ABSTRACT: Halide perovskites (HPs) have emerged as compelling candidates for photocatalysis, owing to their exceptional optoelectronic properties, including tunable bandgaps, high optical absorption coefficients, and long charge carrier lifetimes. Nevertheless, the reliance on light alone can constrain their catalytic efficiency and utilization of solar energy. To address this challenge, hybrid photocatalysis, where additional stimuli such as electric or (photo)thermal fields are integrated with the pristine light field, has garnered increasing attention. This review systematically evaluates hybrid catalytic strategies for HP-based photocatalysis, with a particular emphasis on enhancement mechanisms arising from synergistic multi-physical field interactions. Subsequently, we highlight recent advances in HPs-based photothermal catalysis (PTC) and photoelectrocatalysis (PEC), critically assessing persistent technical challenges and summarizing design principles for materials and device configurations, while other multi-field strategies including piezo- and magnetic -assisted photocatalysis are also discussed. Finally, we outline the key challenges facing HP-based hybrid photocatalysis and propose future research directions spanning from micro-level material design to macro-scale system integration. This review aims to offer fundamental insights and theoretical guidelines for designing stable and high-performance hybrid photocatalytic systems, thereby advancing the practical application of HP-based technologies.

Lignin, one of the most abundant and renewable components of biomass, represents a promising feedstock for sustainable biofuel production. Photocatalytic conversion offers an efficient, environmentally benign, and mild route for lignin depolymerization. Transition-metal-based photocatalysts, in particular, enable precise modulation of photogenerated charge carriers and the creation of highly active catalytic sites, thereby facilitating selective lignin transformation while preserving its valuable aromatic motifs. Despite rapid advances, comprehensive reviews on transition metal-based photocatalysts for lignin-to-fuel conversion remain limited. This review systematically summarizes recent progress in transition-metal-based photocatalytic lignin valorization for both gaseous fuels and liquid fuel precursors. We analyze the key bond-cleavage mechanisms using lignin model compounds, uncovering structure-activity relationships between transition-metal catalysts design and lignin depolymerization behavior, and highlight the current challenges hindering practical applications. Furthermore, the synergistic interactions between photocatalytic routes to liquid and gaseous fuels are discussed. Finally, strategies for upgrading lignin-derived intermediates into usable fuels are evaluated, with attention to their technical, economic, and environmental feasibility. Overall, this review offers new insights and theoretical guidance for advancing transition metal-based photocatalytic systems toward efficient and sustainable lignin-to-biofuel conversion.

The rapid increase of the concentration of atmospheric CO₂ and the imperative for solar-fuel generation highlight the urgent need for advanced catalytic materials. Single-atom catalysts (SACs) anchored on two-dimensional (2D) materials present a powerful approach by combining atomically isolated active sites with tunable coordination environments, defect chemistry, and enhanced charge-transport pathways intrinsic to 2D supports. This review explores SAC/2D systems for photocatalytic CO₂ reduction, beginning with the fundamental thermodynamics and kinetics of CO₂ activation, multielectron proton-coupled transfer, hydrogen-evolution competition and C₁ vs. C₂⁺ product selectivity. Then, it covers synthesis strategies for anchoring atomically dispersed metal sites on 2D supports, and discusses advanced characterization techniques‒including atomic-scale imaging, operando coordination spectroscopy and time-resolved carrier-dynamics measurements; that link structure and photocatalytic function. Photocatalytic performance trends across carbon-based, metal-oxide and emerging 2D supports are analysed to illustrate how planar confinement, support polarity, interfacial coupling, and charge-carrier behaviour regulate activity, selectivity, and stability. Further, a unified design framework is established, and three framework-guided design strategies i.e., heteronuclear dual-atom sites, heterostructure interfaces and internal-field/polarization engineering, are highlighted as promising strategy to overcome several intrinsic and scale-up challenges i.e., single atom instability, low multicarbon (C₂⁺) selectivity and rapid recombination. Finally, by aligning mechanistic insight with material design and pointing toward reproducible high-loading synthesis and device-oriented configurations (e.g., thin-films, flow-reactors), the review outlines a pathway toward selective, stable and scalable SAC/2D photocatalyst systems for solar-driven CO₂ reduction.

Nitrate reduction reaction (NO₃RR) and C-N coupling reaction with nitrate as precursor has the possibility to provide sustainable solutions for environmental remediation and chemical syntheses. By replacing anodic oxygen evolution reaction (OER) with alternative oxidation reactions, pollution control can be improved and energy efficiency can be enhanced. In this review, the latest trends in NO₃RR and C-N coupling reactions to obtain chemicals are evaluated by using the technology readiness level (TRL) and mechanisms of nitrate reduction and C-N reactions including the formation intermediates and active sites in various metal-based electrocatalysts are discussed. Research progress in coupled NO₃RR electrolysis systems and anodic oxidation reactions are analyzed with respect to catalyst design, pairing mechanisms and TRL to recommend feasible reaction combinations. Techno-economic analysis indicates that NO₃RR paired with biomass conversion or waste plastic upgrading are attractive, as they can reduce production cost of NH₃ and convert resources into value-added chemicals. The TRL analysis reveals that some coupling systems are close to TRL 5 stage, while the long-term operational stability of electrocatalysts remains a key bottleneck on the path to industrialization. Nevertheless, challenges still exist in chemical separation through steps such as evaporation, crystallization and extraction so as to achieve high utilization of waste resources. Electrochemical scale-up and operation of continuous-flow electrolyzers with actual waste streams along with mass production of catalysts presents new challenges that may be met through the demonstration system study of TRL 5+.

