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Heterogeneous thermal-catalytic CO2 hydrogenation to alcohols using renewable energy is a highly attractive approach for recycling greenhouse gases into high-value chemicals and fuels, thereby reducing the dependence on fossil fuels, while simultaneously mitigating the CO2 emission and environmental problems. Currently, great advances have been made on the heterogeneous catalysts, but an in-depth and more comprehensive understanding to further promote this reaction process is still lacking. Herein, we highlight the thermodynamic and kinetic analysis of CO2 hydrogenation reaction firstly. Then, various reaction pathways for CO2 hydrogenation to methanol and higher alcohols (C2+ alcohols) have been discussed in detail, respectively, by combining the experimental studies and density functional theory calculations. On this basis, the key factors influencing the reaction performance, such as metal dispersion, support modification, promoter addition and their structural optimization, are summarized on the metal-based and metal-oxide-based catalysts. In addition, the catalytic performance of CO2 hydrogenation to alcohols and the relationship between structure and properties are mainly summarized and analyzed in the past five years. To conclude, the current challenges and potential strategies in catalyst design, structural characterization and reaction mechanisms are presented for CO2 hydrogenation to alcohols. [ABSTRACT FROM AUTHOR]

The electricity generated from renewable resource such as solar energy and wind energy is used to generate chemicals, fuels and hydrogen resources by electrocatalytic reduction of CO 2 with M 2 β 12 to achieve the goal of carbon neutrality. [Display omitted] • The BACs formed on β 12 -borophene supported homonuclear bimetallic showed good stability and conductivity. • The overpotential of Fe 2 β 12 and Ag 2 β 12 produce CO is only 0.05 V, and Fe 2 β 12 is beneficial for electrocatalytic production of syngas. • The overpotential of Cu 2 β 12 and Ag 2 β 12 for HCOOH production was as low as 0.001 and 0.07 V. • Catalytic performance of Rh 2 β 12 in electroreduction of CO 2 to CH 3 OH and CH 4 is also encouraging, with overpotential of 0.51 and 0.65 V. • Ag 2 β 12 generates CH 3 CH 2 OH through *CO-*CHO coupling path with the overpotential of 0.60 V. Bimetal atom catalysts (BACs) hold significant potential for various applications as a result of the synergistic interaction between adjacent metal atoms. This interaction leads to improved catalytic performance, while simultaneously maintaining high atomic efficiency and exceptional selectivity, similar to single atom catalysts (SACs). Bimetallic site catalysts (M 2 β 12) supported by β 12 -borophene were developed as catalysts for electrocatalytic carbon dioxide reduction reaction (CO 2 RR). The research on density functional theory (DFT) demonstrates that M 2 β 12 exhibits exceptional stability, conductivity, and catalytic activity. Investigating the most efficient reaction pathway for CO 2 RR by analyzing the Gibbs free energy (ΔG) during potential determining steps (PDS) and choosing a catalyst with outstanding catalytic performance for CO 2 RR. The overpotential required for Fe 2 β 12 and Ag 2 β 12 to generate CO is merely 0.05 V. This implies that the conversion of CO 2 to CO can be accomplished with minimal additional voltage. The overpotential values for Cu 2 β 12 and Ag 2 β 12 during the formation of HCOOH were merely 0.001 and 0.07 V, respectively. Furthermore, the Rh 2 β 12 catalyst exhibits a relatively low overpotential of 0.51 V for CH 3 OH and 0.65 V for CH 4. The Fe 2 β 12 produces C 2 H 4 through the *CO-*CO pathway, while Ag 2 β 12 generates CH 3 CH 2 OH via the *CO-*CHO coupling pathway, with remarkably low overpotentials of 0.84 and 0.60 V, respectively. The study provides valuable insights for the systematic design and screening of electrocatalysts for CO 2 RR that exhibit exceptional catalytic performance and selectivity. [ABSTRACT FROM AUTHOR]

[Display omitted] • The chelation of –NH 2 to metal ions enhances the formation of small Co 3 O 4 particles. • N doping regulates the valence states of Co and oxygen vacancies. • The presence of Brønsted and Lewis acid sites promotes the adsorption of C 8 H 8. • The oxidation reactions are mainly dominated by the Mars-van Krevelen mechanism. • Good C 8 H 8 oxidation activity, thermal stability and water-resistance are achieved over CS/Co 3 O 4 -W. In this study, a Co 3 O 4 catalyst is synthesised using the chitosan-assisted sol–gel method, which simultaneously regulates the grain size, Co valence and surface acidity of the catalyst through a chitosan functional group. The complexation of the free –NH 2 complex inhibits particle agglomeration; thus, the average particle size of the catalyst decreases from 82 to 31 nm. Concurrently, Raman spectroscopy, hydrogen temperature-programmed reduction, electron paramagnetic resonance spectroscopy and X-ray photoelectron spectroscopy experiments demonstrate that doping with chitosan N sources effectively modulates Co2+ to promote the formation of oxygen vacancies. In addition, water washing after catalyst preparation can considerably improve the low-temperature (below 250 °C) activity of the catalyst and eliminate the side effects of alkali metal on catalyst activity. Moreover, the presence of Brønsted and Lewis acid sites promotes the adsorption of C 8 H 8. Consequently, CS/Co 3 O 4 -W presents the highest catalytic oxidation activity for C 8 H 8 at low temperatures (R 250 °C = 8.33 μmol g−1 s−1, WHSV = 120,000 mL hr−1∙g−1). In situ DRIFTS and 18O 2 isotope experiments demonstrate that the oxidation of the C 8 H 8 reaction is primarily dominated by the Mars–van Krevelen mechanism. Furthermore, CS/Co 3 O 4 -W exhibits superior water resistance (1- and 2- vol% H 2 O), which has the potential to be implemented in industrial applications. [ABSTRACT FROM AUTHOR]

¹H-NMR spectroscopy was used to monitor the reactions of an arylidene 2-thiohydantoin derivative, 3-((phenylmethylene)amino)-2-thioxo-4-imidazolidinone (3), with PdCl2, cis-[PdCl2(dmso-S)2] and K2[PdCl4] in DMSO-d6 in order to elucidate the reaction kinetics and mechanism. The 2-thiohydantoin derivative 3 formed cis-[Pd(3-N,S)(dmso-S)2]+ complex (5) in reactions with PdCl2 and cis-[PdCl2(dmso-S)2], while no reaction with K2[PdCl4] was observed. A two-step mechanism for the reactions of 3 with PdCl2 and cis--[PdCl2(dmso-S)2] is proposed, in which fast coordination to the side chain nitrogen occurs in the first step, while chelation and coordination to the sulfur atom in the 2-thiohydantoin ring is the second, slower, rate-determining step. The reaction rate constants were calculated and reactivities of the 2-thiohydantoin derivative 3 towards the palladium(II) salts were compared and discussed. Reaction of 3 with cis-[PdCl2(dmso-S)2] was faster than with PdCl2. The investigated palladium(II) salts also react with the solvent, DMSO-d6, and the influence of these side reactions on the outcome and kinetics of the 2-thiohydantoin derivative complexation reaction is discussed in detail. The obtained results of this study can have an impact in explanation of the coordination behavior of antitumor active palladium(II) and platinum(II) complexes. [ABSTRACT FROM AUTHOR]

