Most electrochemical reactions in clean energy conversion and environmental remediation rely on coupled electron–ion transport, yet their rate- and selectivity-determining steps often occur at the electronic and spin levels. Such processes are difficult to directly capture and validate using conventional structural or valence-state characterizations. Consequently, electron paramagnetic resonance (EPR) offers a unique mechanistic advantage in probing electrochemical reactions by sensitively detecting unpaired electrons, tracking radical intermediates, and revealing spin-dependent electron localization/delocalization. This article reviews recent advances in EPR for electrocatalysis, highlighting its capabilities in tracking transition-metal valence evolution and probing oxygen reaction pathways and radical intermediates. It further extends the scope to another important area of electrochemical science, electrochemical energy storage, where EPR has been widely applied to elucidate key processes such as anionic oxygen redox mechanisms. By correlating specific paramagnetic signatures, including transient intermediates and reactive oxygen species, with macroscopic kinetic behavior, EPR provides critical supporting evidence for elucidating mechanisms and informing the rational design of electrocatalysts. Finally, the article discusses current challenges and future advances in high-field, multi-frequency, operando, and multimodal EPR, emphasizing how spin-resolved mechanistic insights can be translated into catalytic descriptors for active-site regulation, pathway optimization, and performance evaluation.

The simultaneous achievement of efficient NOx reduction and N2O byproduct suppression during NH3-SCR represents a core challenge in engine exhaust aftertreatment. This study prepared Co-Fe-Beta zeolite via an impregnation method. Combining characterization, catalytic evaluation and density functional theory (DFT) calculations, we systematically investigated the catalyst’s microstructure, catalytic performance and reaction mechanism. Characterization results demonstrate that no large metal oxide particles or agglomeration are observed in the Co-Fe-Beta zeolite catalysts. Co and Fe atoms are uniformly dispersed within the nanopores of the Beta zeolite framework, while the characteristic crystalline phase, nanoporous structure of the Beta zeolite are well preserved. Catalytic evaluation indicates that 2 %-2 %–Co-Fe-Beta exhibits optimal performance in a 100-400 °C venting atmosphere, demonstrating significantly enhanced N2 selectivity compared to single-component Fe-Beta and substantially reduced N2O by-product formation. DFT calculations reveal that the Fast-SCR main reaction follows the Eley-Rideal (E-R) mechanism, with the pathway ‘dual NH3 adsorption → NO activation to form N2H intermediate → NO2 participation in reaction’ (Path1) being the dominant route, exhibiting a rate-determining step energy barrier of merely 0.50 eV. The synergistic effect between Co and Fe not only affords excellent NOx reduction performance in NH3-SCR but also achieves effective suppression of N2O byproduct formation. This study confirms the crucial role of the synergistic effect between Co and Fe bimetallic sites in boosting NH3-SCR catalytic activity and N2 selectivity while suppressing N2O byproduct formation. It provides experimental evidence and theoretical guidance for the development of high-performance exhaust aftertreatment catalysts.

The rational design of low-cost, efficient, and corrosion-resistant electrocatalysts is crucial for hydrogen production via direct seawater electrolysis. Herein, a dual modulation strategy targeting composition and valence states is developed by synthesizing an ultrasmall RuRe alloy catalyst. Comprehensive characterization reveals that incorporating inexpensive Re as a secondary component facilitates the formation of ultrasmall alloys with tunable compositions. Moreover, the enhanced oxophilicity induced by the size effect promotes the spontaneous partial oxidation of the alloy surface. Density functional theory (DFT) calculations confirm that the introduction of Re accelerates the Volmer step, while the generated surface oxidation states not only promote the Tafel step but also suppress Cl- adsorption, thereby enhancing both catalytic activity and long-term stability in seawater splitting. As a result, the ultrasmall RuRe alloy exhibits superior HER kinetics, achieving low Tafel slopes of 32.25 mV dec-1 in 1.0 M KOH, 42.68 mV dec-1 in alkaline seawater, and 163.17 mV dec-1 in real seawater, along with a stable operation exceeding 180 h. Furthermore, an on-site photovoltaic-driven direct seawater electrolysis system was constructed, confirming the practical feasibility of the ultrasmall RuRe catalyst. This study provides an effective strategy for designing highly efficient and durable electrocatalysts for hydrogen production.

