Persulfate-based advanced oxidation processes (PS-AOPs) combined with visible-light photocatalysis offer a sustainable solution for water purification, although achieving exceptional efficiency remains challenging. In this study, a pyridine-embedded carbon nitride photocatalyst (MPY-CN) was synthesized via a simple thermal copolymerization of melamine (MA) and 2,4-diamino-6-(2′-pyridinyl) -triazine (PTZDA). The as-prepared MPY-CN enables efficient PMS activation for pollutant degradation under visible light. Under optimized conditions, the MPY-CN/PMS system demonstrates significantly enhanced degradation efficiency within just 20 min at a low PMS dosage (0.163 mM), achieving a reaction rate constant of 0.172 min−1, which is six times that of individual M-CN and PY-CN systems. Multiple characterization techniques and theoretical calculations confirm that the introduction of the pyridine ring (Py) optimizes the electronic structure, enhances carrier separation, and significantly improves photocatalytic performance. Mechanistic research suggests 1O2 is primary active species. Finally, a life cycle assessment (LCA) indicates that MPY-CN, a green, low-carbon and environmentally friendly photocatalyst, offers a sustainable solution. This study provides a reformatory tactic for crafting highly valid metal-free photocatalytic PMS activation systems.

High-density aviation fuels and diesel-range cycloalkanes are in high demand for the transportation sector, but the development of sustainable and high-efficiency synthesis routes from biomass-derived platform chemicals remains a key challenge. High-density aviation fuel and diesel-grade cycloalkanes were successfully synthesized from biomass-derived isophorone and furfural through a continuous process of selective hydrogenation, aldol condensation, and hydrodeoxygenation reaction. (E) 2-(Furan-2-methylene)-3,5,5-trimethylcyclohex-1-one (1A) was obtained by selective hydrogenation of isophorone to obtain 3,3,5-trimethylcyclohexanone (TMCH), which was then subjected to aldol condensation with furfural. The system studied key reaction parameters such as solvent type, temperature, catalyst type, catalyst loading, and reaction time that affect the aldol condensation of TMCH and furfural. The yield of 1A reached 98.69%, under optimized conditions using NaOH as the catalyst at a molar ratio of 3,3,5-trimethylcyclohexanone:furfural = 1:1, NaOH 0.15 g, anhydrous ethanol as the solvent, and a reaction temperature of 313 K for 1 h. A series of nickel-based catalysts supported on porous materials, including SiO2, CeO2, Al2O3, H beta, and HZSM-5, were prepared and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). These catalysts were evaluated for the hydrodeoxygenation of 1A. Among them, the 10% Ni-SiO2 catalyst exhibited the highest catalytic activity, affording a C9-C14 cycloalkane yield of 88.32% and a total carbon yield of 99.6%. This work demonstrates a promising and sustainable strategy for producing branched cycloalkanes in the diesel and jet fuel range from lignocellulosic biomass-derived platform chemicals.

High-energy-density (HED) fuels are the power sources widely used in advanced aerospace propulsion systems. Cyclopentadiene (CPD) and its derivatives, characterized by high reactivity and strain cyclic carbon chain structure, have been widely used as the key precursors in the synthesis of HED fuels. This paper systematically summarized the research progress in the preparation of HED fuels using CPD and/or its derivatives as the feedstocks, with a focus on analyzing the synthetic routes, process characteristics, and differences in fuel performance. Based on the major challenges highlighted in current research (such as high costs, low efficiency, and the difficulty in simultaneously optimizing fuel properties), it was suggested that future developments should be focused on the exploration of efficient non-noble metal catalysts, the design of integrated reaction-separation processes, and the structure-performance relationships of fuel molecules. The aim of this review is to provide technological and theoretical guidance for the development of next-generation aerospace fuels with higher energy density and broad adaptability.