The wet dissolution process of lime is an effective approach for synthesizing calcium hydroxide. Process parameters and additives exert influence on the product particle. Among the process parameters, lime particle size, reaction temperature, and time have a significant impact on product particle size, followed by liquid‐solid ratio and stirring speed. The experiment proved that reaction time affects product particle size by affecting the crystal growth, while other process parameters affect the particle size by affecting the ion diffusion behavior. In terms of inorganic additives, Ca(OH)2 has minimal effect on product particle size; however, NaOH and CaCl2 can significantly enhance it with a greater dose leading to a larger increase. The experiment proved that Ca(OH)2, NaOH, and CaCl2 influence particle size through their impact on ion diffusion behavior. Regarding organic additives, soluble starch exhibits the greatest effect on product size followed by triethanolamine and polyvinylpyrrolidone K30. The experiment proved that soluble starch, triethanolamine, and polyvinylpyrrolidone K30 affect product particle size by influencing its crystallization position. Finally, an ultrafine slurry of calcium hydroxide was prepared using the lime wet digestion method based on the aforementioned research, with particle size distribution characterized by D10, D50, and D90 values of 0.303, 1.750, and 4.534 µm respectively. [ABSTRACT FROM AUTHOR]

The microbial characteristics of sulfur autotrophic denitrification system was systematically expounded. The advantages of sulfur autotrophic denitrifying microorganisms in different reactors and the functional enzymes of inorganic sulfur source redox were analyzed. The methods of accelerating sulfur autotrophic denitrification were introduced, such as reducing the particle size of S0 particles, applied magnetic field, adding sulfur metabolism intermediates or cattle serum protein. The practical engineering application of sulfur autotrophic denitrification at home and abroad was mainly summarized. The future development direction of sulfur autotrophic denitrification technology was prospected. It was aimed to provide reference for the development of sulfur autotrophic denitrification system. [ABSTRACT FROM AUTHOR]

The derivatives of 1,2,4- triazole have attracted great attention among medicinal chemists due to their wide range of biological activity, good pharmacodynamic and pharmacokinetic profiles, and low toxicity, that necessitates the development of various synthesis methods and a comprehensive study of their reaction mechanisms. A detailed investigation of possible pathways for formation of new spiro-condensed [1,2,4]triazolo[1,5-c]quinazolines, that combine two structural domains with different biological properties, was performed by computational study at the SMD/B3lyp/6-31+G(d) theory level. The mechanism of interaction between [2-(3-hetaryl-1,2,4-triazol-5-yl)phenyl]amine and cyclohexanone in methanol involves three main processes: formation of carbinolamine by addition of an amine to double bond C=O, elimination of a water molecule, and intramolecular cyclization leading to formation of spiro compounds. Results show increase in reactivity of reactants during acid-catalyzed reaction compared to uncatalyzed one. The nature of the heterocyclic substituent on the triazole ring has little effect on the reaction energy, while the mechanism is unchanged. [ABSTRACT FROM AUTHOR]

Aryl carbamates exhibit significant utility due to their diverse range of biological activities, including anticancer, antituberculosis, and antioxidant properties. This study will focus on a comparative evaluation of the antioxidant capabilities of two aryl carbamate derivatives, namely Methyl(Z)-(1-(hydroxyamino) ethyl)-5-(methoxycarbonyl) amino)-2-methyl-1H-indole 1 carboxylate (Compound 1) and Dimethyl (1,3-dioxo-2,3-dihydro-1H-indene-2,2-diyl) bis (4,1 phenylene) dicarbamate (Compound 2). To assess the anti-oxidant capacity, two distinct reactive oxygen species, such as highly reactive hydroxyl (HO·) and moderately reactive hydroperoxyl (HOO·), have been taken into consideration. Four distinct scavenging processes, including RAF, HAT, SETPT, and SPLET, have been investigated here. The RAF mechanism was determined to be the most effective anti-oxidant pathway, regardless of the compounds or free radicals investigated here. For both HO· and HOO·, compound 1 demonstrated more potent scavenging capabilities than compound 2. Compounds 1 and 2 react with the HO· radical very quickly due to its extraordinarily high reactivity; in contrast, the less reactive HOO· provides a rather moderate rate. The calculated values of overall rate constant of Comp. 1 reaction with HOO· are 3.7 × 103 M−1 s−1 (gas phase), 5.3 × 101 M−1 s−1 (water), and 3.6 × 100 M−1 s−1 (pentyl ethanoate). With this context it is clear both of the compounds can work as strong and mild antioxidant against HO· and HOO· radical, respectively. [ABSTRACT FROM AUTHOR]

The green electricity‐driven electrocatalytic reduction of organic compounds in aqueous solution has merged as a sustainable and green platform for organic electrosynthesis, upcycling of chemical waste, and environmental remediation. Compared with the thermocatalytic hydrogenation process, the electrocatalytic reduction of organic compounds uses water as a proton source, which enables its operation at ambient conditions with simplified reaction schemes and significantly reduces operation cost and energy consumption. Most studies have demonstrated the development of electrocatalysts to boost the current efficiency, conversion, and product selectivity of the electrocatalytic reduction processes. Still, little attention has been paid to the mechanism (e. g. electron/proton transfer route) and related energetics behind the electrocatalytic reduction process. This Concept overviews the recent development of the electrocatalytic reduction systems for environmental remediation, pollutant upcycling, and valorization of biomass‐derived chemicals. This Concept highlights the underlying mechanisms and aims to provide instructive guidance on designing efficient and selective electrocatalytic systems. [ABSTRACT FROM AUTHOR]

The electrocatalytic synthesis of C–N coupling compounds from CO2 and nitrogenous species not only offers an effective avenue to achieve carbon neutrality and reduce environmental pollution, but also establishes a route to synthesize valuable chemicals, such as urea, amide, and amine. This innovative approach expands the application range and product categories beyond simple carbonaceous species in electrocatalytic CO2 reduction, which is becoming a rapidly advancing field. This review summarizes the research progress in electrocatalytic urea synthesis, using N2, NO2−, and NO3− as nitrogenous species, and explores emerging trends in the electrosynthesis of amide and amine from CO2 and nitrogen species. Additionally, the future opportunities in this field are highlighted, including electrosynthesis of amino acids and other compounds containing C–N bonds, anodic C–N coupling reactions beyond water oxidation, and the catalytic mechanism of corresponding reactions. This critical review also captures the insights aimed at accelerating the development of electrochemical C–N coupling reactions, confirming the superiority of this electrochemical method over the traditional techniques. [ABSTRACT FROM AUTHOR]