SnSe, known for its narrow bandgap and visible light absorption capability, serves as a photocatalyst for environmental remediation. This work employs strain and band modulation to enhance photocatalytic performance through WO3/SnSe micro-nano composite construction. Strain energy density (SED) calculations using the Williamson-Hall method reveal substantial lattice strain in the 2.5% WO3/SnSe composite, reaching 83.6 J cm-3. Combined experimental characterization and density functional theory (DFT) calculations demonstrate that strain modulation improves methyl orange (MO) adsorption energy, extends visible light absorption, and facilitates electron transfer and charge carrier separation. The optimized 2.5% WO3/SnSe composite achieves 99.71% MO degradation within 60 min, representing an 11.7-fold enhancement in reaction kinetics compared to pristine SnSe. The heterostructure induces favorable band alignment that promotes the formation of and & centerdot;OH active species. These findings establish strain and band modulation as viable strategies for developing high-performance photocatalysts.

Precise stereochemical control in heterogeneous catalysts remains fundamentally constrained because catalytic sites typically emerge only after framework assembly, intrinsically coupling their spatial definition to pore architecture. This limitation is particularly severe in mesoporous metal-organic frame-works, where enlarged pores enhance accessibility but weaken stereochemical discrimination. Here, we report a reticular design strategy in which the complete catalytic site architecture is molecularly encoded within a building unit prior to framework formation. A bifunctional BINOL-derived phosphate-carboxylate ligand integrates Lewis acid functionality and a spatially defined chiral environment in a fixed geometric relationship. Assembly with Zn2+ generates a mesoporous chiral framework with ∼23 Å channels while preserving structurally locked Zn-phosphate catalytic sites embedded within preorganized chiral pockets, as confirmed by single-crystal analysis. Catalytic and control studies suggest a direct correlation between encoded site geometry and enantioselectivity, demonstrating a general strategy for programming catalytic function in crystalline porous materials.

Abstract Solid-state hydrogen storage by gas hydrates offers a novel pathway for large-scale, static, and mild storage. However, its application is hindered by inherently low storage and sluggish formation rate. In this work, nanohydrogels were synthesized and systematically evaluated for their performance, recyclability, and kinetic promotion effect on H2/DIOX binary hydrates. The results demonstrate that both particle size and concentration of nanohydrogels significantly influence their promoting performance. In particular, nanohydrogel N3 at a concentration of 0.3 wt % exhibited the best performance, achieving a hydrogen storage capacity of 0.517 wt %, representing a 127.7% increase compared to the pure 1,3-dioxolane (DIOX) system. The hydrate growth rate was also enhanced by 106.3%, marking a substantial improvement in efficiency over traditional systems. In addition, the promotion effect remained stable over 10 cycles, indicating excellent durability and reusability. Raman spectroscopy indicates that the hydrate formed is of structure II, and its crystal structure is not affected by the nanohydrogels. In situ μ-DSC disclosed the intricate effects of nanohydrogels on crystallization and demonstrated the condition-dependent nature of their promotion performance. Moreover, distinct from traditional approaches that focus on altering hydrate structures, this novel hydrogel promotes hydrate-based hydrogen storage by a dual mechanism of interfacial regulation and enhanced hydrogen transport, offering a new understanding and technological pathway for efficient hydrate-based hydrogen storage. This study not only overcomes the efficiency bottleneck in hydrogen storage by hydrate but also contributes significantly to its widespread commercial applications by robust stability and economic viability.

The electrochemical CO2 reduction reaction (CO2RR) to multicarbon products is constrained by the challenge of directing selectivity toward ethanol over ethylene. Herein, Ag was loaded onto a 2D Cu-MOF to reconstruct the local microenvironment of its symmetric dual-Cu sites. The resulting Ag@Cu(4-pt) shifts C2 selectivity from ethylene-dominant to co-production of ethylene and ethanol, delivering a peak ethanol Faradaic efficiency (FE) of 6.90% at -1.3 V vs. RHE. Theoretical calculations indicate that interfacial electron transfer induces an asymmetric Cu microenvironment, enriches *CO intermediates, and increases the likelihood of oxygenated C2 pathways. This work provides a rational loading strategy to manipulate CO2RR pathways for selective CO2-to-C2H5OH conversion.