In recent years, oxygen-centered organic radicals (OCORs) have garnered significant attention for their pivotal roles across diverse chemical and material science platforms. As a unique class of open-shell molecules, OCORs exhibit remarkable stability and highly tunable reactivity, enabling innovative possibilities for organic transformations and the design of advanced functional materials. Unlike conventional short-lived radicals, OCORs can maintain their stability for several months in complex environmental conditions while showcasing exceptional efficiency in catalytic processes. Their versatility extends to a range of applications, including environmental remediation, redox-active materials, and next-generation energy systems. This review provides a comprehensive summary of recent advancements in OCORs research, focusing on their characterization techniques, synthesis methods, and applications in electronic structure modulation and functional material design. Additionally, it highlights key challenges such as enhancing stability, selectivity, and scalability while proposing future research directions. These insights aim to foster deeper understanding and innovation, propelling the development of OCORs for broader scientific and industrial applications.

Solar-driven synthesis of hydrogen peroxide (H₂O₂) using semiconductor-based catalysts for practical applications is hindered by intrinsically inefficient separation and transfer of charge carriers, and rapid H₂O₂ decomposition. Herein, we designed a sulfur (S)-doped g-C₃N₄/ZnO Z-scheme heterojunction, wherein an amorphous ZnO₂ layer is in-situ formed during photocatalysis reaction (denoted as S-ZnO/ZnO₂@CN), to achieve robust H₂O₂ production. Mechanism analysis reveals that S doping enhances the built-in electric field to promote efficient charge carrier separation and induces sp²→sp³ hybridization reconstruction in g-C₃N₄ to create electron-rich active sites that accelerate O₂ reduction kinetics and stabilize the critical *OOH intermediates. Concurrently, the in-situ formed ZnO₂ layer on the S-doped ZnO surface dynamically passivates decomposition-prone sites through Zn-O₆ terminal coordination, spatially isolating reactive intermediates and suppressing H₂O₂ decomposition via Fenton-like cycle inhibition. The triple synergy between S-tailored charge dynamics, ZnO₂-enabled interfacial protection and strengthened Z-scheme built-in electric field maximizes charge separation and transfer while stabilizing the generation of H₂O₂, thereby resulting in a robust H₂O₂ production (13.8 mmol/(g·h), reaching 9 mmol/L within 2.5 h, apparent quantum yield: 32.4% at 365 nm). This work establishes a “triple-channel regulation” paradigm toward high activity with operational stability in solar-driven chemical synthesis.

Photocatalytic hydrogen evolution represents a sustainable and promising avenue for clean energy generation through harnessing solar energy. This study presents a photocatalytic system Fe₁₁POM@CQD@Zn_0.5Cd_0.5S, designed to enhance photocatalytic hydrogen evolution while addressing persistent environmental challenges. This advanced composite synergistically integrates iron polyoxometalate Na₂₇[Fe₁₁(H₂O)₁₄(OH)₂(W₃O₁₀)₂(α-SbW₉O₃₃)₆] (Fe₁₁POM) with carbon quantum dots (CQD) and a zinc cadmium sulfide (Zn_0.5Cd_0.5S) matrix, optimizing charge separation and light absorption efficiency. This composite exhibits a remarkable hydrogen production rate of 32.18 mmol·g^-1·h^-1, accompanied by a turnover number of 32,394 and a turnover frequency of 10798 h^-1. Notably, the apparent quantum yield reaches approximately 40%, while the solar-to-hydrogen efficiency is measured at 1.69%. The synergistic integration of Fe₁₁POM, the CQD and Zn_0.5Cd_0.5S components optimizes charge separation and transfer, significantly enhancing photocatalytic activity. This innovative approach provides a promising strategy for developing high-performance photocatalysts for sustainable hydrogen production, offering insights into the design of efficient heterostructures to address crises of energy scarcity and environmental pollution as well as pave the way for future research in multifunctional photocatalytic systems.

Quantum dots (QDs) demonstrate significant potential in the field of photocatalytic hydrogen production due to their unique photoelectronic properties. In this study, based on the successful synthesis of Ag₂S QDs, a rationally designed CoWO₄/Ag₂S S-scheme heterojunction was constructed by utilizing the band structure and Fermi level difference between CoWO₄ and Ag₂S QDs. Simultaneously, an efficient full-space electric field was engineered on the Ag₂S QDs-modified CoWO₄ photocatalyst through charge polarization strategy. Specifically, this robust full-space electric field was formed via cascaded coupling of the bulk electric field and the interface electric field. The successful establishment of both the CoWO₄/Ag₂S S-scheme heterojunction and the full-space electric field was confirmed through characterization techniques including femtosecond transient absorption spectra, Kelvin probe force microscopy and in-situ X-ray photoelectron spectroscopy, along with density functional theory calculation results. Under the synergistic effect of the continuously driven full-space electric field and the S-scheme heterojunction, the separation of photogenerated electrons and holes has been significantly enhanced, enabling substantial electron accumulation on the catalyst surface for reaction participation, thereby greatly improving charge utilization efficiency. Meanwhile, it greatly facilitates the participation of highly oxidizing-reducing capable photogenerated electrons and holes in the reaction, providing sufficient driving force for the hydrogen evolution reaction. Ultimately, the hydrogen production rate of CWAS-10 reached 1546.23 μmol·g^-1·h^-1 within 5 h. Compared with the original CoWO₄ and Ag₂S, the performance was improved by nearly 2.6 and 4.2 times, respectively. This study offers a novel strategy for constructing S-scheme heterojunctions via quantum dot modification and synergistically regulating charge dynamics, providing valuable insights for the design of efficient photocatalysts in the field of energy conversion.