4-Hydroxycyclopent-2-enone (HCP), a chemical substance with a unique molecular structure and distinct physical properties, is an important intermediate for the synthesis of natural products, chemicals, and liquid fuels, demonstrating exceptionally high application value. This study introduces a novel approach for HCP synthesis via the rearrangement of furfuryl alcohol (FAL). A series of ZnAl-based hydrotalcite (HT) catalysts was prepared and characterized by SEM, XPS, XRD, NH3-TPD, and CO2-TPD. HCP is efficiently synthesized by the rearrangement of furfuryl alcohol in water at a relatively low temperature of 205 °C. Using a 10 wt.% aqueous solution of furfuryl alcohol as the raw material, the yield of HCP remained stable at 80.2% under the selected reaction conditions (ZnAl-HT-1: 1–500 °C as catalyst, 205 °C, and 5 min). It is worth noting that when the concentration of furfuryl alcohol solution was reduced to 5%, the conversion of furfuryl alcohol reached 100%, and the HCP yield reached an excellent 92.5%. The exceptional performance observed can be primarily attributed to several key factors associated with the ZnAl-HT-1: 1–500 °C catalyst: its expansive specific surface area and ample pore volume, the distinctive layered structure inherent to hydrotalcites, and its well-balanced acid–base properties, featuring optimal densities of acid and base sites with a uniform distribution of acidic and basic active centers that cooperate synergistically to promote the reaction.

Iron-based heterogenous catalysts play an important role in Fenton-like reactions, but their practical application is hindered by complex synthetic procedures and limited comprehension of reaction mechanisms. A straightforward impregnation and pyrolysis method was devised to synthesize a zero-valent iron (ZVI) modified carbonbased catalyst which significantly boosts PMS activation to degradation of tetracycline hydrochloride (TCH), more importantly, it elucidated the correlation between the electronic structure and the production of nonradical reactive oxygen species (ROS). The optimized catalyst demonstrates exceptional performance, achieving 97 % removal of TCH within 30 min, with a remarkable apparent rate constant (kobs) of 0.1962 min-1, outperforming the pristine carbon catalyst by 11-fold. Mechanistic investigations reveal that the incorporation of ZVI facilitates redox cycling with PMS, thereby boosting the generation of diverse ROS. Theoretical calculations reveal that both radical and non-radical pathways synergistically enhance catalytic activity. This work presents a cost-effective and scalable approach to designing high-performance carbon-based catalysts for PMS activation, providing valuable insights into the development of sustainable water purification technologies for emerging contaminants.

X80 pipeline steel easily corrodes during acid pickling. However, existing corrosion inhibitors exhibit uncertain toxicity and limited industrialization potential, and few corrosion inhibitors have been specifically designed for X80 pipeline steel. Building on previous studies, this study innovatively proposed Uncaria laevigata extract (ULE) as a potential corrosion inhibitor to address these drawbacks. The main active components of ULE, including alkaloids, flavonoids, and phenolic acids, were identified through spectroscopic characterization. Subsequently, comprehensive evaluation via weight loss and electrochemical tests revealed that ULE exhibited outstanding corrosion inhibition efficiency (>95%) and maintained excellent stability at various temperatures and during prolonged immersion for up to 196 h. Surface measurements (SEM, AFM, XPS, XRD and CA) confirmed that a protective film was generated by ULE on the steel surface, effectively isolating the corrosive medium. The adsorption behavior and corrosion inhibition mechanism of the main molecules from ULE were explained through molecular dynamics simulations and quantum chemical calculations. Importantly, a comprehensive toxicity assessment encompassing acute toxicity, antioxidant enzyme activities, and apoptosis-related gene expression levels was performed. ULE exhibited low acute toxicity (96 h-LC50 = 325.45 mg L-1) and caused no observable elevation in antioxidant-enzyme activities and apoptosis-related gene expression, demonstrating minimal oxidative stress and apoptotic impact and low toxicity for zebrafish. Compared to other plant extracts as well as synthetic and commercial corrosion inhibitors, this study presents ULE as a low cost, high efficiency, environmentally friendly alternative with excellent industrial potential.

In recent years, numerous methods have been reported for the preparation of bio-jet fuel. However, the cost remained the most vital determinant for the practical application of these methods. In 2019, our research team reported a synthetic process for bio-JP-10 fuel. It was suggested the production cost of bio-JP-10 fuel can be greatly reduced to $2547/ton that is significantly lower than the market price (similar to 7091 US$/ton) of fossil energy-based JP-10 fuel. However, energy consumption constituted as much as 42 % of the bio-JP-10 fuel production cost. In the present work, the initial 1,3-cyclopentanediol concentration in the dehydration step of the original route was amplified by six-fold by the optimization of solvent. Upon further optimization of reaction conditions, higher than 80 % cyclopentadiene carbon yields were achieved. Furthermore, a tandem reaction process involving the dehydration, Diels-Alder reaction and hydrogenation steps was developed, eliminating the need to separate the products. Both innovations considerably enhanced the production efficiency of bio-JP-10 fuel. Following the process simulation and energy balance of Aspen Plus 11, the energy consumption cost of bio-JP-10 fuel can be reduced by 67 %.