Non-radical pathways have attracted increasing attention in diverse heterogeneous advanced oxidation processes (HAOPs) employing metal-organic framework (MOF)-based functional materials owing to their advantages including excellent pollutant degradation performance, ultra-high selectivity, low oxidant consumption, strong anti-interference capability, and broad pH applicability. However, the complexity of the various formation and conversion pathways, along with the available identification methods, has led to an unclear understanding of the non-radical formation mechanisms mediated by MOF-based catalysts. This work systematically summarizes the characteristics, formation pathways, and identification methods of different non-radical pathways across various AOP systems involving singlet oxygen (1O2), high-valent metal-oxo species (HVMOs), electron transfer process (ETP), direct oxidative transfer process (DOTP), and surface-bound radicals. Furthermore, recent advances in MOF-based catalysts for the catalytic degradation of organic pollutants are presented, with an emphasis on the relationship between the structure of MOF-based catalysts and the corresponding non-radical generation mechanisms. Finally, current drawbacks and future outlooks regarding non-radical pathways in MOF-based catalysts for water purification are discussed. This review aims to provide valuable insights to advance the development of organic pollutant elimination using MOF-based functional materials.

The synthesis of high-nuclearity titanium metal-organic polyhedra (Ti-MOPs) has remained a formidable challenge due to the high oxophilicity and hydrolysis susceptibility of Ti4+ ions. Herein, we report a Ti24 MOP with a truncated octahedron (tro) topology, which represents the highest nuclearity Ti-MOP reported to date. Beyond structural characterization, we introduce a pathway intervention strategy using Ni2+ as a kinetic modulator to trap and structurally characterize two key intermediates-a Ti12 macrocycle and a Ti12 (6-4-6) module. These intermediates outline a hierarchical assembly pathway from simple precursors to Ti24 MOP. Furthermore, we demonstrate that this process is governed by a coordination lability gradient between Ti4+ and Ni2+, providing an effective strategy for directing supramolecular complexity. This Ti-MOP exhibits permanent microporosity, gas separation, and post-assembly modification capability. This work transforms a synthetic challenge into a strategic advantage, offering a blueprint for the rational assembly of complex metal-organic architectures.

Supercapacitors (SCs) are emerging as the new-generation energy storage device because of their high-power density, quick charge-discharge rate, and long cycle life, which can be critical to the sustainable and efficient energy system. A high-performance asymmetric supercapacitor (ASC) with a CdO-CuO nanocomposite and activated carbon configuration was developed in this study. The combination of CdO and CuO in the hybrid material provides the electrochemical characteristics of the two components, which results in improved electrical conductivity, redox-active sites, and really efficient ion diffusion channels. Hence, the CdO-CuO electrode was continuous charge-discharge cycles at a current density of 9 A.g- 1, it sustained 88.7% of its initial capacitance, thereby indicating excellent reversibility and long-term stability. The CdO-CuO//AC device assembled a high energy density of 41.6 Wh.kg- 1 at a power density of 11076 W.kg- 1 and remained stable over an extended potential window of 1.6 V using an aqueous electrolyte. Overall, the findings demonstrate that the CdO-CuO nanocomposite is a highly promising electrode candidate, contributing to the advancement of highperformance supercapacitors for future sustainable energy systems.

Oxygen-enriched CO oxidation is a pivotal reaction in automotive exhaust and indoor air purification. Fine-tuning the active sites represents a significant challenge in this catalytic field. In this work, we modulated the chemical state of Pt on Pt/CeO2 catalysts by varying pretreatment atmospheres (direct H2 reduction and sequential O2 calcination-H2 reduction), then applied these catalysts to the CO oxidation reaction. It was found that the Pt/CeO2 catalyst via direct H2 reduction showed a much higher activity than the Pt/CeO2 catalyst via sequential O2 calcination-H2 reduction. It was revealed that under O2-H2 conditions, a strong metal-support interaction (MSI) introduced the highly dispersed small Pt clusters. Conversely, under H2 reduction conditions, a moderate MSI causes the formation of larger Pt nanoparticles, exhibiting a significantly increased proportion of metallic states and promoting the activity of CO oxidation. This study provides an effective strategy for designing highly efficient catalysts.

Porous liquids, as a novel class of functional materials that combine the permanent porosity of solids with the fluidity of liquids, overcome the limitations of conventional porous solids, such as poor processability and low mass transfer efficiency, as well as the lack of specific recognition capabilities in traditional liquids, thereby providing innovative solutions to technical bottlenecks across multiple fields. This paper systematically reviews the research progress on porous liquids, with a focus on the synthesis strategies for Type I-IV porous liquids, including key methods such as surface engineering, electrostatic interactions, supramolecular complexation, and like-dissolves-like approaches. It further explores their core applications in gas capture and separation (CO2, hydrocarbon gases, SO2, VOCs) and catalytic conversion (CO2 conversion, various types of organic catalytic reactions), while also summarizing their exploratory applications in emerging fields such as membrane separation, chiral recognition and separation, biomedicine, heavy metal ion extraction, and sensing. Finally, the review analyzes the major challenges porous liquids currently faces, including the lack of systematic guidance for design and synthesis, high costs, difficulty in balancing viscosity with solid content, and insufficient characterization techniques. Positively, it also provides perspectives on future developments in terms of low-cost scalable preparation, expansion of application domains, and innovation in multiscale characterization methods, provides a reference for the exploration of porous liquids from laboratory research toward industrial applications.