The generation of active hydrogen species (H*) is an essential step in the photocatalytic conversion of nitrogen molecules (N₂) to ammonia (NH₃). Metal-organic frameworks (MOFs) are versatile porous structures but they do not exhibit sufficient photocatalytic activities for nitrogen fixation. Adding appropriate amounts of noble metal species as a cocatalyst to MOFs can often improve their activities. This work uses a photoreduction strategy to reduce the right amount of Pt⁴⁺ to Pt clusters, and confines the remaining Pt⁴⁺ uniformly onto DUT-67(Zr). This is realized by taking advantage of a unique Pt-S electron channel, and the unsaturated Zr sites are concurrently in-situ generated under light exposure. The unsaturated Zr sites adsorb and activate N₂, while the Pt clusters are involved in the water splitting process on DUT-67(Zr) to generate more H*, leading to continuous H* supply that would speed up the catalytic hydrogenation of nitrogen intermediate NH_x. The Pt-S electronic channel formed between highly dispersed single atoms Pt and DUT-67(Zr) facilitates the separation and transfer of photo-generated charge carriers. Consequently, with the synergistic effect of unsaturated Zr sites, Pt clusters and Pt-S electron channels, a high photocatalytic nitrogen fixation performance of 78.8 μmol g^‒1 h^‒1 can be achieved. This is 10.4 times higher than that of the sample DUT-67-L with only unsaturated Zr sites and no Pt loading. This work provides an insight to rational design of uniform dispersed precious metal-based MOF photocatalyst for efficient photocatalytic ammonia synthesis.

Atomically precise metal clusters, as an advantageous platform for investigating the active site architectures and catalytic mechanisms, remain largely underexplored. Here, we demonstrate that carbonyl-rich metal clusters (CRMC) serve as exemplary electrocatalytic platforms, enabling highly efficient and selective electroreduction of nitrate to ammonia under neutral aqueous conditions. To establish a comprehensive structure-performance correlation, we systematically investigated an array of diverse carbonyl-rich metal clusters, including Co₂-CRMC, Co₄-CRMC, Ru₃-CRMC, Fe₂-CRMC, Fe₃-CRMC, Mo-CRMC, W-CRMC and Mn₂-CRMC. Among them, Co₂-CRMC electrode delivered exceptional performance, with a Faradaic efficiency of 97.2% and an ammonia yield rate of 150.5 mmol h⁻¹ g⁻¹_cat., while Co₄-CRMC electrode achieved a Faradaic efficiency of 98.7% and a yield rate of 129.2 mmol h⁻¹ g⁻¹_cat.. Theoretical calculations and mechanism studies reveal that the high catalytic activity stems from enhanced NO₃⁻ adsorption and a reduced energy barrier for the *NO hydrogenation steps. Furthermore, electrostatic potential analyses highlight the critical role of metal-carbonyl ligand interactions in optimizing the electronic environment of metal centers, facilitating stronger NO₃⁻ adsorption. This research offers a profound molecular-level understanding for the design of sophisticated metal-cluster catalysts, opening avenues for efficient nitrogen cycling processes and environmental restoration efforts.

The decarbonization of the ammonia (NH₃) synthesis industry demands the development of energy-efficient and sustainable processes. Among various emerging approaches, non-thermal plasma (NTP) catalysis shows significant promise for overcoming the sluggish kinetics of nitrogen (N₂) activation under mild conditions while minimizing carbon emissions. Growing evidence suggests that plasma-derived hydrogen radical (H•) can serve as powerful reducing agent and direct hydrogen source to activate N₂ molecules in the gas phase. However, the efficient and sustained generation of H• species typically relies on high-power plasma dischages, leading to excessive energy consumption. In this study, we introduce a metal hydride-enhanced plasma catalysis strategy, in which TiH₂, CaH₂, and LiH act as hydrogen donors, releasing lattice hydrogen atoms as H• radicals while generating hydrogen vacancies on the surface. These vacancies are rapidly replenished by H₂ molecules, establishing a self-sustaining hydrogen-release/replenishment cycle that continuously supplies reactive H• species. As a result, this approach achieves an untrahigh NH₃ yield of 360.9 mg·h^-1·g^-1 and an energy efficiency of 9.02 g·kWh^-1 at room temperature and atmospheric pressure, surpassing most reported catalytic systems. Mechanistic studies reveal that the release of lattice hydrogen is the rate-determining step, while N₂ hydrogenation proceeds with a remarkably low energy barrier of 0.123 eV. These findings highlight the potential of metal hydrides as effective catalysts for plasma catalysis and provide valuable guidelines for the development of future catalysts aimed at energy-efficient activation of inert molecules.

