Chemical depolymerisation of poly(ethylene terephthalate)(PET) is a widely explored method to recycle plastic waste, with particular benefits on waste streams unsuitable for mechanical recycling. Glycolysis, the employment of ethylene glycol (EG) and a catalyst to effect depolymerisation, is a promising technology. Herein, we report the use of 1,8-bis(dimethylamino)naphthalene, commonly known as a proton sponge (PS), as an effective, novel organocatalyst for PET glycolysis. Use of PS enables an 89% bis(2-hydroxyethyl)terephthalate (BHET) yield after only 45 min at 180 °C using 10 equiv. EG and 20 mol% catalyst. The aromaticity of PS allows for a shortened induction time by improving PET swelling compared to comparably basic non-aromatic catalysts such as tributylamine and pempidine. PS glycolysis obeyed pseudo first-order kinetics (R2 > 0.98) with an apparent activation energy of 126.3 kJ mol−1. Depolymerisation catalysed by PS is shown to be tolerant of air and a reduced catalyst loading of 5 mol%, and was demonstrated at 10 g scale, giving a 64% BHET isolated yield (>99% purity). A range of aromatic amines, structurally related to PS, were synthesised and investigated to provide a deeper understanding and mechanistic insights into the reactivity of this class of amine catalyst.

Rice husk biomass was investigated under O2/CO2 oxy-fuel conditions using Thermogravimetric analysis (TG)-derivative thermogravimetry (DTG)-mass spectrometry (MS) experiments, iso-conversional kinetic analysis, and ReaxFF reactive molecular dynamics simulations. Oxy-fuel combustion significantly enhanced combustion performance compared with air combustion. At 10 °C·min−1, the ignition and burnout temperatures decreased to 235 °C and 435 °C under 70%O2/30%CO2, while the maximum mass loss rate increased more than fivefold and the comprehensive combustion index increased markedly. Online MS analysis showed concentrated CO2 formation and O2 consumption within 280–330 °C, accompanied by markedly suppressed NOx and SO2 emissions. Kinetic analysis revealed high apparent activation energies (525–548 kJ·mol−1) at α ≈ 0.5; these values are conversion-dependent and sensitive to the iso-conversional method employed and therefore reflect relative kinetic trends rather than intrinsic Arrhenius parameters, indicating a transition from chemical control to diffusion–structure-coupled control. Molecular dynamics simulations further confirmed that moderate oxygen enrichment promotes organic backbone cleavage, whereas excessive oxygen leads to a carbon-limited regime. These results provide mechanistic insights into biomass oxy-fuel combustion and its optimization for CO2 capture applications.

ABSTRACT Catalytic dehydrogenation of decahydroquinoline (DHQ) to quinoline is a promising pathway for hydrogen release in liquid organic hydrogen carrier systems. In this work, solvent‐free DHQ dehydrogenation over Pd/Al 2 O 3 is systematically investigated to evaluate hydrogen release performance and reaction kinetics. High DHQ conversion (83.9%) and degree of dehydrogenation (82.7%) are achieved at optimal reaction conditions. A power‐law kinetic model based on a simplified reaction mechanism is developed and simulated using a Markov Chain Monte Carlo (MCMC) approach for estimation of rate constants and validation of concentration profiles with experimental data. The apparent activation energies are determined to be 45.85 kJ/mol for DHQ to 5,6,7,8‐tetrahydroquinoline (bz‐THQ) and 185.43 kJ/mol for bz‐THQ to quinoline formation, identifying latter as the rate‐limiting step. This framework provides mechanistic insight and supports the potential of DHQ as an efficient hydrogen carrier.

Studies on low-temperature degradation for sulfur hexafluoride over sulfidated nanoscale zero-valent iron supported on zeolite ZSM-5: heterostructures, interfacial activation and fluorine migration.

Unraveling synergistic control in green Leaching: A double exponential kinetic model for efficient and sustainable indium recovery from E-waste using deep eutectic solvents.