Environmentally friendly advanced oxidation (AOPs) is an effective means to treat trace amounts of antibiotics in water. However, traditional transition metal catalysts face challenges of metal leaching, limiting their practical utility. In this research, by activating peroxymonosulphate (PMS) using a nitrogen-phosphorus co-doped porous carbon (NP-HPMC-900) catalyst, a non-radical-dominated degradation mechanism was achieved. Material characterization revealed uniform distribution of N (3.35 at%) and P (2.56 at%) dopants in NP-HPMC-900, significantly enhancing the electronic structure and defect density (I-D/I-G = 0.86) of the carbon framework. Catalytic degradation experiments demonstrated that NP-HPMC-900 achieved 90 % tetracycline hydrochloride (TCH) removal within 30 min at pH 4, 6 and 10, with a superior apparent speed constant (k(obs) = 0.02671 min(-1)) compared to conventional metal-based catalysts. Density functional theory (DFT) calculations confirmed that NP doping modulated the local electron density of carbon matrix, enhancing its electron donor properties and PMS activation capability. Ecological toxicity assessments revealed significantly reduced phytotoxicity of degradation products, validating environmental safety. This study proposes a general strategy for activating PMS through N-P co-doped carbon materials from the perspective of catalyst-PMS synergistic degradation of pollutants, providing theoretical and practical insights into metal-free catalysts for sustainable water treatment.

The application of heterogeneous metal-free catalysis for non-radical peroxymonosulfate (PMS) oxidation is of great significance because of its low environmental effects and mild oxidant dosage. The purpose of this study was to investigate the activation mechanism of PMS using acid-modified activated carbon and oxytetracycline (OTC) as a representative pollutant. Modified activated carbon (MAC)/PMS system was capable of achieving 100 % degradation efficiency of OTC within 60 min, with an observed rate constant (kobs) of 0.0414 min-1. The degradation of OTC is dominated by non-radical oxidation pathways involved in mediated singlet oxygen (1O2) and electron-transfer process through electron paramagnetic resonance (EPR) and radicals quenching studies. The activation of PMS is attributed to the structural defects of MAC, persistent free radicals, and oxygen functional groups such as C-OOH. Moreover, the MAC/PMS system consistently demonstrates high and reliable contaminant removal in various water matrices. A continuous-flow device utilizing MAC shows excellent performance in purifying micro-polluted water. Additionally, the degradation pathways of pollutants and changes in toxicity during the degradation process were identified through density functional theory (DFT) calculations, liquid chromatography-mass spectrometry (LC-MS), and toxicological analysis. Finally, the cultivation of green beans, peas, and wheat was found to significantly decrease the toxicity of contaminated water through degradation. This study proposes a low-cost method to enhance the activation pathway of non-radical PMS by utilizing modified activated carbon materials for pollutant remediation.

Abstract Fe-based soft magnetic particles have excellent soft magnetic properties but have limitations in practical applications. In order to obtain better wave-absorbing properties, Fe-based soft magnetic particles have been modified to meet the demand for their properties. The wave-absorbing properties of Fe-based soft magnetic amorphous powders are improved by annealing them, because annealing not only increases the dielectric constant and permeability of the material but also improves the soft magnetic properties of the material and increases the impedance matching of electromagnetic waves. Compared with the as-prepared state, although the annealing treatment cannot increase the peak value of the wave absorption peak, it can make the wave absorption frequency domain wider and the area of the wave absorption peak larger. The samples annealed at 500°C have excellent wave-absorbing properties in the 8-10 GHz and 14-18 GHz bands.

Wood-derived carbons demonstrate great potential as self-standing electrodes in energy storage/conversion applications, including supercapacitors and water-splitting devices. However, the key challenge remains the rational customization of surface functionalities for optimized performance. This study introduces an innovative approach to self-standing wood-derived carbons with tailored nitrogen and metal functionalities. In contrast to traditional impregnation techniques, which offer limited precision in surface modification, this approach entails the intentional attachment of amidoxime groups to the wood substrates. These groups serve as nitrogen sources, and create abundant surface anchoring sites for metal ions due to the chelation between the amidoxime groups and metals. The resulting carbons feature uniform and high dispersion of nitrogen and metal functionalities, along with a distinctive hierarchical porosity combining interconnected open channels with abundant mesopores. As a proof-of-concept, different metals are incorporated (i.e., Mn, Co, Ni) into the amidoximated-wood precursors, and the resulting self-standing carbons showcase excellent performance in both supercapacitors and water-splitting applications. Leveraging the specific chelating ability of amidoxime groups toward metal ions, this strategy holds great potential as a generic approach to systematically tailoring the surface functionalities of carbon-based materials for various electrochemical energy storage/conversion processes. An efficient strategy for constructing a series of self-standing carbons using amidoximated-wood is presented. The amidoxime group enables the formation of diverse amidoximed-wood-metal complexes. Subsequent pyrolysis of these complexes yields self-standing metal/nitrogen-doped carbons featuring high metal loading and dispersion, along with interconnected channels and abundant mesopores. These self-standing carbons are highly efficient toward supercapacitor and water splitting. image

