Carbon dioxide (CO₂) capture and hydrogenation reduction (CCR) offers a promising route to reduce greenhouse gas emissions while converting CO₂ into value-added chemicals, contributing to carbon-neutral strategies. Dual functional materials (DFMs), which could simultaneously achieve CO₂ capture and in-situ hydrogenation conversion in a single material system, have therefore attracted growing attention. Nevertheless, the complex reaction pathways, multiple intermediates, and parallel networks involved in CO₂ hydrogenation led to highly diverse and intricate catalytic mechanisms over DFMs. This review summarizes recent advances in DFMs for CCR, focusing on key hydrogenation pathways to CO, CH₄, and CH₃OH and the evolution of associated intermediates. Advanced in-situ/operando characterization techniques and density functional theory calculations are highlighted for their roles in elucidating reaction mechanisms and metal-adsorbent synergistic effects. DFMs are further classified by active metal type, with representative Ni-, Ru-, Cu-, and Fe-based systems critically reviewed to highlight synergistic interactions among active metals, adsorbents, promoters, and supports, as well as rational structural design strategies for mitigating sintering and deactivation. Overall, this review provides mechanistic insights and design principles to guide the development of efficient, low-energy, and industrially viable DFMs for CCR reactions.

Nitrogen oxides (NO_x) emitted from industrial processes pose severe environmental threats, necessitating efficient abatement technologies. Selective catalytic reduction with NH₃ (NH₃-SCR) at low temperatures represents a promising route, with Mn-based oxides being among the most active candidates. However, their practical application is hindered by insufficient N₂ selectivity, susceptibility to SO₂ and H₂O poisoning, and a narrow operational window. Rare earth (RE) modification has emerged as a highly effective strategy for optimizing Mn-based catalysts in low-temperature NH₃-SCR of NO_x, yet a systematic understanding of the structure-activity relationships and reaction mechanisms remains lacking. This review provides a systematic and mechanistic overview of recent advances in RE-modified Mn-based catalysts for low-temperature NH₃-SCR. We first establish the structural-performance relationships of pure MnO_x, focusing on valence states, crystal phases, morphologies, and synthesis methods. Subsequently, we classify and discuss three major catalyst families: RE-modified MnO_x, RE-Mn composite oxides, and supported RE-Mn systems. Special emphasis is placed on the roles of RE elements in enhancing low-temperature activity, broadening the temperature window, improving N₂ selectivity, and constructing multi-level anti-poisoning mechanisms against H₂O and SO₂. We further elucidate the underlying reaction pathways and how RE doping modulates the electronic structure, active site distribution, and intermediate transformation. Finally, we identify key challenges for industrial deployment, such as long-term stability under complex flue gas, scalability, and cost-effectiveness, and propose future research directions toward the rational design of robust, high-performance SCR catalysts. This work provides a mechanistic framework and design principles for developing high-performance RE-Mn catalysts under practical flue-gas conditions.

Amidst tightening mobile-source emission regulations, ammonia selective catalytic reduction remains the dominant post-treatment technology for NO_x removal, with copper-exchanged zeolites (Cu-zeolites) serving as benchmark catalysts. Here, we systematically survey zeolite topologies—such as MFI, CHA, AEI, and LTA—evaluating their catalytic performance, reaction mechanisms, hydrothermal stability, and resistance to poisoning. A comprehensive overall pathway of sequential two-NO activation on dual ZCuOH sites is unified and complements the established L-NH₃ (NH₃ bond to solvated Cu²⁺ ions) activation model in the Reduction Half-Cycle. This work provides fundamental insights into the performance, hydrothermal stability, and SO₂ resistance of Cu-based zeolites. Therefore, the fundamentals and new mechanistic insights of hydrothermal aging are summarized over Cu-SSZ-13, while highlighting Cu-SSZ-39 as an intrinsically robust successor. We dissect the SO₂ poisoning mechanisms of Cu-CHA, demonstrating that engineering the atomic-scale distribution of Cu enhances both sulfur tolerance and hydrothermal stability. Supplementary strategies (e.g., constructing protective/sacrificial sites, co-crystallization, and core-shell structures) are also considered beneficial. Beyond durability, we also focus on the two-dimensional PST-9 zeolite and OFF/ERI intergrowths zeolite for the future challenge of diffusion. Finally, we outline future research frontiers, aiming to unify Cu-zeolite theory into a mechanistic framework that translates fundamental insights into rational design principles for next-generation catalysts.

Bimetallic and polymetallic catalysis play the significant roles in versatile biological and chemical oxidation processes, however, their synergistic mechanisms, typically for these biological and heterogeneous oxidations, mostly remain vague due to the complexity of biological system and heterogeneous catalysis. Fundamentally, biological, heterogeneous and homogeneous catalysis obey the same chemical principles; accordingly, these vague synergistic mechanisms may be elucidated with homogeneous models. Indeed, since last 1990s, it has attracted much attention to investigate how the second metal ions functioning as Lewis acid (LA) to modulate the oxidative reactivity of the metal active oxygen moieties with synthetic models, and LA-modulated catalysis by redox catalysts has also been explored as well in homogeneous oxidations. This review summarizes the state of art in this field, and we hope these knowledges could help the understandings of bimetallic and polymetallic catalysis happening in both biological and chemical oxidations, thus benefit related catalyst designs for a better life.

