Catalytic conversion of CO₂ into valuable chemicals is a promising approach to mitigate the greenhouse effect and alleviate energy shortages. Hypercrosslinked polymers (HCPs) offer a scalable and stable platform for this conversion, but they often suffer from low CO₂ adsorption and activation capabilities, necessitating high temperatures and pressures for effectiveness. To overcome these limitations, nitrogen-based CO₂-philic active sites have been integrated into the structure of HCPs, enhancing CO₂ attraction and leading to superior adsorption performance. The incorporation of cobalt ions further bolsters CO₂ affinity, with HCP-PNTL-Co-B achieving the highest observed adsorption heat of 33.0 kJ·mol^-1 alongside a substantial 2.0 mmol·g^-1 CO₂ uptake. These modified HCPs exhibit higher yields and reaction rates in cycloaddition reactions with cocatalyst tetrabutylammonium bromide at room temperature and atmospheric pressure, while HCP-1,10-phenanthroline (PNTL)-Co-B demonstrates a higher CO production rate (2,173 μmol·g^-1·h^-1) and selectivity (84%) in photocatalytic reduction reaction. This research has successfully achieved outstanding carbon dioxide capture and conversion performance at room temperature and atmospheric pressure by introducing CO₂-philic active sites and cobalt ions into HCPs via facile one-step polymerization. This study provides a new method to design highly efficient organic catalysts for CO₂ conversion.

Aqueous zinc-ion hybrid supercapacitors (ZIHSCs) are highly favored for their abundant raw resources, friendly environment, high safety and unique electrochemical advantages. Nevertheless, their practical application is severely limited by the unsatisfactory zinc ion storage capacity of cathode materials. Herein, we constructed a N, O-enriched hierarchically porous carbon composed of ultrathin carbon nanosheets for ZIHSC cathode materials. Benefiting from the synergistic merits of unique structure, large specific surface area, abundant micro/mesopores, and high N and O content, the porous carbon electrodes demonstrate a substantial capacity of 287.2 mAh·g^-1 at 0.05 A·g^-1, accompanied by a maximal energy density of 86.5 Wh·kg^-1. Moreover, the assembled ZIHSCs present superior high-rate performance and impressive durability with capacity retention of 79.75% over 25,000 charge/discharge cycles. This strategy proposes a scalable approach to enhance the electrochemical energy storage capacity of ZIHSCs by coupling rapid ion adsorption and reversible redox reactions, which offers a new option for constructing low-cost cathode materials for desirable ZIHSCs.

The demands of the information era, driven by cloud computing and big data, necessitate high-density storage systems. In magnetic recording media, reducing bit size is crucial for significantly increasing areal density. Consequently, using single atoms as recording bits offers the potential to achieve unprecedented areal densities. However, achieving ferromagnetism in single atoms typically requires very low temperatures, and synthesizing large areas of single atoms for recording media remains a significant challenge. In this study, a straightforward mixing and stirring method was employed to intercalate a large number of Ni single-atoms into MoS₂ nanosheets. Remarkably, room-temperature ferromagnetism was observed in all samples. Specifically, the 2% Ni-doped MoS₂ exhibited a magnetic moment of 0.53 µ_B, which is close to the theoretical value. The magnetization depends on the bonding between nickel and sulfur atoms. In 2% Ni-doped MoS₂, nickel prefers to form Ni-S bonds, while at higher doping concentrations, S-Ni-S bonding is more prevalent, leading to antiferromagnetic coupling. The observed ferromagnetism in these higher-concentration-doped samples may be attributed to strain in the nanosheets induced by nickel intercalation or nanostructured NiS particles.

Photocatalysis plays an increasingly important role in the field of water treatment. Among the catalysts, Ag nanoparticles (NPs), a type of noble metal NP, show extraordinary potential for photocatalysis. Nevertheless, the aggregation caused by high surface energy limits their applications. The simple synthesis of Ag NPs with uniform size remains a challenge. In this work, a nitrogen-rich porous organic polymer (POP) with reduction ability, porous aromatic framework (PAF)-54, was chosen as the carrier for the in-situ synthesis of Ag NPs. By virtue of the reducing framework of PAF-54 and the formation of the AgCl/PAF-54 heterojunction, the in-situ reduction of Ag(I) was realized, and thus Ag NPs with the particle size of 20-25 nm were uniformly distributed on PAF-54, which exhibit a strong localized surface plasmon resonance (LSPR) effect. Furthermore, the Ag/AgCl/PAF-54 heterojunction effectively suppresses the recombination of photogenerated electrons and holes, leading to the enhanced photocatalytic ability of the composite material. Even with a small catalyst dosage, rapid tetracycline (TC) degradation can be achieved, and the degradation rate of TC reached 94.8% in 30 min. This study offers a facilitated approach for fabricating Ag-based POP composites with superior photocatalytic properties.