Robust metal-support interactions are crucial for designing efficient and corrosion-resistant electrocatalysts, as they significantly enhance charge separation and catalytic activity while also improving the stability and atomic utilization of metal catalysts. Here, we reported a temperature-regulated synthesis strategy to fabricate a self-supporting Ru/B,N co-doped MoO₂ electrocatalyst on a CNT framework (RBNM/CNTs₅₀₀), designed to simultaneously enhance catalytic activity and durability under practical electrolyzer conditions. The RBNM/CNTs₅₀₀ featured a unique nanostructure with excellent conductivity and strong chemical stability, while oxygen-vacancy-rich MoO₂ units at the interface reinforced metal-support interactions. This architecture stabilized Ru species during the OER and facilitated proton transfer, thus accelerating HER kinetics as confirmed by density functional theory calculations. As a result, RBNM/CNTs₅₀₀ exhibited outstanding bifunctional electrocatalytic performance, achieving exceptionally low overpotentials of 9 mV for the HER and 166 mV for the OER at 10 mA cm^‒2, along with superior overall water-splitting activity characterized by a low cell voltage of 1.42 V and stable ampere-level operation at 10, 1000, and 2000 mA cm^‒2 in alkaline media. When integrated into an anion-exchange membrane water electrolyzer, RBNM/CNTs₅₀₀ demonstrated exceptional durability and surpassed benchmark electrocatalysts in performance. This study offers mechanistic insights into defect engineering and underscores a rational design approach for next-generation energy conversion devices.

This paper proposes a multi-level structure design strategy, a dense cobalt oxide layer (d-Co₃O₄), a cobalt oxide catalytic layer (h-Co₃O₄), and an amorphous molybdenum oxide (a-Mo_xO_y) co-catalytic layer are constructed layer by layer on nickel foam (NF) through the combination of electro-deposition and oxidation. The a-Mo_xO_y/h-Co₃O₄/d-Co₃O₄/NF composite catalyst with both high catalytic activity and high stability was thus prepared. The main function of the d-Co₃O₄ layer is to prevent NF from coming into direct contact with acidic media to stop its electrochemical corrosion. The h-Co₃O₄ catalytic layer thus acquires a larger specific surface area, thereby exposing more active sites. The main function of the a-Mo_xO_y co-catalytic layer is to regulate the electronic structure on the surface of h-Co₃O₄, reduce the electron cloud density of the Co active sites, and thereby promote the adsorption and oxidation of the oxygen in a water molecule on it. The electrochemical test results show that the overpotential of a-Mo_xO_y/h-Co₃O₄/d-Co₃O₄/NF at a current density of 10 mA cm^-2 is 254 mV, the Tafel slope is 118 mV dec^-1, and the stability exceeds 12 h in 0.5 mol L^-1 H₂SO₄. Raman, X-ray photoelectron spectroscopy characterization and theoretical calculations indicate that the a-Mo_xO_y-Co₃O₄ interface promotes the transfer of electrons from Co to Mo, optimizes the electronic structure of the active site, and reduces the adsorption and desorption energy barriers of the reaction intermediates OOH*, OH* and O*, thereby enhancing the oxygen evolution reaction performance of the catalyst. This study provides a new structural design strategy for constructing stable transition metal-based oxide catalysts on NF for acidic oxygen evolution reaction.

Electrochemical H₂O₂ synthesis via the two-electron oxygen reduction reaction (2e^- ORR) offers a green alternative to the energy-intensive anthraquinone process, but its practical viability is hindered by the sluggish and low-value oxygen evolution reaction (OER) at the anode. Here, we present an energy-saving paired electrolysis strategy that replaces anodic OER with methanol oxidation reaction (MOR) using a ternary Mn-doped NiCo layered double hydroxide (Ni_0.50Co_0.30Mn_0.20 LDH) catalyst in situ grown on nickel foam (NF) by a one-step hydrothermal method. The optimized catalyst achieves a low MOR potential of 1.32 V_RHE at 10 mA cm^-2 and a formate Faradaic efficiency of 92.9%, outperforming its undoped counterpart (Ni_0.61Co_0.39 LDH, 1.37 V_RHE and 83.3%). In-situ Raman spectroscopy and density functional theory calculations reveal that Mn doping lowers the energy barrier for the Ni²⁺/Ni³⁺ redox transition, facilitating the generation of catalytically active Ni³⁺ species. When coupled with graphitized hydroxyl-functionalized multi-walled carbon nanotubes coated on carbon paper (CNTs@CP) as the 2e^- ORR cathode in a two-electrode electrolyzer, at the operation condition of 50 mA cm^-2, the 2e^- ORR||MOR system delivers a cell voltage reduction of 254 mV, enabling a 10.3% decrease in energy consumption for H₂O₂ production, compared with the conventional 2e^- ORR||OER system. Moreover, the simultaneous generation of value-added formate at the anode yields a 97.9% increase in net economic benefit. This work establishes a generalizable paired electrolysis paradigm for the decentralized, energy-efficient, and economically viable co-production of H₂O₂ and high-value chemicals.

The integrated CO₂ capture and conversion through oxidative dehydrogenation of ethane (iCCC-ODHE) utilizes the captured CO₂ as a mild oxidant to promote value-added ethylene production. Nevertheless, it is still trapped by low efficiency owing to little understandings about the synergistic interaction between the CO₂ capture and catalytic ODHE. Herein, we focus on exploring the contributions of local catalytic environments to the iCCC-ODHE performance through tailoring the catalyst itself and the proximity-governed effect. The Co-ZSM-5 catalysts are developed to achieve a selective cleavage of the C-H bond over the C-C bond in C₂H₆ through modulating the relative concentration of Co²⁺. When coupling the optimized Co-ZSM-5 catalyst with the CO₂ adsorbent Ca₄MgO₅ by adjusting packing configurations in a fixed bed, a superior iCCC-ODHE performance with an excellent CO₂ capture capacity of 10.8 mmol g_adsorbent^‒1 and a remarkable C₂H₄ yield of 45.4% is achieved at 650 °C in the granule-stacking configuration. Consistently, the density functional theory calculations reveal the pathway of these abnormal phenomena that the low local CO₂ concentration around catalytic sites, corresponding to a relatively far proximity distance, shows a significant effect on decreasing the reaction energy of selective cleavage of the first C-H bond in C₂H₆. Meanwhile, the produced *H species can be consumed by the following adsorbed *CO₂, facilitating the shift of reaction equilibrium forwardly for the formation of C₂H₄ and CO. Therefore, this insight into the local catalytic environment provides a promising iCCC-ODHE strategy toward carbon neutrality.