Copper chalcogenides with rich copper vacancies in their framework have garnered increased attention in the field of photocatalysis. Engineering copper vacancies can significantly tune the optical, electronic and catalytic properties of copper chalcogenides through the introduction of defect states, orbital hybridization, and activation of surface reactants. These contribute to the wide light response from the visible to near-infrared region, enhanced charge separation, and a reduced surface catalytic barrier. In this review, copper sulfides are discussed as the primary focus, while copper selenides and copper tellurides are also included as related systems. The morphological control, chemical composition, and defect state of copper chalcogenides can be further regulated with advanced synthesis methods at the electronic and atomic scale to effectively tune the vacancies and rationally design interface assembly. The development of copper chalcogenides is broadening their applications, including solar hydrogen generation, carbon dioxide reduction, decomposition of toxic chemicals, and other light-driven reactions. However, it remains challenging to achieve atomic-level tailoring while stabilizing vacancies under operational conditions, as well as to attain long-term aqueous stability and resistance to oxidation. This review summarizes recent progress in copper chalcogenide photocatalysts and provides perspectives on the future development of defect-tolerant and full-spectrum photocatalysts for sustainable energy conversion and environmental purification.

Transitioning covalent organic frameworks (COFs) from laboratory-scale photocatalysts to practical technologies requires overcoming two fundamental bottlenecks: rapid charge recombination at the microscopic level and mass transfer limitations coupled with the engineering challenges of particulate suspensions at the macroscopic level. This review presents a multiscale engineering strategy to bridge this gap, progressing from heterojunction design to membrane fabrication. We first provide a systematic assessment of COF-based heterostructures, incorporating metals, metal oxides, and inorganic semiconductors, to elucidate the structure-activity relationships governing excitonic dynamics. Special emphasis is placed on S-scheme COF-based heterojunctions, highlighting their superior capability in facilitating interfacial charge transfer while preserving high redox potentials. Subsequently, the focus shifts to the engineering of COF membranes via techniques such as interfacial polymerization and in-situ growth, emphasizing their structural merits in macroscopic processability. Critically, we propose the integration of heterojunction concepts into membrane architectures as a pivotal strategy to resolve the inherent trade-offs between the aggregation of powder catalysts and the limited semiconductor properties of traditional polymer membranes. By analyzing recent advances in heterostructured COF membranes, we highlight how this synergistic approach simultaneously enhances charge separation efficiency, substrate flux, and operational stability. We further discuss the application of these heterojunction and membrane systems in key photocatalytic processes, including H₂ production, CO₂ reduction, H₂O₂ production, and pollutant degradation. The review concludes by outlining a roadmap for overcoming scalability hurdles, offering a blueprint for the development of efficient, robust, and industrially relevant COF photocatalytic systems.

Electrochemical synthesis offers a sustainable platform for redox transformations. However, many existing methods suffer from low Faradaic efficiency and high energy input. Herein, we report an efficient electrosynthetic strategy for the direct conversion of styrenes into tetrahydrofurans (THFs) using water as the sole oxygen source. By integrating experimental studies and theoretical calculations, we revealed that inexpensive carbon-based electrodes effectively promoted styrene activation and facilitated a radical-radical coupling of styrene-derived radical cations and hydroxyl radicals(•OH) generated in-situ from water oxidation. Moreover, key reactive intermediates were identified to support the proposed mechanism. This work established an efficient route to THFs and underscored the potential of electrochemical approaches for harnessing water as oxygen source in selective organic transformations.

Towards large-scale hydrogen production via water splitting, it is crucial to enhance the mechanical stability of electrocatalysts while maximizing the formation and utilization of efficient active sites through rational morphological design and electronic modulation. Here, a hierarchical nitride/phosphide heterostructure electrocatalyst is successfully constructed, consisting of amorphous 2D NiCoP nanosheets vertically grown on crystalline 1D NiMoN nanorod arrays. This unique structure facilitates the formation and exposure of efficient active sites while endowing NiMoN/NiCoP catalyst with a highly hydrophilic and superaerophobic surface. Accordingly, it exhibits an ultralow overpotential of 126 mV at 1000 mA cm^-2 for the hydrogen evolution reaction (HER) in 1 mol L^-1 KOH. Notably, as a bifunctional catalyst, it requires merely 1.74 V in 1 mol L^-1 KOH solution and 1.77 V in an anion exchange membrane water electrolyzer (AEMWE) to achieve 1000 mA cm^-2 of current density, while maintaining stable electrolysis for up to 1600 and 300 h, respectively. Theoretical calculations indicate the interaction between NiMoN and NiCoP leads to the redistribution of charge density. This promotes H₂O adsorption and dissociation, also optimizes the adsorption of H^* intermediates at the heterointerfacial Ni sites, consequently improving the HER activity. These characteristics highlight its promising applicability as an Ampere-level catalyst for hydrogen production.

Interfacial free water plays a vital role in accelerating electrocatalytic water splitting. However, the low proportion of free water at the interface significantly limits the reaction rate. Herein, we demonstrate a new strategy to increase the interfacial free water supply by doping single lanthanide atoms into Co₃O₄ for acidic oxygen evolution (OER). Taking La as an example, the doped La at the surface of Co₃O₄ spontaneously captures water molecules from the electrolyte through hydration, providing a sufficient free water supply for the OER. In addition, La doping strengthens Co-O bonding, affording strong structural stability. As a result, La-doped Co₃O₄ has a small overpotential of 288 mV at a current density of 10 mA cm^-2 and can remain stable for 230 h. Except for La, other lanthanide elements, such as Sm and Pr, also have similar effects on the OER. Our work not only develops efficient electrocatalysts for the acidic OER but also provides a universal strategy to increase the interfacial free water supply.