Utilizing selective photocatalysis conversion of amines represents an environmentally sustainable and economically feasible approach to generating valuable chemical products in the industry. Herein, carbon dots (CDs) incorporated in hydrochar (CDs/HCPP) were synthesized by one-pot hydrothermal carbonization of pomelo peel (PP) coupled with freeze-drying and used for aerobic oxidative coupling of benzylic amines. CDs were produced using only the pomelo peel as the carbon source, without the addition of any extra carbon additives. CDs/HCPP exhibited the greatest catalytic activity, achieving a benzylamine conversion rate of 99%, which was nearly 5.5 times of carbonized PP (CPP) without CDs and 1.14 times of CDs alone. Additionally, the oxidation of other amines, such as p-substituted benzylamines with groups that donate and withdraw electrons, was also demonstrated to be highly active and reusable using CDs/HCPP. This study has the potential to pave the way for novel methodologies and insights into synthesizing biomass composites adorned with CDs, enhancing the efficacy of photocatalytic syntheses.

Using supramolecular strategies to improve the generation of reactive oxygen species is a practical and environmentally friendly method, but it is also a difficult undertaking. In this study, we created and produced a vinylpyridine-modified tetraphenylethylene derivative TPE-Py-I, which has excellent solubility in water and has the ability to construct supramolecular dimers (2TPE-Py-I@CB[8]) in an aqueous solution through host-guest interaction with cucurbit[8]uril (CB[8]). The supramolecular dimer demonstrated a remarkable aggregation-induced emission response, with the fluorescence progressively intensifying upon the introduction of CB[8]. Meanwhile, the formation of supramolecular dimer also greatly improved the intersystem crossing effect of the molecular assembly system, so that the generation ability of reactive oxygen species including singlet oxygen (¹O₂) and superoxide anion radical (O₂^•-) were enhanced, which provided a basis for its application as an excellent supramolecular photosensitizer in photocatalytic organic reactions. To our delight, 2TPE-Py-I@CB[8] exhibits excellent photocatalytic properties, making it suitable for both phosphine photooxidation and cross-dehydrogenative coupling reactions. This work provides a non-covalent strategy for the development of supramolecular dimer photosensitizers and broadens its application in the field of photocatalytic organic conversion.

The ZSM-12 zeolite has attracted attention as the promising acid component of bifunctional catalysts for the n-alkane hydroisomerization because of its large size of micropore openings (0.57 nm × 0.61 nm) with 12-membered-ring and one-dimensional channels. However, the larger crystal size and stronger Brønsted acid strength of microsized ZSM-12 zeolite will lead to cracking of iso-olefin intermediates and decrease the iso-alkane yield. In this study, ZSM-12 zeolite samples partially and completely isomorphously substituted with gallium ([Ga,Al]Z12 and GaZ12) were in situ synthesized. The characteristic results indicate that isomorphous substitution by Ga can effectively reduce the crystal size to increase the mesoporosity and weaken the Brønsted acidity of the [Ga,Al]Z12 and GaZ12 samples. In addition, bifunctional catalysts with more appropriate metal-acid proximity for n-hexadecane hydroisomerization were prepared by mixing the 0.6Pd/A sample with 0.6 wt.% Pd loaded on γ-Al₂O₃ and the ZSM-12, [Ga,Al]Z12 and GaZ12 samples, respectively. The 0.3Pd/A-[Ga,Al]Z12 and 0.3Pd/A-GaZ12 catalysts both promote the maximum iso-hexadecane yield and distribution of multi-branched iso-hexadecane products due to their enhanced mesoporosity, reduced Brønsted acid strength, increased C_Pd/C_H+ ratios and improved metal-acid balance. Especially for the 0.3Pd/A-GaZ12 catalyst, when the n-hexadecane conversion is 93.5%, the maximum iso-hexadecane yield reaches 80.6%, and the proportion of multi-branched iso-hexadecane products is 64.6%, which are both the highest among all investigated catalysts. Accordingly, Ga isomorphous substitution is an effective strategy to develop the efficient bifunctional catalysts for hydroisomerization.

