformly dispersed 1.02 nm Ir clusters were anchored on RuO2, forming a stable Ru-O-Ir interface that enhances catalytic activity and durability. The optimized Ir/RuO2 via HTS catalysts exhibits an ultra-low overpotential of 150 mV at 10 mA cm(-2) and exceptional stability over 500 h in 0.5 M H2SO4 electrolyte. When implemented as anode membrane electrode in proton-exchange membrane water electrolysis (PEMWE), it delivers 1 A cm(-2) at 1.60 V (60 degrees C) and maintains stable operation for 100 h. In situ characterizations combined with density functional theory (DFT) calculations reveal that oxygen vacancies and strong interfacial charge transfer synergistically facilitate the adsorbate evolution mechanism (AEM) while suppressing Ru dissolution. This work demonstrates a two-step approach for constructing high-utilization-efficiency Ru-Ir catalysts with improved activity and stability for acidic OER.

LiMnxFe1-xPO4 are considered highly promising cathode materials for next-generation lithium-ion batteries due to its high operating voltage, high energy density, excellent thermal stability, and environmental friendliness. To address the intrinsic limitations of LiMnxFe1-xPO4 cathode materials, including poor electronic conductivity and limited cycling stability, a Co and Ti co-doped LiMn0.6Fe0.4PO4 material with a gradient co-doping structure (denoted as LMFP-Co@Ti) was successfully synthesized via a two-step carbothermal reduction process. The Ti-rich outer layer effectively suppresses Mn dissolution and mitigates Jahn-Teller distortions, while the Co-doped inner layer enhances electronic conductivity and Li+ diffusion kinetics, achieving an optimized balance between electrochemical activity and structural integrity. Electrochemical evaluations demonstrate that the LMFP-Co@Ti electrode delivers an initial discharge capacity of 137.67 mAh g-1 at 1C and retains 80.5 % of its capacity after 500 cycles, markedly outperforming pristine LiMn0.6Fe0.4PO4 (LMFP) and the uniformly co-doped a uniformly co-doped sample LiMn0.6Fe0.36Co0.01Ti0.03PO4/C (LMFP-CoTi). Even under high-rate conditions (10C), the LMFP Co@Ti maintains an impressive discharge capacity of 100.94 mAh g-1, confirming its superior rate capability and long-term cycling stability. This work provides new insights into the rational design of dual-doped olivine-type cathodes, demonstrating that the gradient structure can effectively balance high-rate performance and longterm structural stability for next-generation lithium-ion batteries.

Palladium (Pd) is regarded as one of the best catalysts for alkaline oxygen reduction reaction (ORR) in anion exchange membrane fuel cells (AEMFCs). Nevertheless, oxygen adsorption on Pd is slightly strong and awaits rational modulation strategies. It is challenging to modify the adsorption of oxygen intermediates based on precise control over surface structure. Herein, using PdxW as model catalyst, the first-principles calculations reveal that a rational control of the range of oxyphilic metal W content is crucial for oxygen adsorption. Hence a series of PdxW catalysts with tunable W content are synthesized. Their ORR activities display a volcano-shaped dependence on the content of W. The Pd48W/C catalyst, with single-atomic W atoms at the near-surface confirmed by X-ray absorption spectrum, exhibits the optimal performance with a mass activity of 2.28 A/mgPd at 0.9 V (vs. RHE) in an alkaline electrolyte and membrane electrode assembly. In situ ATR-SEIRAS and density functional theory (DFT) calculations reveal that the enhanced ORR performance stems from weaker *OH adsorption and stronger *OOH adsorption, whereby the scaling relation of the oxygen intermediates is decoupled. This work demonstrates a strategy of designing high-performance Pd-based ORR catalyst with early-transition metals for AEMFC.

Limited proton conductivity within the catalyst layer induces severe ohmic polarizations and constrains power output at high hydrogen-to-electricity efficiencies in proton exchange membrane fuel cells. We demonstrate that proton transfer can be boosted by constructing Brønsted acid–Lewis base interfaces through integrating organic open frameworks with Nafion. These confined interfaces mediate low-barrier relay pathways, disrupt hydrogen bonding to expedite water network reorganization, facilitate consecutive proton transfer, and enrich protons locally. Compared with Nafion, the complexes exhibit an order-of-magnitude increase in proton self-diffusion coefficient, a 6.5-fold rise in proton conductivity, and a 55% reduction in activation energy. When integrated with commercial platinum on carbon, they deliver a fourfold increase in rated power output relative to the baseline, outperforming representative state-of-the-art membrane electrode assemblies with advanced catalysts under similar conditions.