Urea-assisted electrolytic water splitting for hydrogen production represents an effective contemporary strategy for generating green hydrogen. The sluggish kinetics of the anodic urea oxidation reaction (UOR) and cathodic hydrogen evolution reaction (HER) limit their practical application. The MXene quantum dots (MQDs) promote pronounced d-d orbital hybridization between Ni and Mo sites. The constructed heterostructures facilitate electron transfer and modulate charge redistribution. The extensive formation of heterostructures between numerous quantum dots and nickel molybdate results in the emergence of flower-like clusters at the tips of rod-like NiMoO₄ particles. The augmentation of the specific surface area results in the exposure of a larger quantity of active sites, which facilitates the redistribution of charge across these active sites, consequently enhancing the hydrolytic activity. The electrocatalyst exhibits remarkable performance in both the UOR and HER, achieving 1.31 V and 55 mV at 10 mA cm^-2, respectively. The catalyst for urea-assisted water electrolysis requires only 1.38 V at 10 mA cm^-2. The prepared catalyst can be employed for seawater splitting and photovoltaic-driven hydrogen production. In-situ Raman spectrum confirms that Ni sites on the NiMoO₄/MQDs surface transform into Ni-OOH under hydrolysis and subsequently govern the hydrolytic reaction. This work indicates that d-d orbital hybridization can provide pathways for electronic transitions, thereby enhancing charge-transfer efficiency and effectively lowering reaction energy barriers.

To overcome the limitations of Pt/C catalysts in water and seawater electrolysis for hydrogen production, a anion vacancy-engineered bimetallic sulfide electrocatalyst was synthesized on a three-dimensional carbon foam support (V_S-Ni_0.55Fe_0.45S₂@CF) for highly efficient hydrogen evolution reaction (HER) under alkaline and seawater conditions. The catalyst utilizes melamine foam as a template, combining graphene oxide coating with hydrothermal carbonization to construct a three-dimensional porous carbon framework. Subsequently, the Ni_0.55Fe_0.45S₂ catalyst is in-situ synthesized via hydrothermal methods, and sulfur vacancies are introduced through ammonium fluoride (NH₄F) etching. Characterization revealed that the catalyst retained its three-dimensional porous structure, exhibiting outstanding superhydrophilicity and aerophobicity, significantly enhancing electrolyte mass transfer efficiency. Mechanistic analysis indicates that the high conductivity of carbon substrate effectively reduces electrode-catalyst interfacial resistance, while its porous structure physically blocks Cl^- migration to active sites to suppress corrosion. Sulfur vacancies modulate the surface electronic states, optimize the H* adsorption energy barrier, and induce SO₄^2- formation. This further inhibits Cl^- corrosion through electrostatic repulsion, synergistically enhancing catalytic activity and stability. Consequently, in 1.0 mol L^-1 KOH, this catalyst exhibits an overpotential of only 51 mV at a current density of 10 mA cm^-2 and demonstrates long-term durability (operating stably for 250 h). In simulated seawater (1.0 mol L^-1 KOH + 0.5 mol L^-1 NaCl), the overpotential is 77 mV with a current retention rate exceeding 70% after long-term operation. This study provides experimental support for developing low-cost, highly efficient HER catalysts and provide a basis for large-scale green hydrogen production.

The design of efficient and pH-universal ruthenium (Ru) single-atom catalysts (SACs) remains a pivotal challenge for hydrogen economy systems. Here, inspired by tubular capillary phenomena, a novel approach is introduced—autogenous force-mediated assembly—enabled by a unique asymmetric N-doped carbon nanotubes (NCNTs) scaffold with a Co-embedded sealed end. The confined geometry drives a spontaneous, directional outward migration of Co²⁺ species at room temperature, which deposit as amorphous or poorly crystalline cobalt-based compounds at the outer surface while concurrently capturing and stabilizing Ru species in single-atom configurations. And these precursors transform into well-crystallized Co₃O₄ anchored with Ru single-atom upon calcination. This process yields a precisely organized three-dimensional architecture where metallic Co nanoparticles remain confined within the NCNTs, while atomically dispersed Ru sites are firmly anchored on the exterior Co₃O₄ lattice. The gradual migration-deposition process is inherently self-limiting, ensuring uniform dispersion of Ru single-atoms (SAs). The resulting lattice confinement induces a strong electronic metal-support interaction (EMSI), which effectively suppresses atomic aggregation and optimizes the electronic structure of the active sites. The integrated system—coupling the conductive Co@NCNT with the EMSI-enhanced Ru-Co₃O₄ interface—delivers outstanding hydrogen evolution reaction performance. This work establishes a generalizable synthesis paradigm that leverages internally generated forces for the precise spatial organization of active components, presenting a versatile route toward high-performance SACs for sustainable energy conversion.