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Copyright of Energy Chemical Industry is the property of Energy Chemical Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The combined quantum mechanics/molecular mechanics method is most often used to describe the molecular mechanisms of enzymatic reactions. The review discusses the main methodological issues, gives practical recommendations, and also illustrates the progress of the method over the past 20 years using an important example of the reaction of guanosine triphosphate hydrolysis by a protein complex. [ABSTRACT FROM AUTHOR]

The decomposition rates of diphenylfuroxane and a number of 4-nitro-3-alkyl-furoxanes in dilute solutions are measured by the manometric and calorimetric methods. An increase in the reaction rate with an increase in the polarity of the solvent is not detected in any instance, which corresponds to the absence of an increase in the dipole moment of the molecule during the formation of a transition state (TS). Based on this result, a conclusion is made about the biradical (BR) mechanism of the decomposition of uncondensed disubstituted furoxanes (FOs) in solutions. [ABSTRACT FROM AUTHOR]

Caged compounds are frequently used in life science research. However, the light used to activate them is commonly absorbed and scattered by biological materials, limiting their use to basic research in cells or small animals. In contrast, hard X‐rays exhibit high bio‐permeability due to the difficulty of interacting with biological molecules. With the main goal of developing X‐ray activatable caged compounds, azo compounds are designed and synthesized with a positive charge and long π‐conjugated system to increase the reaction efficiency with hydrated electrons. The azo bonds in the designed compounds are selectively cleaved by X‐ray, and the fluorescent substance Diethyl Rhodamine is released. Based on the results of experiments and quantum chemical calculations, azo bond cleavage is assumed to occur via a two‐step process: a two‐electron reduction of the azo bond followed by N─N bond cleavage. Cellular experiments also demonstrate that the azo bonds can be cleaved intracellularly. Thus, caged compounds that can be activated by an azo bond cleavage reaction promoted by X‐ray are successfully generated. [ABSTRACT FROM AUTHOR]

The electronic structure of metal complexes plays key roles in determining their catalytic features. However, controlling electronic structures to regulate reaction mechanisms is of fundamental interest but has been rarely presented. Herein, we report electronic tuning of Cu porphyrins to switch pathways of the hydrogen evolution reaction (HER). Through controllable and regioselective β‐oxidation of Cu porphyrin 1, we synthesized analogues 2–4 with one or two β‐lactone groups in either a cis or trans configuration. Complexes 1–4 have the same Cu‐N4 core site but different electronic structures. Although β‐oxidation led to large anodic shifts of reductions, 1–4 displayed similar HER activities in terms of close overpotentials. With electrochemical, chemical and theoretical results, we show that the catalytically active species switches from a CuI species for 1 to a Cu0 species for 4. This work is thus significant to present mechanism‐controllable HER via electronic tuning of catalysts. [ABSTRACT FROM AUTHOR]

The catalysts for oxygen reduction reaction (ORR) are of great significance to the development of electrochemical energy systems. In this paper, the ORR catalytic performance of Mn–Ni dual-metal doped N-coordinated graphene is studied by density functional theory (DFT). The results show that the catalysts with dual-metal active sites are more stable than that with single metal site, and all catalysts show certain catalytic activity. The reaction pathway analyses of catalysts with two different adsorption configurations of O 2 show that when O 2 is adsorbed on two metal sites, OOH will automatically split into OH and O. When O 2 is adsorbed on Mn site alone, the other site does not participate in the adsorption of oxygen-containing intermediates. The thermodynamic calculation results show that the catalytic performance is mainly influenced by the adsorption strength of O, which is controlled by the number of active sites involved in the adsorption, bond length and the number of transferred electrons at the active sites. The G-MnNiN 6 -3 shows the best catalytic performance with an overpotential of 0.453 V and a reaction energy barrier of 0.19 eV. The results of this study highlight the potential application of Mn–Ni dual-metal doped N-coordinated graphene as a highly efficient non-precious catalyst. • The ORR catalytic performance of Mn–Ni dual-metal doped N-coordinated graphene is studied for the first time. • The adsorption of O 2 can be classified into single adsorption and co-adsorption on bimetallic catalyst. • The catalytic performance is most affected by the adsorption strength of O. • The best catalyst shows the overpotential of 0.453 V and a reaction energy barrier of 0.19 eV. [ABSTRACT FROM AUTHOR]

Free radicals produced due to the disturbance in homeostasis bring about oxidative stress causing various diseases. This oxidative stress can be prevented by using antioxidants. In this article, a hexaazacylcododeca copper complex is reported as a radical‐trapping antioxidant (RTA). A detailed mechanistic study suggests that the designed complex is capable of trapping six radicals. The study confirms Path 6 as the most probable pathway, which is the radical addition to the ethene moiety of the complex. Moreover, it has a lower N−H bond dissociation enthalpy (BDE) than the recently reported bis(thiosemicarbazone) copper complex suggesting it could be a better antioxidant. In addition, the effect of different metals (Co, Fe, Pt, Ca, Ba, Sr, Au, Ag, Ni, and Zn) in their antiradical activity has been studied which suggests that among the studied metal complexes the Cu metal complex is the best metal complex for radical trapping. Further, the drug‐likeness is tested with the Lipinski filter along with the absorption, distribution, metabolism, and excretion (ADME) properties. Lastly, docking analysis tested against proteins responsible for ferroptosis shows that the modeled RTA can inhibit such diseases. Thus, it can be proposed that the designed RTA is a potential drug candidate. [ABSTRACT FROM AUTHOR]

Detailed reaction mechanisms of 4‐(N‐methyl)pyridinium boronic acid (1) and anthracene‐bridged bis(pyridinium boronic acid) compounds (diboronic acids 2 and 3) with D‐glucose were kinetically investigated in aqueous methanolic solutions. The crystal structure of diboronic acid 3 was determined using X‐ray crystallography. The pKa values of the two boronic acid moieties of diboronic acid (2 or 3) differed by one unit, indicating electronic interactions between the two boronic acid moieties. The kinetics of the reaction of boronic acid 1 with D‐glucose showed that both trigonal boronic acid and tetrahedral boronate ions were reactive with D‐glucose. UV‐Vis spectrophotometry and 1H NMR spectrometry of the reactions of phenylboronic acid with some model compounds of D‐glucose showed that the reactive moiety of α‐D‐glucofuranose towards phenylboronic acid was not the 1,2‐diol site, but the 3,5,6‐triol site. In the reactions of diboronic acids 2 and 3 with D‐glucose, the 3,5,6‐triol site of α‐D‐glucofuranose reacts first with one of the two equivalent boronic acid moieties of diboronic acid to form a 3,5‐bicoordinate intermediate as a rate‐determining step, followed by the reaction of the 1,2‐diol site of α‐D‐glucofuranose with another boronic acid moiety of diboronic acid to form the final 1,2 : 3,5‐tetracoordinate cyclic compound as a fast step. [ABSTRACT FROM AUTHOR]