Noble metals such as iridium with high Tammann temperature are inclined to sintering resistance and may be promising in the high-temperature dry reforming of methane (DRM) process, yet the low atom utilization remains intractable. Herein, we synthesized Ir/TiO₂ catalysts via the conventional incipient wetness impregnation method and further downsized the Ir species from a nanoparticulate to a single-atom scale by gradually decreasing Ir loadings from 1.0 wt.% to 0.01 wt.%. With the advantage of single atoms for maximized atom utilization, Ir single atoms were employed to enhance atom utilization in the DRM process. Various characterizations, such as aberration-corrected high-angle annular dark-field scanning transmission electron microscopy, CO adsorbed in situ diffuse reflectance infrared Fourier transform spectra and X-ray absorption spectra demonstrated the existence of Ir single atoms in 0.01% and 0.05% Ir/TiO₂. During the DRM process, Ir single-atom catalysts exhibited a better specific reaction rate of as high as 697.71 mol_CH4·g_Ir^-1·h^-1 at 750 °C compared with that over Ir nanoparticles of mere 447.12 mol_CH4·g_Ir^-1·h^-1, which unambiguously showed the remarkable Ir atom utilization over Ir single atoms. Besides, the Ir single-atom catalysts also exhibited excellent stability during the DRM process for 50 h and revealed outstanding anti-coking and good sintering-resistance properties examined by the thermal gravimetric analysis-mass spectrometer and Raman spectroscopy. The strategy of employing Ir single atoms for the maximum atom utilization in the high-temperature reaction process can pave the way for better exploitation of noble metals in other industrial reaction processes.

The preparation of high-value 2,5-furandicarboxylic acid (FDCA) from biomass-based platform compound 5-hydroxymethylfurfural (HMF) is an important synthetic reaction, as the resulting FDCA holds promise to replace terephthalic acid to produce environmentally friendly polyester materials. However, due to the complex tandem nature of the oxidation of HMF to FDCA, which involves several stable intermediates, efficient conversion of HMF and achieving a high FDCA yield remain challenging. Herein, a catalyst of Co SAs/NPs@N-CNTs comprising Co single atoms (Co SAs) alongside Co nanoparticles (Co NPs) supported on carbon nanotubes (CNTs) was synthesized. Co SAs/NPs@N-CNTs exhibited outstanding catalytic activity for the selective oxidation of HMF to FDCA, achieving 100% HMF conversion and 94.2% FDCA yield. This remarkable performance was attributed to the synergistic effect between Co SAs and Co NPs. Poisoning and acid treatment experiments indicated that Co SAs served as the active sites, while Co NPs did not directly act as active sites. Instead, Co NPs merely assisted the Co SAs on the sidelines, facilitating the efficient conversion of HMF into various intermediates and promoting the further conversion of these intermediates into FDCA, thereby achieving high FDCA productivity. This strategy offers new insights for designing efficient catalysts for complex tandem reactions.

Compared to bulk solvents, reactions in the confined spaces of supramolecular self-assemblies feature rate acceleration, high efficiency and substrate selectivity. These advantages lead to efficient catalytic efficiency and excellent selectivity in enantioselective supramolecular photochemical transformations. During the last few years, enantioselective supramolecular photocatalysis has developed into one of the most powerful strategies to construct enantioenriched chiral compounds. In this review, the recent advances of enantioselective photochemical reactions taking place within the confined spaces of supramolecular assemblies are summarized, with an emphasis on the specific catalytic modes and chemical transformations. Organization of the data follows a subdivision according to supramolecular host and reaction type. At last, the current limitations and the future research orientation of this research field are discussed.

We designed a new approach to oxidize methane, a potent greenhouse gas. In this approach, the synergistic effect of photocatalytic ozonation is utilized to oxidize methane at low concentrations. Using ZnO nanomaterials modified with noble metals (i.e., Au, Pt, and Pd), results show that the catalytic oxidation of methane is generally significantly improved by the synergistic system approach. More specifically, the efficiency of photocatalytic ozonation was at least two times higher than the sum of the contributions from individual sub-processes (i.e., photocatalysis, catalytic ozonation, and ozone photolysis), and the synergistic effect was effectively utilized. The durability of the catalysts is another highlight, with no decrease in activity over ten cycles. Based on the experimental results, combined with the characterization, and taking Au/ZnO as an example, it can be seen that Au/ZnO with high specific surface area and high adsorption capacity is more conducive to ozone adsorption and activation, enhances the formation of active radicals (·O₂^- and ¹O₂) and promotes the synergistic effect. Meanwhile, we believe that the larger Au nanoclusters and the zero-valent stabilized Au are important reasons for the durability of the catalyst. This work provides a novel approach to removing low-concentration methane and guides further development of a practical photocatalytic ozonation system.