Efficient oxygen-evolving electrodes that can operate under high-current-density alkaline water/seawater electrolysis are essential for practical hydrogen production, yet the simultaneous achievement of high activity, chloride tolerance, and long-term durability remains difficult for non-precious-metal catalysts. In this work, a binder-free high-entropy layered double hydroxide electrode has been successfully constructed by directly growing multimetal LDH nanosheets on nickel foam through a facile one-step hydrothermal process. The optimized quinary LDH, composed of five non-noble transition metals, namely Fe, Ni, Co, Zn, and Cr, is denoted as CoNiFeZnCr LDH@NF. Benefiting from the high-entropy multimetal coordination environment, this electrode exhibits superior OER performance compared with the corresponding binary, ternary, and quaternary LDH counterparts. In alkaline seawater, CoNiFeZnCr LDH@NF requires a low OER overpotential of 250 mV to reach 100 mA cm^-2 and shows a Tafel slope of 66.93 mV dec^-1. The electrode also maintains stable operation for 200 h at 100 mA cm^-2, indicating strong resistance to seawater-induced degradation. Density functional theory calculations further reveal that the quinary high-entropy configuration optimizes the adsorption behavior of *O intermediates and lowers the energy barrier of the rate-determining OER step. The improved activity and durability are therefore attributed to the synergistic electronic and structural effects arising from the incorporation of Fe, Ni, Co, Zn, and Cr into the LDH framework. This study demonstrates a practical high-entropy engineering strategy for developing robust non-precious-metal OER electrodes toward seawater-relevant hydrogen production.

Photocatalytic hydrogen evolution is an economically viable and environmentally friendly synthesis method. However, its photocatalytic efficiency is hindered by the sluggish reaction kinetics and rapid recombination of photogenerated charge carriers. Herein, an interfacial Cu‒S bond and localized surface plasmon resonance (LSPR)-synchronously mediated Cu₃P@Cu/Mn_0.3Cd_0.7S (Cu₃P@Cu/MCS) S-scheme heterojunction was designed and synthesized for accelerated photogenerated electron transfer. Under light illumination, the optimized 5%-Cu₃P@Cu/MCS composite exhibited a photocatalytic hydrogen production rate of 93.25 mmol g^-1 h^-1, representing a 7.3-fold increase compared to that of pristine MCS (12.69 mmol g^-1 h^-1). Experimental results revealed that the interfacial Cu‒S bonds between MCS and Cu₃P@Cu accelerated charge separation, thereby enhancing the reaction kinetics. Simultaneously, Cu-induced LSPR converted long-wavelength photons into localized heat, thereby increasing the interfacial temperature and accelerating the transfer of charge carriers. The synergistic effect of this chemical bond established in the S-scheme heterojunction with the LSPR effect provides new insights into photocatalytic H₂ evolution.

Organic semiconductors hold promise for photocatalytic hydrogen production, yet their performance is often limited by excitonic effects that hinder charge separation and transport. To overcome these challenges, we present a synergistic strategy combining donor-acceptor (D-A) molecular engineering with dual-surfactant-directed nanoassembly. A series of structurally analogous D-A molecules based on 4-([1,1′-biphenyl]-4-yl)-2,6-bis(4-cyanophenyl) pyridine-3,5-dicarbonitrile (CNP) were synthesized with systematic variation of donor-unit substituents. Among them, the methoxy-containing CNP, namely CNP501, exhibited a 26-fold higher hydrogen evolution rate than pristine CNP. Leveraging this, a dual-surfactant-induced self-assembly approach yielded the CNP501/DDBAB/SDBS nanophotocatalyst, which achieved an additional 12-fold enhancement in photoactivity, delivering a hydrogen production rate of 1093 mmol g^-1 h^-1 and an apparent quantum yield of 77.2% at 365 nm. The exceptional performance arises from two synergistic effects: (1) donor engineering, which modulates intrinsic molecular electric fields to promote exciton dissociation, and (2) surfactant-mediated morphological control, which optimizes hydrophilicity, minimizes interfacial charge-transfer resistance, and suppresses carrier recombination. Notably, dual-surfactant regulation uniquely enables multiple light scattering with tunable efficiency, a feature absent in single-surfactant systems.

Utilizing water as a green and abundant proton source for the photocatalytic hydrogenolysis of lignin under mild conditions represents a promising approach for biomass conversion. However, the microscopic mechanism of water activation and subsequent proton transfer remains unclear, hindering the rational design of efficient catalytic system. Herein, Mo vacancy-engineered S-scheme Bi₂Mo_1-xO₆/ZnIn₂S₄ heterojunction was constructed via a facile in-situ solvothermal process. Combining density functional theory calculations, in-situ electron paramagnetic resonance and X-ray photoelectron spectroscopy analyses reveal that the presented Mo vacancies play a dual role; they not only induce the formation of interfacial Mo-S bonds, creating atomic-level charge-transfer channels, but also drive hole localization, promoting water dissociation and generating protons for the selective hydrogenolysis of lignin C_β-O bonds. Crucially, isotope labeling experiments directly confirm that the protons generated from water dissociation serve as the direct hydrogen source for the lignin hydrogenolysis reaction. Under visible light exposure (λ > 420 nm) and an air atmosphere, the developed catalyst achieves over 90% photoconversion of 2-phenoxy-1-phenylethanol (PP-ol) lignin with a quantum yield of 5.71%, outperforming the most reported photocatalysts. Through synergistic engineering of Mo vacancies and interfacial bonds in S-scheme heterojunctions, this study provides key insights into the water-driven proton transfer mechanism in photocatalytic hydrogenolysis of lignin, highlighting an efficient biomass photoconversion strategy.