Considering the importance of understanding the catalysis of metal oxides incorporated hydrogen storage system MgH 2 , in this study we tried to identify the chemical interaction between magnesium hydride (MgH 2) and the additive vanadium pentoxide (V 2 O 5). Two test samples, MgH 2 +0.25V 2 O 5 and 0.25MgH 2 +V 2 O 5 , were subjected to mechanical milling treatment for different times (15 min, 1h, 2h, 5h, 10h and 15h), and the phase change was monitored systematically. The detailed X ray diffraction analyses suggest that the phase evolution starts with the reduction of V 2 O 5 and it ends up with the formation of a rock salt structure, typified by Mg x V y O x + y. High-resolution transmission electron microscopy study coupled with energy dispersive spectroscopy suggest that the distribution of V, Mg and O in Mg x V y O x + y is homogenous, though V-rich spots/boundaries can be spotted across the rock salt particles. Further verification by X–ray photoelectron spectroscopy suggests that V exists in a mixed valence state in the end sample, 15h reacted MgH 2 +0.25V 2 O 5. Differential scanning calorimetry and hydrogen storage kinetics studies prove the improved hydrogen storage behavior of Mg x V y O x + y containing MgH 2 sample. We believe that the formation of Mg x V y O x + y rock salt particles with V enriched spots/interfaces is the key step in the catalysis of V 2 O 5 incorporated hydrogen storage system, MgH 2. • The catalytic interaction between MgH 2 and the additive V 2 O 5 makes Mg gets oxidized and V gets reduced. • The interaction also leads to the in-situ formation of V doped MgO rock salt particles. • Existence of V rich surface spots on the V doped MgO particles can be confirmed. • The particle surface contains V with variable oxidation states. • V doped MgO is catalytically active for MgH 2. [ABSTRACT FROM AUTHOR]

In this study, we employ density functional theory (DFT) to explore the structural properties of g-C 3 N 4 and its bimetallic modified catalysts by introducing the bimetallic atoms (Rh@Pt, Ru@Pd, Pd@Pt, Ru@Pt, Ph@Pd) to the g-C 3 N 4 surface. In addition, we explore three potential reaction pathways catalyzed by these six catalysts for the dehydrogenation reaction of ammonia borane. We find the optimal reaction pathway by comparing the activation energy of the rate-limiting steps in several reaction paths. Our findings demonstrate that bimetal Rh@Pt, Ru@Pd, Pd@Pt, Ru@Pt, Ph@Pd supported by g-C 3 N 4 can enhance catalytic activity of ammonia borane hydrogen evolution. We also investigate the reasons contributing to the improved catalytic activity of these five modified catalysts and find that Rh@Pt supported by g-C 3 N 4 exhibits the best catalytic performance. Additionally, we study the band structure and density of states (DOS) of six catalysts and observe an increased degree of metallicity in the modified catalysts. Overall, we establish the correlation between the reaction activities of ammonia borane hydrogen evolution and the physical properties of the catalysts. This work is intended to provide a theoretical basis for optimizing catalysts for the dehydrogenation reaction of ammonia borane. Five modified catalysts were constructed by incorporating bimetal atoms onto g-C 3 N 4 surface. and the mechanism of ammonia borane dehydrogenation catalyzed by g-C 3 N 4 and five modified catalysts was investigated. The investigation uncovered the fundamental cause underlying the enhanced catalytic performance of the modified catalyst. [Display omitted] • Five modified catalysts were constructed by incorporating bimetal atoms onto g-C 3 N 4 surface. • The mechanism of ammonia borane dehydrogenation catalyzed by g-C 3 N 4 and five modified catalysts was investigated. • This investigation uncovered the fundamental cause underlying the enhanced catalytic performance of the modified catalyst. [ABSTRACT FROM AUTHOR]

Opting for NO as an N source in electrocatalytic NH3 synthesis presents an intriguing approach to tackle energy and environmental challenges. However, blindly pursuing high NH3 synthesis rates and Faradaic efficiency (FE) while ignoring the NO conversion ratio could result in environmental problems. Herein, Cu nanosheets with exposed (111) surface is fabricated and exhibit a NO‐to‐NH3 yield rate of 371.89 μmol cm−2 h−1 (flow cell) and the highest FE of 93.19±1.99 % (H‐type cell). The NO conversion ratio is increased to the current highest value of 63.74 % combined with the development of the flow cell. Additionally, Crystal Orbital Hamilton Population (COHP) clearly reveals that the "σ‐π* acceptance‐donation" is the essence of the interaction between the Cu and NO as also supported by operando attenuated total reflection infrared spectroscopy (ATR‐IRAS) in observing the key intermediate of NO−. This work not only achieves a milestone NO conversion ratio for electrocatalytic NO‐to‐NH3, but also proposes a new descriptor that utilizes orbital hybridization between molecules and metal centers to accurately identify the real active sites of catalysts. [ABSTRACT FROM AUTHOR]

Phosphinidenes are heavy congeners of nitrenes that have been broadly used as in situ reagents in synthetic phosphorus chemistry and also serve as versatile ligands in coordination with transition metals. However, the detection of free phosphinidenes is largely challenged by their high reactivity and also the lack of suitable synthetic methods, rendering the knowledge about the fundamental properties of this class of low‐valent phosphorus compounds limited. Recently, an increasing number of free phosphinidenes bearing prototype structural and bonding properties have been prepared for the first time, thus enabling the exploration of their distinct reactivity from the nitrene analogues. This Concept article will discuss the experimental approaches for the generation of the highly unstable phosphinidenes and highlight their distinct reactivity from the nitrogen analogues so as to stimuate future studies about their potential applications in phosphorus chemistry. [ABSTRACT FROM AUTHOR]