Tailoring Cu-CeO₂ catalysts to elucidate the morphology-activity relationship in low-temperature water-gas shift reaction.

ABSTRACT This study investigates the thermal curing behavior of allyl‐functionalized SMP‐10, a preceramic polymer used as a silicon carbide (SiC) precursor in ceramic matrix composites (CMCs). The relatively high curing temperature of SMP‐10 may pose a significant processing challenge, as it can impact quality, microstructure, and performance of the composite. However, the allyl group enables radical‐initiated crosslinking pathways. To address this, the effect of radical initiators, dicumyl peroxide (DCP) and Luperox 101, on lowering the curing temperature was examined. Using non‐isothermal differential scanning calorimetry (DSC) at heating rates of 0.5, 1, 2.5, 5, and 10/min, the behavior of pure SMP‐10 and systems with 2 wt.% initiator was monitored. Kinetic analysis was performed using Kissinger and Ozawa peak‐based methods, model‐free isoconversional methods (Kissinger–Akahira–Sunose [KAS], Flynn–Wall–Ozawa [FWO], and Starink) and model fitting method (Master plot). The results showed that the initiators significantly lower the onset curing temperature. However, the apparent activation energy () increases from approximately 116–122 kJ/mol for pure SMP‐10 to 141–153 kJ/mol for the system with DCP and 155–156 kJ/mol for the system with Luperox 101. To better understand this trend, transition state theory was applied. It was found that the acceleration is not driven by a reduction in the enthalpic barrier, but rather by a shift in the entropy of activation (), from negative values in the pure system (approximately J/) to large positive values with initiators (approximately 77 J/ for DCP and 85 J/ for Luperox). The results suggest that curing in the presence of initiators proceeds through a dissociative transition state that is entropically more favorable, leading to a lower Gibbs free energy of activation (). These findings provide a basis for developing more efficient low‐temperature curing strategies for advanced CMC processing.

Electronic interface interaction (EII) plays an important role in regulating the structure-function relationship of metal/oxide heterogeneous catalytic systems. In this work, we prepared Al2O3/Ag inverse oxide/metal catalysts with a facile synthetic method without using any organic ligand. The composites were supported by well-defined silver nanocubes (Ag NCs) and covered by an oxide layer with variable coverage as confirmed by transmission electron microscopy (TEM) and high-sensitivity low-energy ion scattering spectroscopy (HS-LEIS) characterizations. The catalytic performance toward the reduction of 4-nitrophenol (4-NP) in excess NaBH4 obviously enhanced with increasing coverage of alumina overlayer; the composite principally provided more surface adsorption sites for reactants, confirmed by the increasing saturated adsorption capacity toward 4-NP. In comparison with pristine Ag NCs and bulk Al2O3, optimized Al2O3/c-Ag showed superior catalytic performance with about complete conversion of 4-NP within 2 min, keeping high stability for six cycles; the reaction possessed lower apparent activation energy (35.0 kJ/mol), and the corresponding pseudo-first-order kinetic rate constant (2.11 min-1) was about 3.27 times greater than that of Ag NCs (0.65 min-1). In addition, X-ray photoelectron spectroscopy (XPS) characterization indicated that overall Ag 3d peaks shifted to lower binding energy with increasing percentage of oxide layer, indicating an inclination of metal-oxide interface electron transfer, and Ag NCs acted as a charge contributor, thus directly influencing the catalytic performance in such an electron inducing reaction. This report provides a profound understanding of the electronic interaction between metal and nonreducible oxides, helping to construct a more efficient and stable silver-based catalyst for catalytic reduction of aromatic nitro compounds.

Ultrasound-assisted extraction of flavonoids from Cercis chinensis flowers using deep eutectic solvents: optimization, characterization, kinetics and bioactivity☆

PtRu nanoparticle catalysts with adjustable electronic environments for efficient low-temperature dehydrogenation of cycloalkanes.