Understanding and guiding the dynamic structural evolution of electrocatalysts under operating conditions is essential for advancing high-performance energy conversion systems. Herein, we report manganese-doped nickel selenide (Mn/NiSe₂) as a model platform to elucidate that dopant-induced reversible phase transitions suppress the irreversible over-oxidation of γ-phase nickel oxyhydroxide (γ-NiOOH), thereby achieving superior urea oxidation reaction (UOR) performance (with a low onset potential of 1.26 V vs. RHE) and accelerating urea-electrolysis hydrogen generation (284.8 μmol h^-1, 3.9 times that of pristine NiSe₂). In-situ Raman spectroscopy reveals that Mn acts as a dynamic phase-transition trigger, modulating the local electronic structure of NiSe₂ to promote its electrochemical reconstruction into highly active γ-NiOOH, and inducing a reversible γ-β structural regeneration during UOR. Density functional theory calculations further show that Mn doping optimizes the electronic state distribution of nickel sites, significantly strengthens urea adsorption (adsorption energy increases from -2.09 to -4.66 eV), and lowers the energy barrier for N-H bond cleavage in the key CO(NH₂·NH₂)* intermediate (from 3.45 to 3.11 eV). This work establishes a dopant-triggered dynamic phase regulation paradigm, and provides a novel strategy for designing self-adaptive electrocatalysts for complex energy conversion reactions.

Hydroxyl radicals (•OH) are crucial in the photocatalytic oxidation of methane (CH₄) to methanol (CH₃OH) at room temperature. Hydrogen peroxide (H₂O₂) is generally employed to drive CH₄ oxidation by providing •OH radicals; however, its practice use is often limited by high cost and handling challenges. Here we report a Zr-based metal-organic framework material modified by amino groups (U-NH₂), which severs as a noble-metal-free catalyst enabling visible light absorption and electron density redistribution. The U-NH₂ catalyst performs outstanding in-situ photosynthesis of H₂O₂ with O₂ under visible light in a sacrificial-agent-free system, achieving an H₂O₂ yield up to 189 µmol g^-1. Molecular dynamics simulations reveal that O₂ preferentially accumulates near the amino-functionalized pores of U-NH₂, creating localized O₂-enriched microenvironments that are critical for efficient H₂O₂ synthesis. The in situ synthesized H₂O₂ promotes the generation of •OH radicals, driving CH₄ oxidation to CH₃OH. Remarkably, highly selective generation of CH₃OH is achieved with a selectivity of near 100% and a yield of up to 412 mL g_cat^-1 per concentration of H₂O₂. Our finding opens up an appealing avenue for efficient solar energy activation of CH₄ to generate CH₃OH at ambient temperatures.

The direct conversion of methane (CH₄) into higher-value C2 products is essential for the green and efficient conversion of clean energy. However, this conversion process faces significant challenges due to the difficulty in activating methane's C-H bonds and the complexity of controlling C-C coupling reactions. Herein, we design and construct the unsaturated metal Zr⁴⁺ site by introducing ligand defects in UiO-66 through treatment with trifluoroacetic acid (TFA), which enables the direct oxidation of methane to acetic acid using H₂O₂ under mild conditions. Remarkably, a volcano-shaped correlation was observed between the degree of ligand defects in UiO-66 and acetic acid selectivity. Under optimal conditions (150 °C), the catalyst achieved an outstanding acetic acid selectivity of 84% with a high yield of 1691 μmol·g_cat.^-1. Notably, the catalyst exhibited exceptional stability, maintaining its performance over at least five consecutive reaction cycles. Through TFA modulation, the d-band center of the Zr 3d orbital in Zr⁴⁺ sites exposed by UiO-66 shifts upward. This promotes the decomposition of H₂O₂, thereby facilitating the formation and stabilization of highly reactive Zr-OH species, which enhances the activation of C-H bonds in CH₄. The resulting *CH₃ species is further oxidized by *OH species into *COOH species, which undergo stable C-C coupling at exposed Zr⁴⁺ sites to produce acetic acid. This work provides novel insights into the design of highly efficient catalysts for the direct conversion of methane into C2 oxygenates compounds under mild conditions.