Combined pollutants, such as organic–heavy metal contaminants, are recalcitrant and commonly detected toxic compounds in aquatic environments. In this study, immobilized beads were prepared by coupling power activated carbon, zero-valent iron (ZVI), and nitrosamine–degrading bacteria and used to simultaneously remove nitrosamine–hexavalent chromium (Cr(VI)) combined pollutants. The highest removal ratios were 25.8–98.8% (nitrosamines) and 81.8% (Cr(VI)) within an empty bed contact time. The nitrosamine degradation kinetics ft a pseudo-second-order model well (R2 2≥0.8812) and the rate constant k2 for the fve linear nitrosamines removal partially scaled with their molecular weights and LogKow (R2=0.745 and 0.6908). Interestingly, nitrosamines promoted Cr(VI) removal by the beads, while Cr(VI) inhibited nitrosamine degradation. The removal of the linear nitrosamines and Cr(VI) was enhanced under acidic conditions at room temperature, whereas dissolved oxygen and humic acid inhibited both. In the presence of mono- or mixed anions (NO2 −, CO3 2− − enhanced the removal of all nitrosamines. Furthermore, mono-anion promoted Cr(VI) removal, while all four anions decreased the Cr(VI) removal efciency. The reaction mechanism revealed that nitrosamines were primarily transformed into secondary amines, methylamine, nitrate, and ammonia by ZVI and nitrosamine–degrading bacteria; Cr(VI) was reduced to Cr(III) by ZVI. Further, the synergistic reaction between nitrosamines and Cr(VI) also played an important role in their removal. The results of this study improve our understanding of nitrosamine–Cr(VI) removal by immobilized beads, which can further be applied to treat combined groundwater pollution. [ABSTRACT FROM AUTHOR]4 2−), the removal efciencies of the fve linear nitrosamines were reduced, while that of NMor increased. NO3 − enhanced the removal of all nitrosamines. Furthermore, mono-anion promoted Cr(VI) removal, while all four anions decreased the Cr(VI) removal efciency. The reaction mechanism revealed that nitrosamines were primarily transformed into secondary amines, methylamine, nitrate, and ammonia by ZVI and nitrosamine–degrading bacteria; Cr(VI) was reduced to Cr(III) by ZVI. Further, the synergistic reaction between nitrosamines and Cr(VI) also played an important role in their removal. The results of this study improve our understanding of nitrosamine–Cr(VI) removal by immobilized beads, which can further be applied to treat combined groundwater pollution. [ABSTRACT FROM AUTHOR]

The synthesis process of conventional Mn-based denitrification catalysts is relatively complex and expensive. In this paper, a resource application of chlorella was proposed, and a Chlorella@Mn composite denitrification catalyst was innovatively synthesized by electrostatic interaction. The Chlorella@Mn composite denitrification catalyst prepared under the optimal conditions (0.54 g/L Mn2+ concentration, 20 million chlorellas/mL concentration, 450°C calcination temperature) exhibited a well-developed pore structure and large specific surface area (122 m2/g). Compared with MnOx alone, the Chlorella@Mn composite catalyst achieved superior performance, with ∼100% NH 3 selective catalytic reduction (NH 3 -SCR) denitrification activity at 100-225°C. The results of NH 3 temperature-programmed desorption (NH 3 -TPD) and H 2 temperature-programmed reduction (H 2 -TPR) showed that the catalyst had strong acid sites and good redox properties. Zeta potential testing showed that the electronegativity of the chlorella cell surface could be used to enrich with Mn2+. X-ray photoelectron spectroscopy (XPS) confirmed that Chlorella@Mn had a high content of Mn3+ and surface chemisorbed oxygen. In-situ diffuse reflectance infrared Fourier transform spectroscopy (in-situ DRIFTS) experimental results showed that both Langmuir-Hinshelwood (L-H) and Eley-Rideal (E-R) mechanisms play a role in the denitrification process on the surface of the Chlorella@Mn catalyst, where the main intermediate nitrate species is monodentate nitrite. The presence of SO 2 promoted the generation and strengthening of Brønsted acid sites, but also generated more sulfate species on the surface, thereby reducing the denitrification activity of the Chlorella@Mn catalyst. The Chlorella@Mn composite catalyst had the characteristics of short preparation time, simple process and low cost, making it promising for industrial application. [Display omitted] Schematic diagram of NH 3 -SCR performance of Chlorella@Mn composite denitrification catalyst. [ABSTRACT FROM AUTHOR]

Chemistry is no longer a pure experimental science. Theoretical calculations and chemical experiments can be used to study the properties of compounds and chemical reactions from different perspectives. Now, calculation is an important branch of chemical research. In this manuscript, through a specific calculation study on the mechanism of CO2 functionalization reduction reaction of aniline, the basic methods and processes of quantum calculation are introduced and some reaction details that are easily overlooked or cannot be discovered during the experimental process are discovered by analyzing the calculation results. [ABSTRACT FROM AUTHOR]

In this research, a solvent thermal dechlorination method was adopted to remove chlorine from polyvinyl chloride (PVC) material, using ethylene glycol (EG) as solvent and adding alkaline additives, so as to improve the dechlorination efficiency and reduce the reaction temperature. KOH, NaOH and K 2 CO 3 were selected as additives and their dechlorination activity was found to decrease in the following order: K 2 CO 3 >KOH>NaOH. Afterward, the effect of K 2 CO 3 concentration, reaction temperature and reaction time on the dechlorination of PVC was studied and a novel dechlorination mechanism was investigated. The results showed that solvothermal dechlorination may accomplish efficient dechlorination at low temperatures. The reaction temperature can be reduced to 180 ℃ in 0.5 M K 2 CO 3 /EG system with a solid-liquid ratio of 1:40(g:ml) and more than 97% dichlorination, which is 10 ℃ lower than the lowest temperature reported in published literature. Through the characterization and analysis of solid products, the dechlorination mechanism of PVC in K 2 CO 3 /EG system was proposed. Glycolate ion and OH- may be formed in the reaction and they both work to dechlorinate PVC by removing the Cl through two distinct substitution reactions. [Display omitted] [ABSTRACT FROM AUTHOR]

Biochar (BC) is a new type of carbon material with a high specific surface area, porous structure, and good adsorption capacity, which can effectively adsorb and enrich organic pollutants. Meanwhile, nano zero-valent iron (nZVI) has excellent catalytic activity and can rapidly degrade organic pollutants through reduction and oxidation reactions. The combined utilization of BC and nZVI can not only give full play to their advantages in the adsorption and catalytic degradation of organic pollutants, but also help to reduce the agglomeration of nZVI, thus improving its efficiency in water treatment and providing strong technical support for water resources protection and environmental quality improvement. This article provides a detailed introduction to the preparation method and characterization technology, reaction mechanism, influencing factors, and specific applications of BC and nZVI, and elaborates on the research progress of BC-nZVI in activating persulfate (PS) to degrade organic pollutants in water. It has been proven experimentally that BC-nZVI can effectively remove phenols, dyes, pesticides, and other organic pollutants. Meanwhile, in response to the existing problems in current research, this article proposes future research directions and challenges, and summarizes the application prospects and development trends of BC-nZVI in water treatment. In summary, BC-nZVI-activated PS is an efficient technology for degrading organic pollutants in water, providing an effective solution for protecting water resources and improving environmental quality, and has significant application value. [ABSTRACT FROM AUTHOR]