Supported catalysts are an effective approach in proton exchange membrane water electrolysis (PEMWE) owing to their enhanced metal-support interfacial interaction. We propose a novel high-temperature shock (HTS) technique by Joule-heating to construct an electronic coupling interface between IrO2 nanoclusters catalysts and TiO2 support (IrO2 /TiO2 -HTS). The HTS strategy features an ultrafast heating rate and compresses the synthesis time from hours to seconds (2 h to 60 s). The as-prepared catalyst features uniformly embedding the ultrafine IrO2 nanoclusters enrich oxygen vacancies within the redox-active metal oxide matrix, yielding exceptional mass activity and ultrastable performance. The mass activity of the catalyst is 1081 A/gIr at 1.6 V vs. RHE, 13 times higher than of commercial IrO2 , and it demonstrates operation time for over 1100 h at 10 mA/cm2 with a voltage decay rate of only 40 & micro;V/h. This HTS strategy offers a scalable route to accelerate vacancy engineering and strong metal oxide-support interaction (SMOSI) formation, enabling high activity at reduced Ir loading and long-term stability under acidic conditions. The approach is general and can be extended to other supported binary oxides, opening opportunities for the development of additional high-performance OER catalysts and PEM-relevant electrolysis systems. (c) 2026 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Developing miniature robots with multimodal mobility in complex environments remains challenging. This study developed miniature robots based on magnetic particle-doped liquid crystal elastomers (LCEs) that integrate multicomponent functional doped materials and LCE molecular orientation engineering. Thanks to the synergistic introduction of magnetic particles with photothermal effects and 5CB plasticizer, the robot exhibits fast photothermal response in both terrestrial and underwater environments. In the terrestrial environment, the designed photomagnetic dual-field coupling strategy reshapes the physical boundaries of robots, improving their obstacle-crossing ability and achieving asymmetric full-orientation dual-mode jumping. In the underwater environment, the robot utilizes frequency laser flapping to induce wake vortex rings to overcome moderate Reynolds number drag. Especially, by utilizing the spatial resolution of the local light field, it successfully achieves efficient directional propulsion and flexible steering control by switching the irradiation position to break fluid symmetry, substantially alleviating the spatial-control limitations of globally applied magnetic fields. Finally, we demonstrated potential applications of designed miniature robots on targeted photothermal therapy of cancer cells with high accuracy. We expect that the newly developed dual-responsive and multifunctional miniature robots will find broad medical applications, such as targeted drug delivery and minimally invasive surgery.

The electronic spin state of metal atomic catalysts is pivotal in determining their catalytic activities. However, such catalysts that are prepared via conventional synthetic approaches often suffer from poorly defined coordination environments, which create challenges in precisely controlling their electronic spin configurations. Herein, we show that a CoFe dual-atom catalyst featuring coordinatively asymmetric FeN2 and CoN3 sites with a fixed coupling distance can be synthesized using a conjugated microporous polymer (designated as CoFe-CMP) and then demonstrate that the catalyst promotes the key reactions underlying both charging and discharge processes of sulfur cathodes. Experimental and theoretical data reveal that the Fe atoms adopt a high-spin state (S = 3/2) and the Co atoms assume a low-spin state (S = 1/2). The former configuration enhances electronic coupling with polysulfides, while the latter promotes the diffusion of Li atoms that are released upon Li2S degradation. Collectively, these processes facilitate the interconversion between polysulfides and Li2S, which are critical for optimizing lithium-sulfur (Li-S) battery operation. Li-S cells containing CoFe-CMP as the sulfur host exhibit outstanding performance in terms of specific capacity (1487 mAh g-1 at 0.1 C), rate capacity (676.3 mAh g-1 at 5 C), and cycling stability (a specific capacity of 499.2 mAh g-1 is measured after 300 cycles at 0.2 C). This research provides a general methodology for tuning the electronic spin states of metal atomic catalysts, as well as guidance for adapting these catalysts for use in other applications.