Abstract The speciation, inventory, and dynamic changes of water (OH/H 2 O) on the lunar surface remain poorly constrained. The Chang’e-6 (CE-6) mission conducted in situ spectroscopic measurements of lunar water over time intervals shorter than one lunar local hour (10:00–11:00 a.m.). By integrating spectral analysis with quantitative water content estimation, we provide compelling evidence for two distinct water reservoirs: adsorbed molecular water (H 2 O) on the surfaces of soil grains, and hydroxyl (OH) groups incorporated within the crystal lattices of minerals. The in situ observations further document the gradual loss of water molecules (up to 48 ppm) until near exhaustion over an hourly time scale on the lunar surface. For the first time, we calculated the apparent desorption activation energy ( E d = 1.23–1.26 eV) of water molecules based on in situ measurements, which is consistent with observations from the Lyman Alpha Mapping Project spectrometer and results from laboratory experiments. These water molecules are inferred to originate from solar wind proton (H + ) implantation, forming via recombinative desorption of chemically bound OH in lunar minerals and glasses. This study constitutes a significant advance toward elucidating lunar water dynamics and provides critical parameters for modeling the lunar water cycle.

ABSTRACT In this study, vulcanized phenyl silicone rubber was subjected to thermal oxidative aging at 180°C and 210°C. The mechanical properties, structural integrity of the main and side chains, thermal stability, and apparent activation energy of the samples before and after aging were characterized using a tensile testing machine, Fourier‐transform infrared (FTIR) spectrometer, and thermogravimetric analyzer (TGA). Mechanical testing revealed that, at 180°C, the elongation at break of phenyl silicone rubber decreased gradually with aging time, while the tensile strength initially increased and subsequently declined. In contrast, at 210°C, both the elongation at break and tensile strength exhibited a rapid decrease. FTIR analysis indicated that the observed changes in mechanical properties are primarily associated with the degradation of the polymer main chain. TGA analysis demonstrated that the thermal oxidative aging process proceeds through two distinct decomposition stages. Furthermore, the apparent activation energy ( Ea ) initially decreases with increasing conversion and then gradually increases, reflecting a shift in the dominant degradation mechanism from side‐chain oxidation to main‐chain scission.

To address the challenges of high hydrogen release temperatures, sluggish kinetics, and inadequate cycling performance of magnesium hydride (MgH2), we developed the niobium-based bimetallic compound catalyst CuNb2O6 with excellent catalytic performance. It was found that the MgH2/CuNb2O6 composite material achieved 4.28 wt % hydrogen uptake within 10 min at 100 °C, and even at a lower temperature of 50 °C, it has 2 wt % hydrogen absorption capacity within 60 min, showing excellent hydrogen absorption performance. For hydrogen desorption, the MgH2/CuNb2O6 composite material demonstrated exceptional midtemperature hydrogen release kinetics, with 4.65 wt % hydrogen released within 20 min at 225 °C. The apparent activation energy for hydrogen release of MgH2/CuNb2O6 was determined to be 50.95 kJ/mol, which was approximately 66.4% less than that of ball-milled magnesium hydride. Cyclic testing further confirmed the stability of the MgH2/CuNb2O6 composite, with its hydrogen storage capacity stabilizing at 5.21 wt % after 50 cycles. Catalytic mechanism studies revealed that the MgH2/CuNb2O6 composite undergoes in situ reconstruction of multiple-phase catalytically active species, which effectively improved the hydrogen storage performance of MgH2. This work innovatively constructed a representative Mg2Cu@NbO2 heterojunction, and the results showed that hydrogen molecules were significantly activated at the interface, demonstrating the synergistic catalytic effect between the Cu and Nb species. This study provides a possible approach for designing high-efficiency catalysts for magnesium-based hydrogen storage materials.