The direct conversion of methane to methanol (DMTM) is a key technology for the efficient utilization of natural gas resources, which remains a significant challenge in heterogeneous catalysis. Here, we report the selective catalytic oxidation of methane over Cu-KFI zeolites in a continuous CH₄-H₂O-O₂ reaction system. A high methanol space-time yield of ~3120 mmol/mol_Cu/h with methanol selectivity of 71% is achieved with a low Cu loading of 0.34 wt% at 550 °C via regulating O₂/H₂O ratio. Such a high-performance catalyst further shows a highly-stable catalytic activity in a longtime continuous operation under high water content (~12.2%). The isotope labelling with H₂¹⁸O and ¹⁶O₂ reveals that O₂ is the dominant oxygen source while water is also the oxidant for methane selective oxidation. Reaction analysis indicates that high reaction temperatures (> 450 °C) and high O₂ concentrations (> 1000 ppm) lead to an apparent overoxidation and side reactions of methane into CO₂ and CO. Fortunately, this phenomenon can be inhibited via increasing water vapor content, which, however, is ineffective at higher O₂ concentrations (e.g., 5000 ppm). Besides, the present study also reveals that the catalytic performance of Cu-KFI zeolites is related to both the Cu site sizes and ring window sizes based on the experimental results and density functional theory calculations. This work evidences a great potential of Cu-KFI zeolites with low Cu loadings in methane-selective conversion to methanol and provides an insightful understanding of continuous catalytic CH₄-H₂O-O₂ reaction system.

Selective hydrogenation of furfural (FFL) to furfuryl alcohol (FAL) represents a pivotal paradigm in sustainable biomass valorization. In this work, nanoscale Cu clusters were encapsulated in silicalite-1 (S-1) zeolite using in-situ synthesis, and further modified by a rare-earth element of La for regulating the catalyst microenvironment. The obtained La-Cu@S-1 can provide an enhanced performance in the FFL-to-FAL transformations, with 98.6% conversion of FFL and 99% selectivity of FAL at 110 °C, 20 bar H₂, and 3 h. Besides, La-Cu@S-1 shows a good stability without apparent catalyst deactivation upon four consecutive runs. Extensive characterization research reveals that La addition could provide anchoring sites for Cu nanoclusters via an enhanced electronic interaction, thereby effectively suppressing metal leaching and agglomeration during the liquid-phase catalysis. Additionally, La addition could modulate the zeolite microenvironment of encapsulated Cu nanoparticles and notably stabilize the conventionally unstable Cu⁺ species at a high proportion, even in a reductive H₂ atmosphere during catalysis, accounting for the enhanced activity and stability. This study showcases La modification as an efficient approach to rationally develop metal-zeolite combinations with enhanced performance, promoting potential utilization and development of rare-earth elements in the valorization of biomass and other renewable energy.

The synthesis of KA oil (a cyclohexanone-cyclohexanol mixture) from guaiacol through mild electrocatalytic approach represents a sustainable strategy for biomass valorization. Herein, we report the electrocatalytic conversion of guaiacol to KA oil over the reduced Pt/TiO₂ catalysts. The TiO₂-induced hydrogen spillover effect facilitates strategic modulation of H_ads (H*) coverage on Pt surfaces, thereby effectively suppressing competitive aromatic ring hydrogenation and excessive hydrogen evolution reactions. Comparative studies of electrocatalysis and thermocatalysis have demonstrated that Pt active sites serve as the dominant catalytic centers. However, H spillover significantly influences reactivity and selectivity, particularly in the electrocatalytic pathways. The electrocatalytic system demonstrates preferential C-O bond cleavage with KA oil selectivity around 70%. This work provides valuable insights into the regulation of metal-support interactions in the design of electrocatalysts.

Chemical recycling of plastics is emerging as a powerful strategy to tackle global plastic waste while generating high-value chemicals. In this study, we unlock the potential of Ga-promoted, structurally engineered zeolites to convert polyolefins into aromatics by tailoring acid-site properties. Commercial ZSM-5 was reimagined into shell-layer (HZ5@s1), hollow (HZ5-hol), and mesoporous (HZ5-meso) architectures, followed by Ga incorporation. Our experiments reveal how structural tuning boosts olefin production, while Ga dramatically enhances monocyclic aromatic hydrocarbons (MAH) yields—up to 63 wt% for Ga-HZ5. Catalyst performance trends highlight the synergy between architecture and Ga loading, with Ga-HZ5-hol delivering the highest combined yield (30 wt% MAH + 51 wt% light olefins) after 100 consecutive runs. Despite Ga deactivation, acid sites remain robust, shifting product selectivity toward olefins and 1,3-cyclopentadiene. Regeneration slightly reduces aromatization but improves olefin output, while less reducible GaO_x species suppress aromatic formation. Mechanistic insights reveal that butene/propylene conversion governs MAH formation, and ethylene yield correlates with acid site density—positively for Ga-free catalysts, inversely after Ga loading. These findings pave the way for the design of next-generation zeolite catalysts for efficient plastic upcycling.

The reduction of NO with CO is a key reaction in emission control and heavily relies on the use of noble metal catalysts. Reducing the catalyst cost without compromising the activity and selectivity is still a challenge. In this work, we design a PtNi₄₀ single atom alloy (SAA) catalyst featuring Pt single atoms uniformly distributed in a Ni matrix supported on TiO₂ nanosheets. The PtNi₄₀/TiO₂ catalyst exhibits superior performance compared to its monometallic and random alloy counterparts, achieving complete NO conversion and 100% N₂ selectivity at 250 °C and outstanding stability over a 100-h run. High angle annular dark field scanning transmission electron microscopy imaging, X-ray absorption fine structure, in-situ diffuse reflectance infrared Fourier transform spectroscopy and X-ray photoelectron spectroscopy characterizations reveal a distinctive synergy between the two metals. Pt single atoms are negatively charged due to remarkable electron transfer from Ni to Pt, and NO dissociation occurs on Ni ensembles whereas CO is preferentially adsorbed on electron-rich Pt single atoms. The reaction of NO+CO proceeds over the Pt-Ni SAA structure with a much lower barrier compared to monometallic Pt catalyst, demonstrating the unrivalled capability of SAA for enhancing the activity and selectivity with much reduced use of noble metals.