The performance of proton-exchange-membrane fuel cell (PEMFC) is known to be highly restrained by the nano-micro-scale ionomer-catalyst interface structure. The commonly used ionomers in the catalyst layer are functionalized by forming a nanoscale network with platinum-group-metal (PGM) based catalyst. The imbalanced binding strengths of sulfonate groups to the PGM surface compared to the carbon support surface lead to the favorable occupation of active sites for oxygen reduction reaction (ORR) and the declining performances in membrane electrode assembly (MEA). In this work, by employing a dual strategy on PGM and carbon support, a catalyst/support design is proposed to significantly reduce the variance in adsorption energies of sulfonate to the PGM and carbon surface. The balanced adsorption of sulfonate groups enables a more uniform distribution of ionomer on the catalyst surface with enhanced catalytic activity. The PtCo/CNH-N catalyst not only achieves a power density far exceeding that of its counterpart in MEA but also exhibits high stability against ionomer poisoning throughout potential cycling. Combining experimental evidence and theoretical calculation, this work corroborates the essential role of balanced binding strengths of sulfonate groups to PGM and carbon surface, and provides insight into the ionomer poisoning issue towards the design of a highly stable catalyst for PEMFC. (c) 2026 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

The activity-stability trade-off for IrO2 constrains the development of proton exchange membrane water electrolyzers (PEMWEs). Conventionally, high IrO2 crystallinity ensures oxygen evolution reaction (OER) stability while compromising activity, while amorphous structure offers high OER activity while sacrificing durability. Herein, we develop a kinetically constrained amorphization strategy using high-temperature thermal shock to precisely tune IrO2 crystallinity, capturing an ideal intermediate state: low-crystallinity IrO2 (LC-IrO2). LC-IrO2 merges the high activity of amorphous IrO2 derived from the short-range order and the robust stability of crystalline IrO2 with structural rigidity. Consequently, the LC-IrO2 catalyst simultaneously achieves excellent catalytic activity and stability for acidic OER. A PEMWE using a LC-IrO2 anode requires only 1.69 V to reach 1 A cm-2 at 60 °C and maintains steady operation for 500 h with a negligible degradation rate. This study demonstrates kinetic crystallinity control as a new paradigm for electrocatalyst design.

The replacement of Pt/C catalysts with Pt-based alloy catalysts was considered a promising strategy to reduce platinum-group-metal (PGM) content in proton exchange membrane fuel cell. However, inexpensive transition metal atoms in Pt-based alloy catalysts are subject to metal dissolution issues, leading to stability issues of oxygen reduction reaction (ORR) catalysts. In this work, a PtCuNi/C-WO3-x catalyst is designed employing non-stoichiometric WO3-x with abundant oxygen vacancies (Ovac). The WO3-x can dramatically improve the stability of PtCuNi without sacrificing the activity. Theoretical calculation suggests a decreased vacancy formation energy of W in WO3-x at the presence of Ovac, as well as increased vacancy formation energies of Pt/Cu/Ni in PtCuNi alloy particles with the existence of surface W dopant. Combined with the experimental discovery of slower dissolution rates of metals in PtCuNi/C-WO3-x catalyst, a dissolution-induced stability enhancement mechanism is proposed, whereby facilitated dissolution of W atoms from WO3-x bulk could re-deposit on Pt-alloy surface and inhibit the dissolution of catalytically active metal atoms, revealing a dynamic process that enhances the stability. The PtCuNi/C-WO3-x also shows great potential to be used as cathode catalyst in membrane electrode assembly for high-temperature proton exchange membrane fuel cells.

Conventional water electrolysis is hindered by the sluggish kinetics of the oxygen evolution reaction (OER). Here, we demonstrate that replacing OER with the thermodynamically favorable sulfur oxidation reaction (SOR) not only reduces energy consumption but also enables simultaneous S2-pollutant recovery. In this work, Wdoped Co2NiS4 (WCoNiS) nanoparticles were synthesized as an efficient SOR catalyst. The doping of W modulates the electronic distribution of Co and Ni sites, appropriately adjusts the adsorption energy of sulfur intermediates, facilitates the desorption process, thereby reducing the reaction energy barrier and enhancing the reaction kinetics. Integrated into a SOR-HER system, the WCoNiS catalyst requires only 0.885 V for 500 mA cm- 2 and remains stable for 140 h at 110 mA cm- 2. This work not only presents an innovative synthesis strategy for transition metal-based SOR catalysts but also establishes an energy-efficient pathway for co-producing hydrogen and value-added elemental sulfur.