Fluorine-oxygen dual sites engineered on carbon enable high efficiency in the cycloaddition of carbon dioxide: synergistic effect, density functional theory validation and kinetic modeling.

Biodiesel, which is a blend of fatty acid methyl esters (FAME), has garnered significant attention as a promising alternative to petroleum-based diesel fuel. Nevertheless, the commercial production of biodiesel faces challenges due to the high costs associated with feedstock and the non-recyclable homogeneous catalyst system. To address these issues, a solid catalyst derived from construction industry waste cement was synthesized and utilized for biodiesel production from waste cooking oil (WCO). The catalyst’s surface and physical characteristics were analyzed through various techniques, including Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier Transform Infrared Spectroscopy (FTIR). The waste-cement catalyst demonstrated remarkable catalytic performance and reusability in the transesterification of WCO with methanol for biodiesel synthesis. A maximum biodiesel yield of 98.1% was obtained under the optimal reaction conditions of reaction temperature 65 °C; methanol/WCO molar ratio 16:1; calcined cement dosage 3 g; and reaction time 8 h. The apparent activation energy (Ea) from the reaction kinetic study is 35.78 KJ·mol−1, suggesting that the transesterification reaction is governed by kinetic control rather than diffusion. The biodiesel produced exhibited high-quality properties and can be utilized in existing diesel engines without any modifications. This research presents a scalable, environmentally benign pathway for WCO transesterification, thereby contributing significantly to the economic viability and long-term sustainability of the global biodiesel industry.

Spontaneous coal combustion accounts for more than 90% of mine fires, and at the same time, the ‘dual carbon’ strategy requires fire prevention and extinguishing materials to have both low-carbon and environmentally friendly functions. To meet on-site application needs, a composite gel with fast injection, flame retardant, and CO2 adsorption functions was developed. PVA-PEI-PAC materials were selected as the gel raw materials, and an orthogonal test with three factors and three levels was used to optimize the gelation time parameters to identify the optimal formulation. The microstructure of the gel, CO2 adsorption performance, as well as its inhibition rate of CO, a marker gas of coal spontaneous combustion, and its effect on activation energy were systematically characterized through SEM, isothermal/temperature-programmed/cyclic adsorption experiments, and temperature-programmed gas chromatography. The results show that the optimal gel formulation is 14% PVA, 7% PEI, and 5.5% PAC. The gel microstructure is continuous, dense, and rich in pores, with a CO2 adsorption capacity at 30 °C and atmospheric pressure of 0.86 cm3/g, maintaining over 76% efficiency after five cycles. Compared with raw coal, a 10% gel addition reduces CO release at 170 °C by 25.97%, and the temperature-programmed experiment shows an average CO inhibition rate of 25% throughout, with apparent activation energy increased by 14.96%. The gel prepared exhibited controllable gelation time, can deeply encapsulate coal, and can efficiently adsorb CO2, significantly raising the coal–oxygen reaction energy barrier, providing an integrated technical solution for mine fire prevention and extinguishing with both safety and carbon reduction functions.

The hydration reaction of cementitious materials in high-altitude and cold regions is affected by low temperatures. To study the hydration reaction of the ground granulated blast furnace slag (GGBS)-cement system in cold areas, the hydration heat of the GGBS-cement system at lower temperatures was studied via the isothermal calorimetry method. The results showed that GGBS promoted the hydration of C3S at both normal temperature (20 °C) and lower temperature (5–15 °C), and the GGBS led to the increase of heat flow of Portland cement per unit mass in the composite cementitious system. The apparent activation energy (Ea) result suggests that GGBS enhances the temperature sensitivity of the hydration process, which limits the substitution level of Portland cement by GGBS in cold areas. The nucleation rate of the pastes incorporating GGBS is higher than that of the pure cement paste at normal temperature and low temperature (20–5 °C). The effect of GGBS content on the growth rate of pastes at lower curing temperatures is smaller than that at normal temperature curing (20 °C).