Reaction mixtures of naturally abundant aldoses and CH nucleophiles allow for the formation of functionalized furan precursors using low temperatures and metal-free catalysis in aqueous solutions of dilute base catalysts. We employ in situ NMR assays to clarify the mechanism and kinetics of the conversion. Catalysis serves a double role in ring-opening of stable aldoses such as glucose and xylose and facilitating the subsequent reactions with CH acids such as malononitrile or cyanoacetamide. Resultant acyclic products are shown to convert quickly to a monocyclic product prior to the slower formation of a more stable bicyclic intermediate and dehydration to tri-functionalized furan. Especially the reversible 5-exo-dig ring closure entailing oxygen attack onto a nitrile carbon is surprisingly fast with an equilibrium vastly towards the cyclic state, sequestering reactive groups and allowing the selective conversion to tri-functionalized furan. The reaction hinges on the fast formation of intermediates without CH acidity and competes with the oligomerization of CH nucleophiles. Insight derived from in situ NMR analysis shows the prowess of high-resolution in situ spectroscopy in clarifying the interplay between catalysts and reactants. Such insight will be vital for the optimization of reactions that upgrade biorenewables under benign conditions. [ABSTRACT FROM AUTHOR]

To develop and design highly efficient composite oxide nanoparticles for the combustion of chlorinated volatile organic compounds (CVOCs), a series of Co3O4/In2O3 catalysts were synthesized and tested for the catalytic oxidation of chlorobenzene (CB) as a typical example for CVOCs. The catalytic performance of as-prepared samples manifested that InxCo1Oy nanorods catalysts with an appropriate proportion of In/Co exhibited superior catalytic activity better than that of pure Co3O4 nanorods, indicating that the strong interactions between cobalt oxide and indium oxide assisted the degradation of CB. To understand the synergistic mechanism, a series of experimental characterization have been employed to explore the physicochemical properties of the catalysts. The result indicates that the introduction of In2O3 increases the Co3+ contents and the mobility of surface oxygen species, which synergistically contribute to the degradation process of chlorobenzene. Furthermore, the intermediates that appeared in the process of CB degradation on the In3Co1Oy catalyst have been monitored by in situ DRIFTS. The detailed reaction mechanism is established by the analysis of the intermediates. [ABSTRACT FROM AUTHOR]

The impact of the active site produced by the active metal V centre on the production of phenol from benzene was deduced from the cluster model structure of VAPO-5. In this work, the mechanism of benzene to phenol under the VAPO-5 model was explored. The transition states, intermediates, and reaction energy barrier throughout the reaction were evaluated by the ONIOM approach, which combines semi-empirical analysis with density functional theory. The outcomes demonstrated that this reaction was divided into four stages, with each stage's energy barriers being 59.9, 122, 204.8, and 60.7 kJ/mol, respectively. And a lower energy barrier of 204.8 kJ/mol must be surpassed to pass the determining speed phase's energy barrier of 296.8 kJ/mol. Additionally, the solvation of acetonitrile was looked into, resulting in the crossing of the energy barrier of 174.8 kJ/mol. [ABSTRACT FROM AUTHOR]

Flavoprotein monooxygenases catalyze reactions, including hydroxylation and epoxidation, involved in the catabolism, detoxification, and biosynthesis of natural substrates and industrial contaminants. Among them, the 6-hydroxy-3-succinoyl-pyridine (HSP) monooxygenase (HspB) from Pseudomonas putida S16 facilitates the hydroxylation and C-C bond cleavage of the pyridine ring in nicotine. However, the mechanism for biodegradation remains elusive. Here, we refined the crystal structure of HspB and elucidated the detailed mechanism behind the oxidative hydroxylation and C-C cleavage processes. Leveraging structural information about domains for binding the cofactor flavin adenine dinucleotide (FAD) and HSP substrate, we used molecular dynamics simulations and quantum/molecular mechanics calculations to demonstrate that the transfer of an oxygen atom from the reactive FAD peroxide species (C4a-hydroperoxyflavin) to the C3 atom in the HSP substrate constitutes a rate-limiting step, with a calculated reaction barrier of about 20 kcal/mol. Subsequently, the hydrogen atom was rebounded to the FAD cofactor, forming C4a-hydroxyflavin. The residue Cys218 then catalyzed the subsequent hydrolytic process of C-C cleavage. Our findings contribute to a deeper understanding of the versatile functions of flavoproteins in the natural transformation of pyridine and HspB in nicotine degradation.IMPORTANCE Pseudomonas putida S16 plays a pivotal role in degrading nicotine, a toxic pyridine derivative that poses significant environmental challenges. This study highlights a key enzyme, HspB (6-hydroxy-3-succinoyl-pyridine monooxygenase), in breaking down nicotine through the pyrrolidine pathway. Utilizing dioxygen and a flavin adenine dinucleotide cofactor, HspB hydroxylates and cleaves the substrate’s side chain. Structural analysis of the refined HspB crystal structure, combined with state-ofthe- art computations, reveals its distinctive mechanism. The crucial function of Cys218 was never discovered in its homologous enzymes. Our findings not only deepen our understanding of bacterial nicotine degradation but also open avenues for applications in both environmental cleanup and pharmaceutical development. [ABSTRACT FROM AUTHOR]

Cyclotrisilenes can pursue four types of reaction pathways with unsaturated substrates: π-addition, σ-insertion, exocyclic σ-insertion, and ring-opening reactions. A computational investigation of all these reaction pathways of 1,2,3,3-tetramethyl cyclotrisilene c-Si3Me4 (I) and 1,2-bis(trimethylsilyl)-3,3-dimethyl cyclotrisilene c-Si3Me2(SiMe3)2 (II) with phenylacetylene (R1) and benzaldehyde (R2) is carried out. The reaction pathways are found to be significantly influenced by the substituents attached to the cyclotrisilene ring. Both the π-addition and the σ-insertion reactions proceed with moderate activation energy and high exoergicity, and the electronic nature of the functional group is crucial in deciding the favorable pathway. The exocyclic σ-insertion reactions are found to possess a huge energy barrier, irrespective of the steric and electronic nature of cyclotrisilenes and the substrates. While the course of the reaction and the viability of the ring-opening reaction with phenylacetylene are impacted by the nature of cyclotrisilene, the ring-opening reactions of I and II with benzaldehyde are both highly endoergic. [ABSTRACT FROM AUTHOR]

Vanadium nitride (VN), as a typical transition metal nitride, has widespread applications in various fields due to its high melting point, high hardness, and excellent thermal and chemical stability. In this study, VN was synthesized through the carbon thermal reduction nitridation method using V 2 O 3 as the main material, and the reaction mechanism was thoroughly examined. Thermodynamic analysis, coupled with thermogravimetry-differential scanning calorimetry (TG-DSC), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD), revealed that the reaction mechanism was not simply a direct nitridation process nor a two-step coupling of reduction and carburization. Instead, it was the result of multiple reaction mechanisms working in conjunction. Direct nitridation of V 2 O 3 occurred throughout the entire reaction process, while indirect nitridation of VO and VC also occurred with the variation of temperature. A kinetic model was constructed based on the material thermal weight loss curve and revealed that in the carbothermal reduction nitridation system of V 2 O 3 , the solid phase reaction followed a three-dimensional diffusion model, with an activation energy of 160.244 kJ/mol, while the gas phase reaction with the solid phase followed a one-dimensional interface model, with an activation energy of 169.015 kJ/mol. [ABSTRACT FROM AUTHOR]