Understanding how metal oxide surfaces generate and manage reactive oxygen species (ROS) is fundamental to catalytic oxidation; however, the precise nature of active sites and reaction mechanisms remains poorly understood at the molecular level. Herein, using density functional theory calculations, we identify a novel reaction mechanism for the complete activation pathways of O₂, H₂O, and H₂O₂ to generate ROS—¹O₂, ·O₂^-, ·OH, and ·OOH—on the α-Ag₂WO₄ (110) surface. We demonstrate that undercoordinated surface silver cations act as active sites, significantly enhancing adsorption energetics and reducing activation energy barriers. Subsequently, dimethyl sulfide oxidation to sulfoxide and sulfone serves as a benchmark reaction to characterize the free energy profiles of the underlying molecular mechanism, advancing fundamental concepts in the chemistry of the α-Ag₂WO₄ (110) surface. Notably, this surface exhibits exceptional catalytic performance for H₂O₂ activation, achieving the formation of reactive intermediates ¹O₂ and ·OOH via low activation energy barriers. These consecutive stages define the most favorable pathways, where mid-gap states induce the necessary structural and electronic characteristics to stabilize paired- and unpaired-electron intermediates in the first and second steps, respectively. Collectively, these insights provide a theoretical foundation for the adsorption and activation processes governing the ROS regulation mechanism at highly reactive multifunctional surface sites, representing a significant advancement in the field of catalysis.

Strategic regulation of photogenerated carriers along with efficient utilization of full solar spectrum is a crucial approach in photocatalytic reactions. In this aspect, creating S-scheme heterojunction efficiently promotes the spatial segregation of photogenerated charge carriers for participation in photoreactions. Herein, Ag₂S/Co_1-xS@Co₉S₈@C (A-CCC) S-scheme heterojunction nanocatalysts was synthesized, demonstrating outstanding photocatalytic degradation efficiency under simulated solar light irradiation ranging from ultraviolet to near-infrared owing to strong interfacial electric field. Morphological and structural analyses via scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Raman, and in-situ-X-ray photoelectron spectroscopy confirmed the retention of the Co-ZIF-67-derived octahedral morphology with uniform Ag₂S nanoparticle distribution and formation of distinct Co_1-xS and Co₉S₈ phases embedded in a carbon matrix. Ultraviolet photoelectron spectroscopy and band gap measurements elucidated an S-scheme heterojunction configuration driven by an internal electric field, promoting interfacial charge. A steady-state THz time-domain spectroscopy in transmission mode and multi-exponential time resolved photoluminescence spectra fitting and calculated amplitude-weighted and intensity-weighted lifetimes (~2.38 ns) demonstrated significant interfacial charge separation within the 5A-CCC. The 5 wt% Ag₂S-CCC (5A-CCC) nanocatalysts endows exceptional photocatalytic activity for environmentally persistent antibiotic levofloxacin (LCN) degrading about 99.7% with an apparent rate constant of 0.0326 min^-1 in 40 min reaction duration due to extended light absorption till near infra-red region for effective solar to thermal conversion (13.6%). Radical scavenging and reactive oxygen species probe studies revealed O₂^•- as the dominant active species, participated effectively in LCN degradation. For LCN degradation, fragmentation and intermediate products were observed using liquid chromatography-mass spectrometer. This study features a highly effective photocatalytic system and offers essential insights towards full-spectrum functioning nanocatalysts for environmental detoxification of persistent antibiotics.

Photocatalytic hydrogen peroxide synthesis driven by solar energy represents a sustainable alternative to the energy-intensive anthraquinone process. However, practical efficiency is often compromised by the chemical leaching of metal species in conventional photocatalysts, which accelerates H₂O₂ decomposition during reaction. Herein, a metal-free S-scheme heterojunction is constructed via electrostatic self-assembly between a sulfonic acid-functionalized covalent organic framework (COF) and protonated g-C₃N₄. The optimized composite exhibits a markedly enhanced H₂O₂ production rate compared with pristine COF and g-C₃N₄. In-situ irradiated X-ray photoelectron spectroscopy and femtosecond transient absorption spectroscopy provide direct evidence of S-scheme charge-transfer behavior, wherein photogenerated electrons in the COF recombine with holes in g-C₃N₄, thereby preserving highly reductive electrons in the conduction band of g-C₃N₄ for efficient oxygen reduction. This work highlights metal-free S-scheme heterojunctions as an effective strategy for designing high-performance photocatalysts toward sustainable H₂O₂ synthesis.

This study provides molecular-level insights into the reactions of three ketenes (ketene, methyl ketene, and dimethyl ketene) with the BAS in MAPO-18 (M = Si, Mg) molecular sieves at operando conditions through first-principles molecular dynamics (FPMD) simulations combined with enhanced sampling techniques. Free energy surfaces constructed from FPMD simulations revealed distinct kinetic and thermodynamic preferences, linking them to different reaction routes for the production of olefins. Prior studies suggested that ketenes and their protonated analogues are key intermediates in two different pathways to olefins formation, and the three ketenes exhibited higher kinetic stability than their protonated forms in H-SAPO-18 compared to H-MgAPO-18, suggesting a high tendency for olefin production via the (cyclo)addition-decarboxylation route in H-SAPO-18. In contrast, the increased stability of the cationic intermediates and low protonation barrier for methyl and dimethyl ketenes in MgAPO-18 favor their direct decarbonylation to olefins. Surface-bound species displayed decreasing stability from surface acetate to surface propionate to surface isobutyrate, aligning with established trends for surface alkoxides. Moreover, a comparison with static calculations demonstrates their limited ability to capture the entropic contributions and dynamic effects that dominate the behavior of active intermediates under realistic reaction conditions, highlighting the necessity of molecular dynamics approaches for accurate mechanistic modeling of catalytic reactions. Benchmarking against high-level random phase approximation calculations further revealed that the revPBE-D3 functional used in the FPMD simulations may overestimate the stability of cationic intermediates but underestimate the protonation barriers of ketene. Together, these findings underscore the importance of combining dynamic simulations with accurate potential energy descriptions to reliably model active intermediates in confined microporous environments. Overall, this study provides key steps of ketene reactivity in zeo-types, bridging computational and experimental insights into CO₂-to-hydrocarbon conversion pathways. These results emphasize how subtle variations in the framework composition and substituents dictate the reaction mechanisms, offering guidance for the rational design of molecular sieves tailored for selective catalytic transformations.

