The hydrofunctionalizations of readily available alkenes and alkynes are one of the most effective and useful routes to afford diverse value-added compounds. Although traditional hydrofunctionalization strategies catalyzed by metal catalysts present convenient approaches, they are also accompanied by resource consumption and environmental crisis. Electrosynthesis, as a renewable and sustainable technology, has become a cost- and atom-efficient and useful synthetic route. In this review, the electrochemical-induced hydrofunctionalizations of alkenes and alkynes are summarized and presented. In each section, the electrochemical synthetic strategy to access hydrogenation and other hydrofunctionalization (hydroboration, hydrosilylation, hydroalkylation, hydroalkoxylation, hydrocyanation, hydrocarboxylation, etc.) products are elaborated in detail separately. Finally, the current challenges and prospects for electrochemical hydrofunctionalizations of unsaturated carbon‒carbon (C‒C) bonds are also discussed briefly.

Solid oxide cells (SOCs) are regarded as a promising energy technology due to their large current density, diverse range of fuels, and high energy conversion efficiency. The double perovskite Sr₂FeMoO₆ (SFM) has attracted considerable attention for SOCs due to its tunable structure with superior performance of high conductivity, excellent thermal stability, and remarkable carbon deposition resistance in a reducing atmosphere. However, the electrocatalytic activity of SFM is considerably lower than that of commercial Ni-based SOC electrodes. A timely summary of the synthesis, modulation, and application of SFM perovskites is of great significance for its further development for SOCs. In this review, the methods employed in the preparation of SFM electrocatalysts are introduced first. Then, the advancements in the application of different SFM-based electrocatalysts in the field of SOCs are reviewed, and the research progress in the in-situ exsolution of SFM-based electrocatalysts through ion regulation is assessed. Finally, the future issues associated with SFM-based electrocatalysts are addressed in the realm of electrocatalysis, to advance their application.

Covalent organic polymers (COPs), as emerging porous materials with well-defined architectures and high hydrothermal stability, have attracted extensive attention in the field of electrocatalysis. Herein, we report a rational design method for preparing oxygen reduction reaction electrocatalysts with the assistance of a predesigned macrocyclic COP model molecular. With the predesigned nitrogen position and structural features in macrocyclic chain-like COP-based materials, the obtained COP_MCT-Co-900 catalyst provided excellent oxygen reduction performance, where the half-wave potential (E_1/2) reaches 0.85 V (vs. RHE), comparable to commercial Pt/C. We also extended the strategy to similar macrocycle COPs and Fe-based and Ni-based metal sources and studied the oxygen reduction reaction performance of corresponding catalysts, proving the universality of the method. Interestingly, we assemble COP_MCT-Co-900 catalyst as air electrode catalyst of the self-made rechargeable zinc-air flow batteries, which exhibit outstanding power density (155.6 mW·cm^-2) and long cycle life (90 h, 270 cycles at 10 mA·cm^-2). Our studies provide a new method for the development of high-performance oxygen electrodes applied in zinc-air flow battery devices.

As the prevailing technology for energy storage, the extensive adoption of lithium-ion batteries (LIBs) inevitably results in the accumulation of numerous spent batteries at the end of their lifecycle. From the standpoints of environmental protection and resource sustainability, recycling emerges as an essential strategy to effectively manage end-of-life LIBs and reclaim valuable elements within them. Hydrometallurgy, closely intertwined with catalysis, stands as a relatively mature strategy for achieving high-value utilization of spent LIBs. In this review, our emphasis is placed on the interconnected themes of catalysis within the realm of hydrometallurgical recycling. Specifically, we delve into the crucial role that catalysis plays in both the recycling process of LIBs and the sustainable utilization of their extracted materials in various catalytic applications. This focused exploration aims to contribute insights into the intricate relationship between catalysis and the broader context of LIB recycling, shedding light on its pivotal role in achieving both environmental sustainability and functional material repurposing. Moreover, we highlight advanced characterization techniques, represented by surface-sensitive enhanced Raman spectroscopy, to fundamentally understand the reaction mechanism of catalysts, which, in turn, would inform more rational catalyst designs.

Highly selective synthesis of renewable methyl acrylate from bio-sourced formaldehyde and methyl acetate through one-step aldol condensation was successfully realized on Cu-modified nitrogen-containing Beta (NBeta) catalysts. Silicon-29 magic angle spinning nuclear magnetic resonance (²⁹Si MAS NMR), Fourier transform infrared spectroscopy (FT-IR), temperature-programmed desorption of ammonia, temperature-programmed desorption of carbon dioxide, and element analysis indicate that nitridation weakens the acid strength, reduces the number of acidic sites and introduces basic sites through the formation of Si−N bond on Beta zeolites, thereby promoting methyl acrylate selectivity and reducing the coke formation. Adding Cu into NBeta further finely tunes the basicity and acidity balance and thus inhibits the by-product acetone. High methyl acrylate selectivity of 95% and formaldehyde conversion of 99% were achieved over Cu/NBeta catalyst under optimized conditions. The coke content decreases remarkably from 28% on H-form Beta (HBeta) zeolites to 17% on NBeta zeolites doped with Cu due to its appropriate basicity/acidity. Cu/NBeta has good regeneration capability, and the weakening of Si-N species may account for the decline of catalytic performance after successive regeneration. The catalytic performance was restored when the regenerated catalyst was nitridated again.