Heavy metal ion pollution has become one of the most serious environmental problems, which promotes the continuous exploration of new materials and methods to achieve efficient detection of heavy metal ions. Luminescent metal-organic frameworks (LMOFs) featuring designable, functional structures and tunable luminescence properties exhibit excellent potential for the recognition and detection of heavy metal ions. Herein, a Cd(ii)-based luminescence MOF {[Cd2(2F-bpdc)2(tib)]}n (NKM-103) (tib = 1,3,5-tris(1-imidazolyl)benzene; 2F-H2bpdc = 3,3 '-difluorobiphenyl-4,4 '-dicarboxylic acid) was successfully designed and synthesized. Owing to the luminescence characteristic of the tib ligand with conjugated units, NKM-103 demonstrates excellent fluorescence emission performance and potential as a sensor for detecting both Fe(iii) cations and Cr(vi) anions (Cr2O72- and CrO42-) through a turn-off effect. Moreover, NKM-103 shows low detection limit and high selectivity for all three types of ions.

Perovskite solar cells (PSCs) based on metal halides have garnered significant attention due to their exceptional power conversion efficiency (PCE) and compatibility with low-temperature fabrication processes. However, the development of stable and inexpensive carbon electrodes remains hindered by issues such as insufficient conductivity at the carbon electrode/perovskite interface and weak coupling strength. In this study, we employed a functionalized carbazole-cellulose composite (C-Cz) as an alternative binder to construct highly stable carbon electrodes for PSCs. The incorporation of C-Cz enhances electron interactions through its conjugated carbazole moieties, while the cellulose backbone facilitates uniform dispersion of carbon particles and forms continuous transport pathways. These synergistic effects significantly optimize interfacial energy alignment and defect passivation. Ultimately, p-i-n PSCs fabricated with C-Cz carbon paste electrodes achieved a champion PCE of 16.79%, substantially outperforming the control device using a conventional PMMA binder (10.56%). Notably, the exceptional hydrophobicity and defect passivation capabilities of the C-Cz electrode substantially enhance device durability-maintaining over 95% of initial efficiency after 400 h of continuous maximum power point tracking irradiation. This study reveals an effective adhesive engineering strategy for robust, scalable carbon electrodes, paving new pathways for practical applications in stable perovskite photovoltaics.

Heteroatom-doped porous carbon (HDPC) materials have bloomed as a popular supporting material for metal catalysts used in oxygen reduction reaction (ORR). However, their intrinsic activity and catalytic mechanism are not well understood. Herein, hierarchically porous S, N-doped carbon flower (H-SNF) was synthesized and investigated as an ORR catalyst. Through a systematic electrochemical measurement technique, it is confirmed that H-SNF with abundant hierarchically porous structures shows improved electrochemical mass transport and favorable diffusion of O2 and OH−. The optimal H-SNF shows outstanding ORR performance with an onset potential of 0.97 ​V (vs. RHE) and half-wave potential of 0.81 ​V. The H-SNF-based zinc-air battery yields a high open circuit voltage of 1.40 ​V, peak power density of 161.4 ​mW ​cm−2. Density functional theory (DFT) calculation reveals that the pyridinic-N/graphitic-N atomic pair boosts the catalytic efficiency by optimizing the absorption/desorption of ∗OOH. The dual atomic site structure can enable a bifunctional mechanism where the pyridinic-N site acts as the “quick-start” triggering site to convert O2 to ∗OOH, with ∗OOH transfer to the adjacent graphitic-N site and is converted to ∗O immediately. This work provides a unique HDPC material towards ORR, reveals their intrinsic catalytic mechanism, and sheds light on the design of high-performance carbon materials.

As environmental concerns grow, there is a global shift from traditional fossil energy. Hydrogen fuel cells are gaining attention, but high material costs limit their adoption in large scale. The oxygen reduction reaction at the cathode of fuel cell, which dominates the electrochemical kinetics, relies mainly on platinum-group-metal (PGM) catalysts, hence research is focused on minimizing PGM or developing non-PGM catalysts. Porous materials possess unique physicochemical properties, and have shown great potential in advancing catalyst technology in fuel cells. This review summarizes the recent fundamental and technological advances of porous catalysts for oxygen reduction reactions including PGM and non-PGM catalysts, discusses the mechanisms underlying the enhanced catalytic activity through structural design and surface modification. It also highlights the comprehensive impact of porous materials in oxygen reduction reactions and membrane electrode assemblies, the main challenges, and provides perspectives on research of porous catalyst.