The catalytic valorization of CO₂ into value-added chemicals remains a grand challenge in sustainable catalysis. Here we report a defect-tolerant two-dimensional thulium-organic framework, {[Tm(NH₂-HPPDC)(DMF)₂]·2DMF·2H₂O}_n (NUC-151), constructed through a dimensionality-reduction and ligand-functionalization strategy. Upon activation, NUC-151a develops well-ordered in-plane nanopores (14.9 × 10.7 Ų) densely populated with Lewis-acidic Tm³⁺ centers, Lewis-basic amino/pyridyl moieties, and hydrogen-bond-donating carboxyl groups. The synergistic interplay among these multifunctional sites establishes an acid-base-hydrogen-bond cooperative environment that efficiently catalyzes CO₂-epoxide cycloaddition under mild, co-catalyst-assisted conditions, affording nearly quantitative yields even under simulated dry and humid flue-gas atmospheres. Density functional theory analyses identify CO₂ insertion as the universal rate-determining step, with activation barriers following the trend -NH₂ < TmO₆ < -COOH, thereby elucidating a hierarchy of Lewis-acid activation, base-assisted charge stabilization, and hydrogen-bond facilitation. The defect-tolerant 2D architecture sustains high activity and recyclability by preserving accessible organic active sites even upon partial hydration of metal centers. This study unveils an organic-site-dominated cooperative mechanism for CO₂ fixation and provides a general design principle for moisture-resilient, multifunctional MOFs operating directly under flue-gas conditions.

Grain boundaries (GBs) in Cu-based electrocatalysts have been recognized as efficient sites producing multi-carbon chemicals (C₂₊) from CO₂ reduction, yet the effective GB regulation strategy for targeted activity enhancement is still unavailable to date, and consequently their catalytic mechanism remains unclear. Herein, polycrystalline Cu catalysts (p-Cu) with varying GB densities were fabricated by electrochemical reconstruction of mesoporous Cu₂O nanocrystals with different primary particle sizes. It is discovered that increasing GB density results in correspondingly decreased coordination number (CN) of Cu sites, which in turn contributes to the progressive enhancement of C₂₊ selectivity over the p-Cu catalysts. Specifically, the determined optimal GB density of 151 μm^-1, corresponding to a Cu CN of 6.36, delivers a remarkably augmented C₂₊ Faradaic efficiency of up to 88.06% (70.55% for C₂H₄) and a C₂₊ partial current density as high as 722.7 mA cm^-2, rendering the p-Cu ranked among the best state-of-art catalysts. Mechanism explorations disclose that increased GB density leads to lowered CN Cu sites, which are responsible for the largely amplified *CO coverage together with increased *CO_atop/*CO_bridge ratio, and enhanced localized alkaline environment, thereby boosting an energy-efficient *CO-*COH coupling pathway to produce C₂₊. This work presents a facile regulation strategy of GB density in Cu catalysts, and on this basis establishes the correlation among GB density, the CN of Cu sites, and the selectivity of C₂₊ products.

The hydrogenation of CO₂ into high-value-added chemicals represents one of the most effective strategies for mitigating the greenhouse effect and addressing the energy crisis. In this study, the incorporation of Pt into Co-based catalysts is utilized to modulate the CO competitive adsorption capacity and reaction pathways, thereby significantly enhances the C-C coupling and the selectivity of C₂₊ hydrocarbons during CO₂ hydrogenation. The formation of PtCo alloy in the catalysts is confirmed by X-ray absorption spectroscopy, in-situ X-ray diffraction, X-ray photoelectron spectroscopy and scanning transmission electron microscopy analyses. The study reveals that the presence of PtCo alloy alters the competitive adsorption behavior of CO and CO₂ on the catalyst, and enables CO to replace CO₂ as the strongly adsorbed species on the catalyst. Density functional theory calculations demonstrate that the PtCo alloy exhibits enhanced CO adsorption energy and reduced formation energy barrier for formate compared with pure Co. This is responsible for the emergence of an additional formate pathway on the PtCo catalyst. Consequently, the 2%PtCo catalyst achieves a C₂₊ selectivity of 18.5% under conditions of 350 °C and 3 MPa, markedly higher than the 1.9% over the pure Co catalyst. PtCo catalysts possesses 83.6 mmol·g^-1·h^-1 C₂₊ yield, outperforming the Fe-based reference catalyst by a factor of 4. The study presents a novel catalyst design concept for increasing C₂₊ selectivity through regulating the competitive adsorption between intermediate and reactant.