By planting LEDs on the surfaces of orifice baffles, a novel batch oscillatory baffled photoreactor (OBPR) together with polymer-supported Rose Bengal (Ps-RB) beads are here used to investigate the reaction kinetics of a photo-oxidation reaction between α-terpinene and singlet oxygen (1O2). In the mode of NMR data analysis that is widely used for this reaction, α-terpinene and ascaridole are treated as a reaction pair, assuming kinetically singlet oxygen is in excess or constant. We have, for the first time, here examined the validity of the method, discovered that increasing α-terpinene initially leads to an increase in ascaridole, indicating that the supply of singlet oxygen is in excess. Applying a kinetic analysis, a pseudo-first-order reaction kinetics is confirmed, supporting this assumption. We have subsequently initiated a methodology of estimating the 1O2 concentrations based on the proportionality of ascaridole concentrations with respect to its maximum under these conditions. With the help of the estimated singlet oxygen data, the efficiency of 1O2 utilization and the photo efficiency of converting molecular oxygen to 1O2 are further proposed and evaluated. We have also identified conditions under which a further increase in α-terpinene has caused decreases in ascaridole, implying kinetically that 1O2 has now become a limiting reagent, and the method of treating α-terpinene and ascaridole as a reaction pair in the data analysis would no longer be valid under those conditions. [ABSTRACT FROM AUTHOR]

In this study, an electrochemical-assisted ferric ion/persulfate (EC/Fe3+/PS) process was proposed to degrade bezafibrate (BZF), a widespread hypolipidemic drug, in water. By promoting the reduction of Fe3+ to Fe2+ at the cathode, the introduction of an electric field successfully overcomes the limitation of non-regenerable Fe2+ inherent in Fe2+/PS systems, significantly improving the degradation efficiency of BZF. The predominant reactive species identified were •OH and SO4●−, with 1O2 also playing a role. Various key operational parameters were investigated and optimized, including the current intensity, Fe3+ dosage, PS concentration, and initial pH. With a current intensity of 50 mA, an Fe3+ concentration of 50 μΜ, a PS dosage of 50 μM, and an initial pH of 3, the degradation efficiency of BZF demonstrated an exceptional achievement, reaching up to 98.8% within 30 min. The influence of anions and humic acid was also assessed. An LC/TOF/MS analysis revealed four major degradation pathways of BZF: hydroxylation, amino bond cleavage, dechlorination, and fibrate chain removal. The acute and chronic toxicities of BZF and its degradation intermediates were then assessed using the ECOSAR program. These findings highlight the wide-ranging applications of the EC/Fe3+/PS system and its potential for remediating water contaminated with micropollutants. [ABSTRACT FROM AUTHOR]

The surface configurations of the low-index facets of a set of spinel oxides are investigated using DFT+U calculations to derive surface energies and predict equilibrium nanoparticle shapes via the Wulff construction. Two very different conditions are investigated, corresponding to application either in heterogeneous catalysis or in electrocatalysis. First, the bare stoichiometric surfaces of NiFe2O4, CoFe2O4, NiCo2O4, and ZnCo2O4 spinels are studied to model their use as high-temperature oxidation catalysts. Second, focusing attention on the electrochemical oxygen evolution reaction (OER) and on the CoFe2O4 inverse spinel as the most promising OER catalyst, we generate surface configurations by adsorbing OER intermediates and, in an innovative study, we recalculate surface energies taking into account adsorption and environmental conditions, i.e., applied electrode potential and O2 pressure. We predict that under OER operating conditions, (111) facets are dominant in CoFe2O4 nanoparticle shapes, in fair agreement with microscopy measurements. Importantly, in the OER case, we predict a strong dependence of nanoparticle shape upon O2 pressure. Increasing O2 pressure increases the size of the higher-index (111) and (110) facets at the expense of the (001) more catalytically active facet, whereas the opposite occurs at low O2 pressure. These predictions should be experimentally verifiable and help define the optimal OER operative conditions. [ABSTRACT FROM AUTHOR]

Oxygenates production from the partial oxidation of liquid fuel is required for a cleaner combustion. The effect of Mn/Fe ratio was investigated to improve the oxygenates formation via plasma catalytic n-C5H12 partial oxidation over FeMn/Al2O3 catalyst. The oxygenates selectivities exhibited a volcano shape with the Mn/Fe ratio and the highest value of 69% was obtained at Mn/Fe ratio of 7/3. The oxygenates selectivities were dominated by both the acidity and active oxygen species of catalyst, which could be tuned by Mn/Fe ratio. A close relationship between oxygenates selectivities, acidity, and active oxygen species of catalyst was established. The higher the active oxygen species content and the lower the acidity, the higher the oxygenates selectivities. [ABSTRACT FROM AUTHOR]

Chalcogenide perovskites are receiving considerable attention as a new type of semiconducting material for optoelectronic applications. The current work is carried out on optimization studies for depositing SrZrS3 perovskite thin films via chemical bath deposition. The film properties were investigated as a function of molar concentration ratios (0.4–0.6 M), complexing agent, pH (9–10), deposition time (14–20 h), and annealing temperature (300–500°C). The orthorhombic structure of the deposited thin film was verified by x-ray diffraction (XRD) investigation. The Pnma space group was identified by XRD investigations with lattice constants of 7.09 Å, 9.77 Å, and 6.78 Å. The optical characteristics of the films were examined using a UV–Vis spectrophotometer. Bandgap values in the range of 3.34–3.50 eV, and absorption coefficient 1.75 × 104 cm−1 to 2.15 × 104 cm−1 were observed for the synthesized samples. It was found that 500°C for the annealing temperature and a pH of 10 were the optimal values for the SrZrS3 thin film deposition parameters. [ABSTRACT FROM AUTHOR]

Abstract Copper‐catalyzed C─H oxygenation has drawn considerable attention in mechanistic studies. However, a comprehensive investigation combining radical pathways with a metal‐catalytic cycle is challenged by the intricate organic radicals and metallic intermediates. Herein, an online coupled EPR/UV–vis/near‐IR detecting method is developed to simultaneously monitor both reactive radical species and copper complex intermediates during the reaction. Focusing on copper‐catalyzed phenol oxygenation with cumene hydroperoxide, the short‐lived alkylperoxyl radical (EPR signal at g = 2.0143) as well as the unexpected square planar Cu(II)‐alkoxyl radical complex (near‐IR signal at 833 nm) are unveiled during the reaction, in addition to the observable phenoxyl radical in EPR, quinone product in UV–vis, and Cu(II) center in EPR. With a comprehensive picture of diverse intermediates evolving over the same timeline, a novel Cu(I)/Cu(II) proposed relay‐catalyzed sequential radical pathway. In this sequence, Cu(II) activates hydroperoxide through Cu(II)‐OOR into the alkylperoxide radical, while the reaction between Cu(I) and hydroperoxide leads to Cu(II)(•OR)OH with high H‐atom abstracting activity. These results provide a thorough understanding of the Cu(I)/Cu(II) relay catalysis for phenol oxygenation, setting the stage for mechanistic investigations into intricate radical reactions promoted by metallic complexes.