Phenol is a common organic pollutant in industrial wastewater and must be strictly controlled and discharged to meet standards to prevent ecological health risks. Traditional Fenton method faces challenges such as low utilization of active sites in iron-based catalysts, leaching of metallic iron, and limited pH adaptability. In this work, we introduce a solid-grinding followed by heat-treatment (SH) method for the synthesis of iron single-atom catalysts (SACs). This approach leverages the unique constrained space which is between the silica walls and the template within template-loaded SBA-15 (TLS). The precursor Fe(NO₃)₃ is able to penetrate the constrained space through solid-grinding. During the following heat treatment process, iron single atoms are formed and stabilized in the in-situ carbon layers formed by the template, resulting in the formation of a novel SAC, named as Fe₁@C-TLS. Experiments and theoretical calculations reveal that the constrained space effectively inhibits the migration and agglomeration of iron atoms to form a unique Fe-C₃ coordination structure. The Fe₁@C-TLS catalyst exhibits excellent activity (k = 0.102 min⁻¹) in the Fenton reaction for the degradation of phenol, significantly outperforming the Fe@TRS nanoparticle catalyst prepared without constrained space (k = 0.0115 min⁻¹), as well as reported iron and other transition metals-based catalysts.

Epoxides are crucial intermediates in fine chemical production, but existing synthesis processes suffer from issues such as pollution, long process flows, or safety risks. Linking molecular oxygen activation and olefin epoxidation through active hydrocarbons as a bridge is a feasible pathway; this method typically involves effective C-H dehydrogenation to form active free radicals, which then couple with molecular oxygen to achieve subsequent selective oxidation. However, the design of catalysts capable of efficiently regulating the oxidative activation of C-H bonds to generate key intermediates for olefin epoxidation remains challenging. Herein, we designed a metal porphyrin-based COF catalyst (Ru-COF-TPD) and, using air as the oxidant, constructed a catalytic system for olefin epoxidation via the oxidation relay of adamantane. Ru-COF-TPD features highly dispersed metal atoms, excellent stability, and tunable pore sizes. Under an air atmosphere, it can activate the C-H bonds of adamantane to in-situ generate peroxy species and regulate active oxygen transfer, thereby enabling selective olefin epoxidation. It achieves 83% conversion for 1-butylene with 81% selectivity to the corresponding epoxide, and exhibits good activity towards various olefins. After the reaction, the metal sites remain dispersed, indicating good structural stability of the catalyst. This tandem system is an endothermic and disordered, following a pseudo-first-order model with an apparent activation energy of 108.08 kJ/mol. It was further found that Ru-COF-TPD generates carbon-centered radicals by activating the C-H bonds of adamantane, which then combine with oxygen to form peroxy radicals, and regulates the epoxidation process high-valence Ru=O intermediates. The catalytic system established in this study is safe, economical, and efficient, providing a lab-scale protocol for olefin oxidation with air.

Chemoenzymatic ketone formation-conversion cascades represent a powerful strategy in asymmetric synthesis, yet their efficiency is often limited by catalytic incompatibility and poor operational sustainability. Here, we develop a continuous-flow concurrent chemoenzymatic cascade that integrates a metal-catalyzed Heck coupling of aryl iodides with allylic alcohols (for ketone formation) and an enzymatic asymmetric reductive amination of the resulting ketones, enabling efficient one-pot access to chiral γ-arylamines. The cascade is powered by a bimetallic-bienzyme-cofactor co-immobilized catalyst, which is constructed by spatially incorporating palladium-iron nanoalloy catalysts and a cofactor-self-sufficient biocatalytic system consisting of an amine dehydrogenase, a glucose dehydrogenase and phosphorylated NADH on polydopamine-coated, quaternary-ammonium-functionalized mesoporous organosilica nanoflowers. Implementing this integrated catalyst in a continuous-flow system offers a cost-effective and sustainable platform for asymmetric amine synthesis, delivering markedly enhanced overall catalytic efficiency, high space-time yield, and excellent operational stability.

Previously, chiral bis-amino-bis-pyridylmethyl and structurally related Mn complexes have been reported to mediate a variety of highly enantioselective biomimetic oxidative transformations of C=C groups with hydrogen peroxide, such as epoxidations, syn-1,2-dihydroxylations, and syn-1,2-hydroxy acyloxylations. Herein, we present one more facet of their versatile catalytic reactivity which enables the enantioselective conversion of olefinic substrates to the corresponding vicinal syn-hydroxy azides in up to 96% ee. The data collected here provide evidence in favor of the direct regio- and enantioselective vicinal syn-hydroxyazidation of the substrate, using H₂O₂ as terminal oxidant and TMSN₃ as an azide source. Such reactivity is conceptually similar to that of Rieske dioxygenases, capable of adding two cis-substituents to the C=C group in a syn-selective fashion. The bioinspired catalyst systems discussed herein provide facile access to a variety of enantiomerically enriched 1,2,3-trifunctionalized compounds, featuring both syn and anti 2,3-hydroxy azide moieties.