Electrocatalytic reduction of CO₂ to CO in acidic media is a compelling approach toward closing carbon cycle, as it can increase CO₂ utilization while circumvent carbonate precipitation. Nonetheless, a cardinal challenge remains the inherent competition from hydrogen evolution reaction (HER), driven by high proton availability at catalyst surface, which severely suppresses CO₂ reduction selectivity and activity. Herein, we engineer a catalyst comprising monomolecularly dispersed cobalt phthalocyanine on carbon nanohorns (CNHs) with abundant topological defects, which orchestrates efficient CO₂ electroreduction in acidic media via restricting proton transfer. This design constructs an electron-deficient Co center and surrounded with a proton-deficient microenvironment, achieving CO electrogeneration with 95.9% Faradaic efficiency (FE) and 259.1 mA cm^-2 partial current density at pH = 0.5 while maintaining > 85% FE across 38 h durability at pH 1. Mechanistic investigations reveal that the CNHs support simultaneously restricts both key proton-supply pathways: the defect-rich structure suppresses surface hydrogen spillover along the carbon framework, while the dahlia-like architecture of CNHs aggregate hinder axial hydronium diffusion from the bulk electrolyte. The resulting reduction in proton availability around Co centers, combined with limited hydronium access from the bulk, stabilizes crucial *COOH and *CO intermediates and accelerates CO₂ reduction kinetics. By showcasing how carbon-support engineering can modulate proton-transfer pathways, this work offers a viable and generalizable strategy toward high-performance CO₂ electrolysis in strongly acidic media, advancing the design of robust molecular catalysts for practical application.

TiO₂ is ubiquitous as a support in catalytic applications. However, its highly absorptive nature hampers the use of transmission-based spectroscopic techniques such as X-ray absorption spectroscopy (XAS), limiting in-situ/operando structure-activity studies. Here, we developed a combined atomic layer deposition (ALD) and surface organometallic chemistry (SOMC) approach to synthesize cobalt nanoparticles (NPs) supported on a TiO₂ thin film dispersed on SiO₂, yielding a spectroscopically accessible Co/TiO₂-SiO₂ model catalyst. The Co/TiO₂-SiO₂ exhibits CO₂ methanation activity similarly to Co/TiO₂ but in contrast to Co/SiO₂, which preferentially catalyzes the reverse water gas shift reaction. In-situ Co K-edge XAS during CO₂ hydrogenation conditions demonstrates that cobalt remains metallic, consistent with the observed methanation activity. This study highlights that combining ALD and SOMC provides a versatile platform for constructing TiO₂-supported model catalysts and enables their characterization via in situ spectroscopy.

Recently, the electrocatalytic nitrate reduction to ammonia (eNO₃RR) has become attractive as an alternative route for the green synthesis of ammonia at ambient conditions. However, the catalytic activity and selectivity of this process at low overpotentials is still low. Cu-based catalysts exhibit the best performances for eNO₃RR among all catalysts. Moreover, copper oxide catalysts, which can undergo reduction during eNO₃RR, display varied catalytic performances and facet-dependent behaviors. To elucidate the structural evolution and catalytic behavior of copper oxide electrodes, we developed an electric field-dependent equivariant machine learning potential (MLP) to simulate the evolution of electrode surfaces under electroreduction conditions. Grand Canonical Monte Carlo (GCMC) simulations were conducted to simulate the reduction of different copper oxide surfaces in reaction conditions. It was found the reduced surfaces from different oxide surfaces have different proportions of 3-fold copper and 4-fold copper active sites. Following that, the reaction mechanism of these active sites was addressed. The defective 3-fold copper sites show the best performance, indicating the Cu₂O(111) surface, which can be selectively reduced into a 3-fold-copper dominated surface at reaction conditions, should have the best catalysis performance towards eNO₃RR.

The development of sustainable synthetic routes from aldehydes to functionalized heteroarenes is an important goal in organic synthesis, owing to the low cost and ready accessibility of aldehydes. However, the high bond dissociation energy (BDE) of the Ar-C(O) bond makes the photocatalytic decarbonylative arylation of heteroarenes a formidable challenge. Herein, we report a novel photocatalytic strategy integrating photoinduced-hydrogen atom transfer (photo-HAT), photoredox, and hydrogen-bonding (HB) organocatalysis for the decarbonylative arylation/alkylation of heteroarenes using aldehydes. This method exhibits broad substrate scope across diverse heteroarenes and aldehydes, delivering products in high yields without metals or strong oxidants. Mechanistic studies show that HB-complexation between aldehydes and TFA is crucial for lowering the decarbonylation barrier. Eosin Y acts as a dual photo-HAT/photoredox catalyst, simplifying the system, while ferrocene promotes oxidative dehydroaromatization.

Nanoscale assembly-line catalysis is a novel avenue for reactions with multiple rate-determining steps. The regional coexistence of different elements in nanocomposites with adjacent heterometallic coordination can construct substructures compatible with multifunctional sites, resulting in synergistic catalysis. Herein, a novel nanocomposite with affluent Ca-O-Co-O_v-Zr micro-integrated stations (MIS) is developed through an isomorphic substitution strategy to promote the spatiotemporally ordered N-O adsorption and mitigate kinetic limitation of O transportation/desorption through an assembly-line catalytic perspective during N₂O decomposition. The optimized CoCa₆Zr₉ can achieve T₉₀ of N₂O decomposition at 355 °C and stably run for more than 100 h. This superior performance is mainly attributed to a bidirectional promotion mechanism via both “Ca-e^--Co” electronic chain in Ca-O-Co (workshop 1) and O vacancy electronic pump in “Co-O_v-Zr” (workshop 2), which promotes the formation of electron-rich Co²⁺-O_v cooperative sites (namly, the MIS), accelerating cleavage of N-O bond (Primary Step i). Meanwhile, the cooperative of atomic-regulated electronic and redox inducers can adjust the Co-O polarity to maintain the Co²⁺ valence state, weaken the Co-O bond and enhance active oxygen mobility, thus refreshing its active sites for assembly-line catalytic cycles instantly and persistently (Primary Step ii). This work establishes an effective insight for rationally assembling cooperative active sites in assembly-line inspired substructures, which is essential for advancing the research on the coordination of multiple reaction steps in complex catalytic reactions.