The catalytic performance of heterogeneous catalysts remains a great challenge for large-scale commercial applications under harsh reaction conditions. Herein, we designed a CuNiAl catalyst using a layered double hydroxides precursor, and the catalytic performances were evaluated in transfer hydrogenation of levulinic acid to γ-valerolactone with formic acid as a hydrogen donor. CuNiAl catalyst presented high activity and the improved stability compared to CuAl catalyst. The CuNi alloy formed in the CuNiAl catalyst could prevent Cu particles from partial oxidation, overgrowth and leaching under acidic reaction conditions. Moreover, the synergistic effects between Cu active sites and the surface acid-base on the surface were the key factors for producing γ-valerolactone with a high yield of 97.3% over the CuNiAl catalyst.

The conversion performance for electrocatalytic CO₂ reduction reaction (CO₂RR) relies on the affinity of CO₂ molecules. Ionic covalent organic frameworks (COFs) are promising platforms for CO₂RR due to the accessible catalytic sites in the skeleton, high CO₂ combination ability and the electronic conductivity. However, most ionic COFs are constructed via pre-functionalization of the monomers or post-modification of the skeleton, encountering incomplete loading or uneven distribution of the active sites. In this work, a cationic porphyrin-based COF using the (3-carboxypropyl)trimethylammonium and Co-porphyrin units is developed through the sub-stoichiometric bottom-up synthesis method to fine-tune the pore environment for modulating the binding ability of CO₂. Compared to base COFs, the cationic COFs exhibit improved electronic conductivity, high CO₂ adsorption uptakes and enhanced reducibility, further improving the electrocatalytic CO₂RR performance. Notably, the cationic COF achieves a high CO selectivity of 93% and a partial current density of 24.6 mA·cm^-2. This work not only offers considerable insights for improving the catalytic performance of COFs through the cationic groups but also provides a stoichiometry method to modulate the pore environment.

Electrochemical biomass upgrading is a promising substitute for oxygen evolution reaction (OER) to generate valuable chemicals in conjunction with hydrogen generation. Pursuing highly efficient and durable electrocatalysts for significant concentration levels (≥ 50 mM) of biomass electrooxidation remains an enduring challenge. Herein, we introduce a robust Cu-supported CoFe Prussian blue analogue (CoFe PBA/CF) electrocatalyst, adept at facilitating high-concentration (50 mM) 5-hydroxymethylfurfural (HMF) oxidation into 2,5-furandicarboxylic acid (FDCA), achieving an exceptional HMF conversion (100%) with a notable FDCA yield of 98.4%. The influence of copper substrate and adsorption energy are therefore discussed. Impressively, the CoFe PBA/CF electrode sustains considerable durability in a continuous-flow electrochemical reactor designed for consecutive FDCA production, showcasing FDCA yields of 100/94% at flow rates of 0.4/0.8 mL·min^-1 over 60 h’ uninterrupted electrolysis. This work provides a promising strategy to develop highly efficient and robust electrocatalysts for the consecutive production of high-value products coupled with green H₂ production.

Propane dehydrogenation (PDH) Pt-based catalysts are facing the serious challenge of coke deactivation. The locations would greatly influence the coke formation, while the detailed mechanism is not fully explored. Herein, the coke mechanisms on different locations including Al₂O₃, Sn, Pt, and Pt-Sn sites were deeply investigated via in situ Fourier transform infrared spectroscopy (FTIR) technology, and the key factors triggering catalyst coke deactivation were proposed. Excessive dehydrogenation of propyl species is a crucial initial step in the formation of coke, whether at metal sites or supports. These propyl species on Al₂O₃ supports then cyclize to form monocyclic aromatic and bicyclic aromatic species, while those on SnO_x sites cyclize to form monocyclic aromatic species. As for the Al₂O₃ supported PtSn catalysts, the strong dehydrogenation function and the interaction between Pt and Al₂O₃ supports trigger the complex coke formation mechanism. The surface Pt sites with saturated coordination are prone to coke deposition, leading to rapid deactivation at the initial stage of the reaction. However, the low-coordination Pt sites with ultra-small size are found to be highly resistant to coke formation in the PDH reaction, which selectively catalytic the PDH. Owing to the metal-support interaction, the extensive active hydrogen species generated from Pt can regulate the formation of coke precursors on the Al₂O₃ supports. Furthermore, the effect of hydrogen co-feed on coke deposition is also explored. The hydrogen co-feed inhibits the coke formation and results in a higher H/C ratio (3.96) for aromatic coke precursors. This study can enhance the understanding of the coke formation in PDH, which is important to designing efficient PDH Pt-based catalysts.