The hydrogen form of low-silica KFI zeolite, with a Si/Al ratio of 3.2 (referred to as H-KFI-3.2), has been shown to possess significant selectivity for monomethylamine (MMA) and dimethylamine (DMA) in methanol amination reactions. However, its industrial viability for MMA and DMA synthesis has been hindered by its relatively low methanol (MeOH) conversion and yield of MMA plus DMA. In this study, we synthesize high-silica KFI zeolite with an elevated framework Si/Al ratio of 5.4 (designated as KFI-5.4) using a novel K⁺ and 18-crown-6 complex [referred to as (K⁺)CCH, with a ratio of 18-crown-6 to K⁺ of 2.85] as an organic structure-directing agent. Control experiments have demonstrated that the presence of both K⁺ and OH^- ions is essential for the formation of KFI-5.4 zeolite. The hydrogen form of KFI-5.4 (H-KFI-5.4) exhibits significantly enhanced MeOH conversion (95.2%) and yield (75.1%) of MMA plus DMA compared to the low-silica H-KFI-3.2 under similar reaction conditions. This represents the highest level of catalytic performance among reported small-pore zeolites to date. Furthermore, the yield and selectivity of MMA plus DMA can be further improved by modifying KFI-5.4 with an appropriate loading of Na⁺, which suppresses the formation of the by-product dimethyl ether. This study introduces a new high-silica KFI zeolite catalyst with exceptional MeOH conversion and yield for the production of MMA plus DMA.

The low performance of electrode materials is the main obstacle limiting the development of the supercapacitor industry, which can be solved by doping cobalt ferrate nanoparticles (NPs) with carbon materials. Herein, the composites of CoFe₂O₄ based on activated carbon (AC) were successfully prepared using a one-step solvothermal method and subsequently applied in anodes of battery-type asymmetrical supercapacitors. The effect of solvothermal temperature and heating time on the composite characteristic was systematically evaluated. The electrochemical analysis in the three-electrode system revealed that modified activated carbon heated at 140 °C for 24 h (140MAC24) displayed excellent specific capacitance of 571.36 F/g at the current density of 0.2 A/g due to the synergistic effect of the double-layer and faradic capacitance. Moreover, iron and cobalt elements in CoFe₂O₄ could change into the oxide form to accelerate charge in potential range window of -1.0 to -0.2 V and discharge from -0.2 to 0.2 V, respectively. Meanwhile, the result of assessing economic feasibility suggested the splendid availability of 140MAC24 electrodes. Additionally, the assembled supercapacitor displayed the outstanding specific capacitance of 171.31 F/g in the potential window of 1.8 V, energy density of 43.5 Wh/kg at the current density of 0.2 A/g, and capacitance retention rate of 82.49% after 10,000 cycles. The excellent electrochemical properties demonstrated that CoFe₂O₄ could be used as a bifunctional agent for enhancing supercapacitive performance.

Graphene oxide (GO) membranes hold significant promise for the water purification. However, they also face the problem of structural swelling, which limits their use in water treatment applications. In this work, a novel dual-modulated core-shell metal-organic framework@Chitosan (MOF@CS) was successfully synthesized and used as an intercalation cross-linker to optimize the interlayer spacing and stability of GO membranes. Molecular dynamics simulation confirms that MOF@CS, acting as an intercalator, accelerates the water diffusion rate within the channels of the GO layer compared to a pure GO layer. At the same time, Fourier Transform Infrared Spectroscopy analysis reveals that MOF@CS serves as a cross-linker for covalently cross-linking the GO layer. The nanofiltration performance and stability of the improved MOF@CS-GO composite membranes were significantly enhanced. Compared to the pure GO membranes, the MOF@CS-GO composite membranes exhibited enhanced Congo red rejection rates (from 76.5% to 95.6%) while maintaining a high pure water flux (34.5 L·m^-2·h^-1·bar^-1) and good structural stability (stable dye removal performance over 120 h). This dual regulation strategy is expected to effectively solve the swelling problem of GO membranes in aqueous media and open up avenues for advancing their performance.

The chemical upcycling method is a promising strategy to alleviate the pollution problem of waste plastics by tapping into their intrinsic value and converting them into high value-added products. Zeolite-based catalysts are one of the surprising and efficient classes of thermocatalytic materials that have recently attracted considerable attention for waste plastic upcycling. They are designed for targeted applications with a wide range of adjustable acidic sites, multiple pore structures, and synergistic interactions with surface metals. In this review, we categorize plastics being converted into different high-value products and introduce the role of zeolite-based catalysts in the thermal upcycling of plastics. The structure-performance relationships of zeolite-based catalysts in catalytic reactions are discussed in depth. Finally, the future development of these multifunctional catalysts applied to the upcycling of plastics is outlined.