Although CeO₂/Co₃O₄ composites exhibit excellent catalytic performance in oxidation reactions, the atomic-scale origin of their interfacial interactions remains unclear. In this work, we compare two contrasting catalysts: Co₃O₄-supported Ce single atoms and Co₃O₄-supported CeO₂ nanoparticles. We reveal that these two forms of Ce promote catalytic performance through different mechanisms. Ce single atoms occupy the octahedral Co³⁺ sites within the Co₃O₄ structure, forming Ce³⁺-Vo-Co active sites and thereby induce local compressive strain and facilitate the formation of point-defective oxygen vacancies. More importantly, Ce³⁺ acts as an electron donor, elevating the d-band center of Co and facilitating O₂ activation via enhanced electron transfer to O₂ antibonding orbitals. In contrast, the extensive interfacial contact between CeO₂ nanoparticles and Co₃O₄ triggers ion migration, which subsequently generates defects or amorphous interfacial domains with high oxygen mobility. The configuration of interfacial defects is highly dependent on the size of CeO₂ nanoparticles. Catalytic tests for the liquid-phase aerobic oxidation of benzyl alcohol confirm the superior performance of the single-atom catalyst, which exhibits 1.5 times higher activity and a 27.7 kJ/mol lower activation energy than its CeO₂ nanoparticle counterpart. Our findings demonstrate that the interaction between Ce species and Co₃O₄ is dominated by electronic effects when Ce is atomically dispersed, whereas interfacial reconstruction becomes predominant with increasing CeO₂ nanoparticles size.

ABSTRACT: Implementing low-temperature catalytic methane combustion is imperative for curbing the release of greenhouse gases. However, this process is fundamentally limited by the high energy barrier for C-H bond activation and the slow migration of lattice oxygen species. In this work, we introduced a topology-directed defect engineering strategy to synthesize a series of Pd@Co₃O₄ nanocages with adjustable shell numbers by precisely controlling the pyrolysis kinetics of ZIF-67. Among the synthesized catalysts, the quadruple-shell 1%Pd@Co₃O₄-Q system exhibits the best catalytic performance (T₅₀ = 305 °C), marking a 2.8-fold enhancement in reaction rate relative to the pristine Co₃O₄-Q catalyst, along with outstanding stability. Results of multidimensional characterizations (electron paramagnetic resonance, O₂-temperature programmed desorption, X-ray photoelectron spectroscopy) confirm that the unique multi-shell topology not only induces a high density of surface oxygen vacancies, but also optimizes the electronic configuration of Pd through strong electron-metal-support interactions. Kinetic analysis and in-situ diffuse reflectance Fourier transform infrared spectroscopy experiments verify that the reaction proceeds via the Mars-van Krevelen mechanism. The Pd sites significantly lower the activation barrier associated with C-H bond rupturing during the rate-determining step (with E_a decreasing to 66.6 kJ·mol^-1), and the abundant oxygen vacancies boost the transport efficiency of lattice oxygen species. Furthermore, density functional theory calculations unveil that electron donation from Pd to Co₃O₄ weakens the Co-O bond, thereby simultaneously depressing the energy required for oxygen vacancy formation and the barrier for methane dissociation. This work not only introduces an efficient catalyst for methane combustion, but also proposes a universal mechanism for regulating the chemistry of surface defects through the topological structure of MOF derivatives.

Precise control of crystal growth allows for zeolites with tailored morphology, and one of the typical zeolite families is one-dimensional zeolites such as ZSM-23, which normally displays a needle-like morphology with micron-level length. This morphology not only strongly influences catalytic performances but also has potentially healthy issue. Herein, we for the first time show a successful synthesis of ZSM-23 zeolite nanosheets with a thickness of only about 10 nm from a novel gemini-type quaternary ammonium as an organic template. Characterizations of the samples demonstrate that ZSM-23 zeolite nanosheets along a and b axes have high crystallinity, large external surface area, and fully four-coordinated aluminum species. Very importantly, ZSM-23 zeolite nanosheets exhibit higher n-hexadecane (C₁₆) conversion and iso-C₁₆ yield in n-C₁₆ hydroisomerization than those of conventional ZSM-23 zeolite synthesized from N,N-dimethylformamide. These findings offer a favorable opportunity for the subsequent development of efficient zeolite catalysts in the future.

To replace scarce Rh resources and enhance the recyclability of the metal, we report a novel heterogeneous cobalt mononuclear complex catalyst, which possesses phosphorus-rich polymer backbone and P/S dual-atom coordination sites. This catalyst exhibited a much higher hydroformylation performance of 2,5-DHF compared to the Co-P homogeneous analogue, increasing conversion by 70% and shifting selectivity toward high-value-added 3-Formyl-THF by 15%. Under the optimal reaction conditions, the heterogeneous mononuclear complex Co₁/POPs-PPh₃-5P&2S catalyst displayed comparable performance of precious Rh-based catalysts, achieving a 96.8% conversion of 2,5-DHF and an 85.6% selectivity of 3-Formyl-THF for at least 5 runs. Comprehensive characterizations (extended X-ray absorption fine structure, X-ray photoelectron spectroscopy, in-situ Fourier transformed infrared, etc.) demonstrated that P/S dual-site coordination regulated the electronic structure of Co active centers. Notably, the incorporation of sulfur increased the difference in adsorption energy barriers between the substrate and its isomerized substrate, thereby promoting the massive generation of 3-Formyl-THF. Besides, time-of-flight secondary ion mass spectrometry and density functional theory calculations successfully evidenced the complete structure of the active center and established a coherent reaction mechanism. This study successfully developed a heterogeneous catalyst system based on a mononuclear cobalt complex，achieving a new strategy for non-noble metal catalysis and providing new insights into energy conservation and efficient resource utilization.