Incorporating hydrophobic associations into hydrophilic networks as energy dissipation units is an efficient strategy to toughen hydrogels. However, the micro-segregated structures often lead to turbid hydrogels with poor optical properties. Here, we report the synthesis of transparent, tough, and fluorescent hydrogels in which tetraphenylethylene (TPE) fluorogens are linked to the network by a polymethylene spacer. The TPE motif and polymethylene spacer form hydrophobic associations, affording the transparent hydrogels with excellent mechanical properties and strong fluorescence. The mechanical properties of the hydrogels can be tuned by the fraction of hydrophobic units, the length of the polymethylene spacer, and the presence of the TPE motif. A rubbery-to-glassy transition is found in poly(12-(4-(1,2,2-triphenylvinyl)phenoxy)dodecyl acrylate-co-acrylic acid) hydrogels and poly(4-(1,2,2-triphenylvinyl)phenoxy)hexyl acrylate-co-acrylic acid) hydrogels as the fraction of hydrophobic units increases. The increased glass transition temperatures and apparent activation energies of the hydrogels with longer spacers and the TPE motif indicate a synergistic effect between the hydrophobic polymethylene and TPE motifs. Small- and wide-angle X-ray scattering results show that these tough and fluorescent hydrogels have compact hydrophobic domains with a quasi-lamellar structure. The hydrophobic domains are disrupted during stretching to dissipate energy, accounting for the high toughness of the hydrogels. This study presents a novel strategy to construct tough and fluorescent hydrogels by forming synergistic associations, which should be informative for designing other tough materials with specific functions and applications.

ABSTRACT How to break the trade‐off effect between oxidability and SO 2 resistance through regulating the electron density of active sites during industrial volatile organic compounds (VOCs) decomposition is a huge challenge. Herein, the Pt 1 electron density was optimized by modulating the electrostatic adsorption ability of MnO 2 or Al 2 O 3 with different structural characteristics. A synergistic Pt 1(0.2) ‐[Pt 1(0.8) /MnO 2 ]/Al 2 O 3 island‐sea catalyst converts 90% of acetone to CO 2 at just 160°C in the presence of 30 ppm SO 2 (apparent activation energy as low as 81.06 kJ·mol −1 ), and displays high universality to other pollutants such as propane and toluene. Pt 1 atoms stabilized on MnO 2 island are mostly positively charged (Pt δ+ ), which dominate in adsorbing and activating acetone molecules with high electronegativity. The strong interaction between Pt and MnO 2 can promote the cleavage of C‐C and accelerate the generation of active *O species. Meanwhile, Pt 1 atoms on Al 2 O 3 are proposed in metallic state (Pt 0 ) to preferentially adsorb SO 2 , producing inactive and easily decomposable SO 4 2− /SO 3 2− species, therefore protecting the Pt δ+ active sites. This work provides new ideas for developing specific catalysts with synergistic functionalities for efficacious catalytic purification of VOCs in industrial complex environments, displaying remarkable practicability and environmental significance.

Abstract This study investigates the crystallization kinetics and Fe doping effects Ni50-xMn₃₉Sn₁₁Fex(x=0 、 0.5 、 2 、 4at.%)n alloy thin films. The amorphous films were prepared by DC magnetron sputtering, and their structural characteristics were confirmed by SEM and XRD analyses. Differential scanning calorimetry (DSC) results show that the crystallization peak temperature increases from 542.7 K to 568.0 K with increasing Fe content, accompanied by a rise in apparent activation energy, indicating an enhanced crystallization difficulty. The crystallization process exhibits typical volumetric characteristics with an average Avrami exponent of approximately 1.2, suggesting a diffusion-controlled growth mechanism transitioning from one-dimensional to three-dimensional. Local activation energy analysis further reveals variations in crystallization behavior under different Fe doping levels. These findings provide theoretical guidance for optimizing the heat treatment and performance of Ni-Mn-Sn-based alloy thin films.