Optical anisotropy and phase-matching capability are critical requirements for high-performance nonlinear optical (NLO) crystals, yet they are inherently difficult to achieve simultaneously. Chiral metal-organic frameworks (CMOFs), with tunable coordination environments and crystal symmetry, provide a promising platform for addressing this challenge. Herein, a coordination geometry-directed strategy is proposed to regulate optical anisotropy and phase-matched nonlinear optical behavior in CMOFs. By employing the same chiral ligand while varying the metal centers (Zn2+ versus Cd2+), two CMOFs featuring tetrahedral and octahedral coordination geometries were constructed, leading to distinct crystal symmetries and lattice anisotropies. Structural analysis reveals that the octahedrally coordinated Cd-based framework exhibits symmetry lowering and pronounced unit-cell anisotropy, resulting in a markedly enhanced birefringence (Δn = 0.113 experimentally and 0.198 theoretically at 546 nm), nearly three times that of its Zn analogue. As a consequence, effective phase-matchable second-harmonic generation is achieved, with an SHG efficiency comparable to that of KDP. Density functional theory calculations further demonstrate that the distorted octahedral coordination geometry and coordination-enhanced charge redistribution give rise to strong electronic anisotropy, polarizability anisotropy, and hyperpolarizability. This work establishes coordination geometry as a decisive structural parameter for directing optical anisotropy and nonlinear optical performance in CMOFs.

CeO 2 is a promising photothermal catalytic candidate in the field of CO 2 resource conversion. However, its further application is limited by insufficient visible light absorption and photogenerated carrier recombination. This study prepared a Au–CeO 2 photothermal catalyst with high performance via low-temperature in situ reduction. Through the synergistic effect of the Au–O–Ce interface and photothermal action, the prepared Au–CeO 2 achieved a CO production rate of 2,971.3 μmol/g within 3 h (147 times higher than pure CeO 2 ), with 99.9% CO selectivity and no obvious activity degradation over 12-h continuous operation. The in situ characterization and density functional theory calculations showed that localized surface plasmon resonance effect of Au nanoparticles efficiently captures visible light into local thermal energy and high-energy hot electrons. Heat energy not only provides additional kinetic energy for the reaction, reducing the activation energy barrier of the reaction’s rate-limiting step, but also drives the desorption of the product CO. The Au–O–Ce interface acts as an electron transfer bridge, promoting hot electron injection into the conduction band of CeO 2 to substantially reduce the *CO 2 →*COOH activation barrier and inhibit carrier recombination. This work provides expandable interface engineering insights for designing efficient, stable, low-cost photothermal catalysts with high CO selectivity.

Engineering geometric asymmetry in molecular architectures offers a powerful strategy for boosting third-order nonlinear optical (NLO) responses, yet such approaches have not been reported for metal-oxo clusters. Here, we synthesized three iron-oxo clusters [Fe7(μ4-O)4(FcDCA)6] (Fe7OC), [Fe6Ca(μ4-O)4(FcDCA)6] (Fe6CaOC), and [Fe6Na(μ3-O)4(FcDCA)6] (Fe6NaOC) (ferrocene dicarboxylic acid = H2FcDCA) with spatially distorted cluster cores via a heterometal incorporation strategy. Single-crystal X-ray diffraction analysis reveals incorporation of heterometal Ca or Na ions induces severe tetrahedral-core distortion through bond elongation, leading to breaking spatial symmetry in the geometric structure of the cluster core. Spectroscopy and Z-scan measurements demonstrated that the symmetry breaking of these geometric structures in the Fe-oxo clusters results in a narrowed optical band gap and a substantially increased third-order nonlinear absorption coefficient (β). Theoretical calculations indicate that the introduction of heterometals lowered the band gap of Fe-oxo clusters, enhanced the nonlinear hyperpolarizability, and improved the third-order NLO performance. Furthermore, the metal-oxo cluster-based polymer liquid crystal device prepared by mixing Fe6NaOC clusters with nematic liquid crystals not only has high transmittance and electro-optical switch characteristics, but also has stronger optical limiting performance. This work not only develops new high-performance NLO metal-oxo cluster materials with geometric symmetry engineering, but also establishes metal-oxo cluster-based electro-optical smart devices for nonlinear optical limiting applications.