Spectroscopic single-molecule localization microscopy (sSMLM) simultaneously captures spatial localizations and spectral signatures, providing the ability of multiplexed and functional subcellular imaging applications. However, extracting accurate spectral information in sSMLM remains challenging due to the poor signal-to-noise ratio (SNR) of spectral images set by a limited photon budget from single-molecule fluorescence emission and inherent electronic noise during the image acquisition using digital cameras. Here, we report a novel spectrum-to-spectrum (Spec2Spec) framework, a self-supervised deep-learning network that can significantly suppress the noise and accurately recover low SNR emission spectra from a single-molecule localization event. A training strategy of Spec2Spec was designed for sSMLM data by exploiting correlated spectral information in spatially adjacent pixels, which contain independent noise. By validating the qualitative and quantitative performance of Spec2Spec on simulated and experimental sSMLM data, we demonstrated that Spec2Spec can improve the SNR and the structure similarity index measure (SSIM) of single-molecule spectra by about 6-fold and 3-fold, respectively, further facilitating 94.6% spectral classification accuracy and nearly 100% data utilization ratio in dual-color sSMLM imaging. A self-supervised deep-learning network (Spec2Spec) can efficiently remove noise and recover low signal-to-noise ratio fluorescence emission spectra from single-molecule emitters, facilitating multiplexed and functional super-resolution imaging.

Singlet oxygen (O-1(2)) is widely recognized as an effective reactive species for the targeted oxidation of organic contaminants. However, producing O-1(2) with high selectivity and efficiency remains a significant challenge. This study describes the synthesis of a N-C-loaded Fe catalyst (Fe/NC) loaded with nitrogen-doped carbon materials. The Fe/NC catalyst efficiently produces O-1(2) via the activation of peroxymonosulfate (PMS), demonstrating exceptional degradation capabilities for p-chlorophenol (4-CP). Compared to the control samples of nitrogen-doped carbon (NC) and Fe/NC-x under identical conditions, the Fe/NC/PMS produced a significantly greater degradation rate (0.794 min(-1)) for 4-CP (50 mg & sdot;L-1) within 14 min. The content of zinc was regulated to enhance the degradation of 4-CP. The durability of the catalyst was tested with a fixed-bed flow reactor, maintaining almost 100 % removal efficiency over 36 h on stream. The 4-CP degradation within this system was shown to be a non-radical process predominated by O-1(2) and electron transfer, as shown by electrochemical methods, quenching studies, and electron paramagnetic resonance test (EPR). Moreover, Fe/NC demonstrated exceptional resistance to pH changes (3-10), natural organics, and inorganic ions while degrading organic contaminants. The degradation process of 4-CP over the Fe/NC catalyst was examined using liquid chromatography-mass spectrometer. The results of the phytotoxicity evaluation indicated a significant decrease in their toxicity within the Fe/NC/PMS/4-CP system. The satisfactory activity, stability, and universality enabled Fe/NC to serve as a promising candidate for PMS activation. This study presents a novel approach for the selective production of O-1(2), enabling targeted pollutant degradation in wastewater treatment.

The efficient catalytic selective hydrogenation of furfural to produce 2-methylfuran was accomplished through the introduction of a small quantity of hydroquinone over a monometallic catalyst comprising solely of Co and its oxides.

2-methylfuran is a significant organic chemical raw material which can be produced by hydrolysis, dehydration, and selective hydrogenation of biomass hemicellulose. 2-methylfuran can be converted into value-added chemicals and liquid fuels. This article reviews the latest progress in the synthesis of liquid fuel precursors through hydroxyalkylation/alkylation reactions of 2-methylfuran and biomass-derived carbonyl compounds in recent years. 2-methylfuran reacts with olefins through Diels-Alder reactions to produce chemicals, and 2-methylfuran reacts with anhydrides (or carboxylic acids) to produce acylated products. In the future application of 2-methylfuran, developing high value-added chemicals and high-density liquid fuels are two good research directions.