We report a tunable, ligand-controlled protocol for the copper-hydride-catalyzed functionalization of methylenecyclopropanes (MCPs) with allyl phosphates. This divergent methodology enables selective access to two distinct classes of unsaturated scaffolds, dictated by the specific phosphine ligand employed. When the chiral bisphosphine ligand (S,S)-Ph-BPE is utilized, the reaction proceeds via an enantioselective dihydroallylation cascade, affording nonconjugated chiral 1,9-dienes with high yields and excellent enantioselectivities (up to > 99% ee). Alternatively, switching the ligand to Xantphos confines the reaction at the ring-opening stage, selectively delivering nonconjugated 1,6-dienes via mono-allylation. Mechanistic studies support a stepwise pathway initiated by hydrocupration and β-carbon elimination, wherein the mono-allylated intermediate can be isolated and subsequently converted into the di-allylated product. The versatility of this platform is further demonstrated through a modular one-pot cascade employing two distinct allylic phosphates to generate structurally complex chiral dienes. Additionally, the catalytic system has been extended to carbonylative hydroallylation, providing efficient access to α,β-unsaturated ketones and chiral ketones. This strategy represents a robust approach for the stereoselective construction of diverse dienes and carbonyl-containing frameworks from strained ring systems.

Noble-metal-free iron-nitrogen-carbon (Fe-N-C) catalysts with well-defined FeN₄ active sites are promising alternatives to replace platinum (Pt) catalysts for oxygen reduction reaction (ORR). However, the precise design of the peripheral heteroatom-doped FeN₄ centers and the clarification of the underlying electrocatalytic ORR mechanism remain a significant challenge. Herein, we employ a coordination engineering strategy to implant two sulfur (S) atoms into the second coordination shell of the FeN₄ center (FeN₄S₂), which effectively modulates the Fe spin state via d_z²-p, d_xz-p, and d_yz-p interactions. The symmetrical S-doping in FeN₄S₂ can weaken the spin polarization of FeN₄ that induces a transition of single-Fe-atom from a high-spin to a medium-spin state, thereby optimizing the oxygen intermediates adsorption and transforming the ORR potential-determining step from *O → *OH over FeN₄ to *O₂ → *OOH over FeN₄S₂ with a lower free energy barrier, which greatly boosts the ORR performance in both alkaline and acidic media. The zinc-air battery with a FeN₄S₂ air electrode delivers a peak power density as high as 248.2 mW cm^-2 with exceptional charge-discharge stability, significantly outperforming the state-of-the-art Pt/C air electrode.

Ultrathin zeolite nanocrystals offer distinct advantages in catalysis, adsorption, and separation due to their enhanced exposure of crystal facets and improved molecular diffusion. The synthesis of ultrathin zeolites via template-free and additive-free approaches is highly desirable for sustainable and scalable production, yet remains a longstanding challenge. ZSM-5 nanosheets with a b-axis thickness as small as 10 nm were synthesized via seed-assisted crystallization in a purely inorganic aluminosilicate medium, without the use of organic templates, fluoride, or other additives. The influence of Silicalite-1 seed treatment history, a previously overlooked parameter on ZSM-5 crystallization was systematically investigated. The presence or absence of occluded organic template within the seeds critically modulates crystal morphology by affecting surface dissolution and secondary nucleation at the seed surface. Catalytic testing in methanol conversion indicates that, although structural variations due to nanoscale dimensions are minimal, differences in crystal morphology significantly influence catalytic selectivity. These findings underscore the crucial role of morphology control in tailoring the catalytic performance of zeolites.

Atomic-level dispersed metal catalysts have garnered considerable attention in heterogeneous catalysis due to their ultrahigh atomic efficiency, exceptional catalytic activity, and well-defined active site structures. However, achieving complete atomic-level dispersion of non-precious metals at high mass loadings on metal oxide supports remains a significant challenge. Here, we report the synthesis of a catalyst with highly dispersed 2.6 wt% Cu species on the tunnel-structured α-MnO₂ (MnO₂-QCu) via a quenching strategy. This approach synergistically leverages the rapid nucleation characteristic of quenching and the confinement effect of the α-MnO₂ tunnel structure. Beyond the conventional approach to catalyst loading, the activated tunnel structure of α-MnO₂ can provide additional Cu anchoring sites, effectively increasing the number of accessible catalytically active sites. The resulting MnO₂-QCu exhibits superior activity in CO oxidation, outperforming most reported Mn-based catalysts, and demonstrates excellent durability over 100 h under humid conditions. Mechanistic studies reveal that MnO₂-QCu facilitates the dual activation of lattice and molecular oxygen, while the resulting Cu-V_O-Mn interfaces promote charge transfer and enhance O₂ adsorption and activation, thereby enabling efficient and stable catalytic oxidation. This work offers a general and feasible route to design high-loading single-atom catalysts on oxide supports for energy and environmental applications.