The investigation of organic cage-based frameworks (OCFs) has attracted increasing attention over the past decade due to their versatile synthetic methods and broad property range resulting from the unique combination of porous organic cages (POCs) with diverse framework materials, including porous organic polymers (POPs), metal-organic frameworks (MOFs), and supramolecular organic frameworks (SOFs). Nevertheless, a comprehensive summary of the research advancements in OCFs remains elusive in the literature. This review addresses this gap by providing a detailed overview of the development of OCF-based materials from both synthetic and applicative perspectives. The discussion begins with systematically exploring design principles and common strategies for elaborating OCFs, achieved by rational selection of bond-forming routes suitable for various POC monomers, including covalent bonds, coordination bonds, and supramolecular interactions. Subsequently, the review highlights the functional attributes derived from the distinctive structural features of OCFs, showcasing their task-specific applications in adsorption/separation, catalysis, membrane technology, and other fields. Lastly, the article summarizes the opportunities and challenges anticipated as the exploration of the OCF family continues to advance in material science.

ZSM-11 zeolite is a promising catalyst for methanol to olefins (MTO); however, its low catalytic stability limits its realistic application. Herein, various ZSM-11 zeolites with different particle sizes were synthesized. The particle size of ZSM-11 has a significant influence on the formation and evolution of reaction intermediates, thereby determining its catalytic performance in MTO. Notably, S-ZSM-11, with a smaller particle size (approximately 400 nm), showed remarkable propene selectivity and catalytic lifetime as high as 42.6% and 243 h, respectively. These values were significantly higher than those observed with larger particle sizes (> 1 µm). The results obtained from gas chromatograph (GC)-MS, ¹³C MAS NMR, and various isotope-labeling experiments indicated that reduction of crystal size, accompanied by the generation of more intracrystalline mesopores, inhibits the aromatic intermediates formation and decreases the aromatic-based cycle contribution. In contrast, the alkene-based cycle is relatively enhanced, resulting in higher yields of propene and C₃₊ alkenes. Moreover, ethene is mainly produced via the paring route due to the limitation of alkyl side-chain growth of methylbenzenes.Highlights: various ZSM-11 zeolites with different particle sizes were synthesized by the hydrothermal method. S-ZSM-11, with a particle size of approximately 400 nm, shows superior catalytic performance in methanol to olefins. The propene selectivity and catalytic lifetime reach as high as 42.6% and 243 h, respectively. Decrease of crystal size inhibits the formation of aromatic species and decreases the aromatic-based cycle contribution. Ethene is mainly produced via the paring route.

Crystalline porous organic salts (CPOSs) are an emerging class of promising materials with intrinsic highly polar nanoconfined microporosity. However, their single microporous structure greatly hinders their development in the field of catalysis and adsorption. Constructing a hierarchical porous structure can effectively reduce the mass transport resistance, thus expanding the scope of their applications. Herein, we report the synthesis of a three-dimensional (3D) ordered macro-/microporous hierarchical CPOS (HCPOS-1) using a template-assisted approach for the first time. The as-synthesized HCPOS-1 prepared from a polystyrene colloidal crystal template showcases a 3D ordered macroporous structure while also preserving the microporous structure. The 3D ordered macroporous structure in such a hierarchical structure, together with its hydrophilic surface, endows HCPOS-1 with the ability to immobilize large-sized enzymes through physical adsorption under mild conditions. The resulting catalase/HCPOS-1 showcases a high enzyme immobilization capacity and avoids undesired conformational changes of enzymes during the immobilization process, thus exhibiting excellent catalytic activity for the decomposition of hydrogen peroxide.

Chiral chemistry is often regarded as the science of studying the stereostructure and symmetry of organic molecules. It mainly focuses on the presence of chiral centers in specific structures and their impact on conformation, properties, and functions. In this field, researchers explore the special properties and potential applications of chiral compounds through synthesis, separation, and characterization. Here, we aim to provide a detailed overview of diverse functionalized cages based on chiral skeletons and their applications in enantioselective recognition and separation, and a diversity of chiral caged skeletons bearing customized functionalities conducted on the recognition and separation of chiral guests.

Although cationic porous polymers have been widely used for gene and drug delivery, the delivering function of anionic porous polymers has rarely been explored. Herein, we prepare a polyanionic flexible organic framework (pa-FOF) through the quantitative formation of the acylhydrazone bond from a tetraanionic tetraaldehyde and a tetraanionic diacylhydrazine. Pa-FOF is highly water-soluble and has a size of 26 to 51 nm, which depends on the concentration of the monomers, and an aperture of approximately 3.8 nm. Fluorescence, zeta potential, confocal laser scanning microscopic and flow cytometric experiments reveal that pa-FOF can adsorb basic proteins, including lysozyme, trypsin and cytochrome c, which is driven by intermolecular ion-pairing electrostatic attraction and hydrophobicity, and realizes efficient intracellular delivery of the adsorbed proteins. Confocal laser scanning microscopic imaging experiments further illustrate that the delivery of cytochrome c can significantly increase its ability of causing cell apoptosis.