Carbon-based solid acid catalysts were prepared from polycarbonate waste by methanolysis, polymerization with polyformaldehyde, calcination, and sulfonation. These catalysts were very active in the hydroxyalkylation/alkylation (HAA) reactions between 2-methylfuran (2-MF) and furfural. Under mild reaction conditions, the PC-180 catalyst produced a good yield (79.1%) of the HAA product from furfural and 2-MF, equivalent to that of Nafion resin (81.1%). The remarkable efficiency of PC-180 can be comprehended by its high acid content and enhanced hydrophilicity, as determined through scanning electron microscopy, contact angle measurement, and infrared spectroscopy. Furthermore, this catalyst proved to be universal in the HAA reactions of 2-MF with different carbonyl compounds. After hydrodeoxygenation over the Ni/AlPO4-800 catalyst, these HAA products can be selectively transformed into jet fuel and diesel range branched alkanes.

Formic acid (FA) is a prospective hydrogen storage agent, which has attracted much attention for its low toxicity and stability and plays a significant role in the comprehensive implementation of the hydrogen economy. In this regard, it is very important to utilize additive free FA dehydrogenation, for which few heterogeneous catalysts are available. Herein, we report ultra-small PdAuIr nanoparticles (NPs) supported on amine-based amorphous porous organic polymers (POPs), which exhibit excellent FA dehydrogenation activity with an initial total turnover number (TOF) of 9635 h-1 without additives at room temperature and apparent activation energy (Eaapp) of 36.5 kJ/mol. The results show that the excellent performance can be attributed to the synergistic effect of trimetallic alloys and strong metal-support interaction effect (SMSI), as well as to the amine groups (-NH2) grafted on POPs which facilitates the O-H bond splitting on FA. Overall, the simple and efficient synthetic strategy provides a new method for the selective dehydrogenation of FA.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

A potentially viable strategy for the fabrication of efficient sorbents for CO 2 capture is the use of porous carbons obtained from biomass, which have a large surface area and delicately organized porous structural framework.

Dehydrogenation of formic acid (FA) represents a promising route for clean hydrogen production, the economic viability of which, however, is largely hindered by the catalyst inefficiency. Here, ultrafine Au-Pd bimetallic nanoclusters (NCs) confined within the cavities of bipyridyl covalent triazine frameworks (CTFs) are constructed via a metal-nitrogen coordination reduction strategy, which is enabled by the chelation between bidentate nitrogen sites of the bipyridine ligands and metal ion precursors. The resulting CTF-confined PdAu NCs exhibit a high initial turnover frequency up to 12,368 h-1 (333 K) toward the dehydrogenation of FA without any additives. The experimental and theoretical studies disclose that the pyridinic nitrogen sites of CTF not only facilitate the formation of monodisperse small-sized metal NCs via the anchoring and the pore confinement effect but also serve as a proton buffer which can store excess protons and thus suppress the recombination of adsorbed formate and hydrogen on the PdAu alloy surface. These findings would have significant implications for designing high-performance hydrogen production catalysts.

Formic acid(FA)has come to be considered a potential candidate for hydrogen storage,and the develop-ment of efficient catalysts for H2 releasing is crucial for realizing the sustainable process from FA.Herein,we have developed the ultrafine Pd nanoparticle(NPs)with amine-functionalized carbon as a support,which was found to show an excellent catalytic activity in H2 generation from FA dehydrogenation.The synergetic mechanism between amine-group and Pd active site was demonstrated to facilitate H2 generation by β-hydride elimination.Moreover,the texture of support for Pd NPs also plays an important role in determining the reactivity of FA,since the diffusion of gaseous products makes the kinetics of dif-fusion as a challenge in this high performance Pd catalysts.As a result,the as-prepared Pd/NH2-TPC cat-alyst with the small sized Pd nanoparticles and the hierarchically porous structures shows a turnover of frequency(TOF)value of 4312 h-1 for the additive-free FA dehydrogenation at room temperature,which is comparable to the most promising heterogeneous catalysts.Our results demonstrated that the intrinsic catalytic activities of active site as well as the porous structure of support are both important factors in determining catalytic performances in H2 generation from FA dehydrogenation,which is also helpful to develop high-activity catalysts for other advanced gas-liquid-solid reactions systems.