Against the backdrop of intensified urban heat island effect, adopting proactive personal thermal management (PTM) measures is crucial for maintaining health in modern societies. A hierarchical textile with optical design and fiber nanomanufacturing has been recently reported to show efficient radiative cooling ability in all-weather conditions and exhibit outstanding wearability. The above-mentioned study paves the way for its application in PTM in urban heat islands.

The conversion of toluene into high-value products without generating undesired CO₂ remains a critical challenge. Selective oxidation of toluene under visible light irradiation has emerged as a promising solution. This review offers a comprehensive interpretation of photocatalytic transformations in heterogeneous toluene oxidation. We start by outlining the basic mechanism of C–H bond activation of toluene and provide an overview of reactive oxygen species (ROS) within photocatalytic systems. Subsequently, we provide a summary of strategies that have been developed to enhance the conversion and selectivity of the heterogeneous photocatalytic system. Following this, advanced characterization techniques and density functional theory (DFT) calculations are discussed for understanding the structure-performance relationship of photocatalysts and the mechanisms underlying photocatalytic processes. Finally, we put forward a detailed discussion of current challenges and potential directions for future research, with the aim of offering valuable insights for this emerging field. We believe that this review will not only spark greater creativity in optimizing photocatalysts but also offer valuable insights for designing other C–H bond activation systems.

The light cycle oil (LCO) hydrocracking process converts polycyclic aromatics into highly valuable light aromatics such as benzene, toluene, xylene (BTX), in accordance with the requirements of low-carbon development and high-quality transformation from oil refining to chemical industry. The accessibility of acid sites is a critical factor that impacts LCO conversion and BTX yield. Initially, the fine structure and molecular size of the typical polycyclic aromatics in LCO and their hydrogenation reaction intermediates were investigated through gas chromatography-mass spectrometry (GC-MS) analysis and density functional theory (DFT) calculations. Three porous Y zeolites with comparable Si/Al molar atomic ratios and pyridine (Py)-measured Brønsted acid amounts were chosen as an acidic component to prepare NiMo/(Al₂O₃ + HY) catalysts. The acid accessibility of HY zeolite was characterized via dual-beam infrared spectroscopy using 2,4,6-tri-tert-butylpyridine (2,4,6-TTBPy) and trihexylamine (THA) as probe molecules, and the LCO hydrocracking performance was evaluated on a fixed-bed reactor. The results revealed that bicyclic aromatic hydrocarbons featuring multiple, short side chains such as dimethylnaphthalene and trimethylnaphthalene are the main components of LCO, with sizes larger than those of HY zeolite micropores. There is a strong positive correlation between LCO conversion and ring-opening rate of polycyclic aromatics and cycloalkanes in LCO. Among these three HY zeolite catalysts, the ring-opening rates of polycyclic aromatics and cycloalkanes, and the yields of C₆-C₁₂ aromatics and BTX increased in the order of HY1 < HY2 < HY3, which is consistent with external surface acidity measured by THA as the probe molecule.

Owing to its unique structure, porosity and photoresponse properties, two-dimensional hierarchically porous (2D-HP) C₃N₄ has attracted wide attention in environmental remediation and sustainable energy evolution fields. Up to today, 2D-HP C₃N₄ has been developed as an efficient photocatalyst for various environmental/energy photocatalytic applications. Its advantages in promoting light harvesting, reactant diffusion and transportation, surface molecule activation and photoinduced carrier separation have been verified. In this perspective, we highlighted the advantages of 2D-HP C₃N₄ in various photocatalytic reactions such as water splitting and H₂O₂ production. The relevant mechanism was simultaneously discussed. Moreover, the prospects and obstacles for the industrial utilization of 2D-HP C₃N₄-based photocatalysts are outlined and summarized. Finally, we envision available approaches for the deployment of 2D-HP C₃N₄-based materials to promote its practical application.