In this study, F/Cu/VZn/Hi multi-defect coupled ZnS systems were innovatively constructed, and the regulatory mechanisms of their structure, magnetism, conductivity type, and photocatalytic CO2 reduction performance were systematically investigated. Structural stability of the systems is significantly enhanced by the synergistic introduction of F/Cu/Hi (formation energy as low as − 4.376 eV). Magnetism of the systems originates from unpaired spin electrons in the Cu2-3d9 orbital, with a magnetic moment contribution of 1 μB. A regular transition of magnetic moment spin distribution from localized states (Cu2+-S2−) to delocalized states (Zn-4s) is observed with increasing F− concentration. Different conductivity types can be achieved via precise regulation of F− concentration (n-type at 4.23 D̅ = 3.54). Its conduction band minimum energy level is precisely matched with the potential for CO2 reduction to CH4, and CO2 adsorption/activation efficiency is significantly enhanced by the short-range synergistic effect between VZn and F−. ZnS-based functional materials with tunable magnetism, controllable conductivity type, and high-efficiency photocatalytic performance are successfully constructed, providing new insights and experimental support for the design of high-performance materials for spintronic devices and photocatalytic CO2 reduction cells.

Core-shell structured materials exhibit superior stability and catalytic performance in catalytic applications. The unique microenvironment of the core-shell catalyst facilitates efficient enrichment and adsorption of low-concentration, high-mobility atmospheric pollutants. Furthermore, these catalysts have found widespread application in the control of atmospheric contaminants attributed to the synergistic interplay between core-shell components and the protective barrier function of the shell architecture. This paper comprehensively reviews the preparation method of core-shell catalysts and their application in the control of air pollutants. This paper focuses on the advantages of core-shell catalysts and the main types of core-shell catalysts employed in deNOx processes. Recognition of the relationship between the structural composition of core-shell catalysts and their catalytic performance, as well as exploring the synergistic effects, heat and mass transfer, and underlying catalytic mechanism. This review offers critical guidance for the design and development of application-oriented core-shell catalysts to abate atmospheric pollutants.

Developing high-quality wide-bandgap (WBG) perovskites is crucial to construct efficient perovskite/silicon tandem solar cells (TSCs). However, the high defect density and halide segregation hinders the improvement of power conversion efficiency (PCE) and stability for WBG perovskite solar cells (PSCs). Herein, one carboxyl-functionalized imidazolium cation modulation strategy is reported to heal the multiple defects within WBG perovskite films by multifarious chemical bonding modes. After incorporating the additive imidazole-4-acetic acid hydrochloride (ImAcHCl), the trap-assisted nonradiative recombination at grain boundaries is suppressed, the halide segregation is mitigated, and the stability of perovskite films is improved. Moreover, this method is effective in defect passivation for different bandgaps of perovskites. Ultimately, the ImAcHCl-modified 1.68 eV WBG PSCs achieve a PCE of 24.54% ranking among the highest PCEs realized for 1.66-1.70 eV PSCs, and retain 90% of their initial PCE after 883 h of continuous maximum power point tracking. Integration with crystalline silicon subcells further enabled the construction of a perovskite/Si tandem device with a PCE of 33.06%. This work provides valuable insights into overcoming the instability challenges of the WBG perovskite film via functional group functionalization method toward high-performance WBG PSCs and perovskite/silicon TSCs.

Coal-series kaolin (CSK), a large-scale solid waste, has caused significant environmental pollution. Its effective conversion into high-value products remains a challenge. In this study, mullite-based ceramics featuring needle-like microstructures were controllably prepared by adding Ta2O5 without the need for additional sintering acids. The resulting ceramics exhibited superior wear resistance. Ta2O5 reacts with Al2O3 to form Ta-O-Al chemical bridges. Combined with density functional theory (DFT) calculations and experimental data, these chemical bridges effectively lower the nucleation energy barrier for new crystalline phases and provide anchoring sites. This drives the transition from equiaxed grains to interwoven whiskers and facilitates the preferential one-dimensional anisotropic growth of the mullite phase. Due to the distinctive needle-like mullite microstructures and the pinning effect of AlTaO4, the wear rate decreases by 89% compared to the blank sample. These results demonstrate that Ta2O5 regulates the crystal growth and friction behavior of mullite, offering an economically effective strategy for utilizing CSK.