Abstract The acyltransferase from Pseudomonas protegens (PpATase) catalyzes in nature the reversible transformation of monoacetylphloroglucinol to diacetylphloroglucinol and phloroglucinol. Interestingly, this enzyme has been shown to catalyze the promiscuous transformation of 3‐hydroxyphenyl acetate to 2′,4′‐dihydroxyacetophenone, representing a biological version of the Fries rearrangement. In the present study, we report a mechanistic investigation of this activity of PpATase using quantum chemical calculations. A detailed mechanism is proposed, and the energy profile for the reaction is presented. The calculations show that the acylation of the enzyme is highly exothermic, while the acetyl transfer back to the substrate is only slightly exothermic. The deprotonation of the C6−H of the substrate is rate‐limiting, and a remote aspartate residue (Asp137) is proposed to be the general base group in this step. Analysis of the binding energies of various acetyl acceptors shows that PpATase can promote both intramolecular and intermolecular Fries rearrangement towards diverse compounds.

Cytosine is an essential chemical molecule in living systems, such as DNA and RNA, it is essential in astrobiology to study how it behaves under probable primitive conditions. We looked at how cytosine broke down in aqueous solutions exposed to high radiation levels to learn more about how stable it might have been on the early Earth. We conducted various types of analysis, such as ultraviolet–visible spectroscopy and high-pressure liquid chromatography. We also developed a computer model to describe the kinetic processes and learn more about the molecules involved in the system. This model fits the results of experiments and lets us study cytosine's stability when it is exposed to gamma radiation. It enables researchers to theorize processes that are hard to test in the laboratory and is essential for studying how stable cytosine behaves in high-radiation settings.

The crystalline agents can be used to improve the concrete frost resistance by its densification effect on the microstructure of concrete, while the effect of which depends on the type and penetration process of the crystalline agents. This study, therefore, aimed to investigate the effect of two types of crystalline materials, in terms of organic and inorganic one, and two kinds of penetration methods including surface coating and soaking, in concrete. In addition to freeze-thaw test and electric flux test, the thermal gravity analysis, mercury intrusion porosimetry and scanning electron microscope were carried out. The results showed that after vacuum drying and soaking treatment, the material’s penetration depth has reached 7 mm. Deeper penetration depth shifted the freeze-thaw failure mode sudden to gradual, significantly enhancing frost resistance as a result. Among them, organic crystalline agent increased frost resistance by 2.5 times and decreased electrical flux by approximately 90 %, while inorganic crystalline agent only enhanced frost resistance by 1.5 times and reduced electrical flux by only about 37 %. From a reaction mechanism perspective, the hydrophobic layer within the pores formed by organic crystalline material has the most contribution, in which the needle-like substances generated by inorganic one filled the pores with limited effect to barrier water.

The electrode is a core component that affects the overall performance of the hydrogen/iron redox flow battery. To address the drawbacks associated with the limited electrochemical activity and fewer active sites of the carbon-based electrode, this study employs a straightforward and effective flame method to synthesize carbon nanotubes (CNTs) on carbon paper and NiO/CNT composite on graphite felt. The CNT on the modified carbon-based electrode contains many hydrophilic and oxygen-containing functional groups, greatly improving the hydrophilicity of the electrode, thereby increasing the electrochemical surface area. The modified carbon-based electrode exhibits better electrochemical activity due to the CNT or NiO/CNT providing more active sites. At 50 mA cm−2, the energy efficiency of pristine carbon paper and graphite felt is 60.8% and 52.4%, respectively, while the energy efficiency of the modified carbon paper and graphite felt reached 75.3% and 80.5%, respectively. The modified carbon-based electrode achieves a 100% coulombic efficiency, with no significant degradation in energy efficiency after running for 300 cycles, demonstrating excellent stability. This study not only investigates the performance of graphite felt electrodes in hydrogen/iron batteries but also proposes a flame method for preparing CNT-modified carbon-based electrodes for high-performance hydrogen/iron batteries.

Cancer is one of the deadliest diseases in the world. Currently, there are various types of anticancer drugs that are used to treat cancer, but they still have various side effects that can interfere with the quality of life of patients. Organometallic complexes (OCOs) are chemical compounds consisting of metal atoms bonded to carbon atoms. OCOs have various potential to be used as anticancer drugs, including their ability to specifically target cancer cells, inhibit cancer cell growth, and reduce the side effects of other anticancer drugs. The mechanism of action of OCOs involves interactions with nucleophilic molecules within the cell, including DNA, RNA, and proteins, as well as the formation of additional platinum products. In this review, we will discuss organometallic compounds that can function as anticancer drugs, such as platinum, ruthenium, iron, carboplatin, and oxaliplatin, which have been shown to be effective in fighting cancer. We will also discuss the mechanism of action of these compounds in cancer cells and the types of cancer cells that can be treated with organometallic compounds.

Biomass has supplanted traditional fuels as the principal renewable energy source due to its carbon neutrality. Because of its high viscosity, thermal instability, and undesired coke production, biomass oil has limited applicability; however, hydro-treatment procedures can address these drawbacks and produce bio-oil fuels that meet industry standards. Consequently, compounds containing hydroxyl entities, especially oxygenated aromatics, are treated using the hydro-deoxygenation (HDO) process. Deoxygenation has seen the rise of effective transition metal-supported catalysts, both noble and non-noble, which have impeded the usage of traditional sulfided catalysts. Nevertheless, there are a number of reports in the literature of successful HDO processes using sulfided catalysts. As a model material for waste biomass, date pits were deoxygenated using 10 % Co–MoS2 produced via incipient wet impregnation in this study. The catalyst had a specific surface area of 15 m2/g, as proven by the nitrogen adsorption/desorption technique, the most essential analysis. Additionally, the catalyst was analyzed using XRD, SEM-EDX, HRTEM, and FTIR (for both the biomass deoxygenated products and the catalyst). The date pit pyrolysates were subjected to temperatures ranging from 100 to 500 °C in a 2-stage catalytic reactor for HDO. At 300 °C, 400 °C, and 500 °C, the condensable and non-condensable fractions could be identified. Deoxygenated aromatics were initially detected at 400 °C, with a complete conversion to benzene derivatives occurring at 500 °C, in contrast to the furanic products, which were primarily prevalent at 300 °C. At 18.12 % for the condensable fraction and 30.70 % for the non-condensable fraction, toluene had the highest relative area. Various oxygenated aromatic HDO reaction routes leading to toluene production were covered. The findings presented here opens the door to the potential widespread usage of Co–MoS2 in HDO processes with actual biomass fuels.

Metal (aluminum and boron) based energetic materials have been wildly applied in various fields including aerospace, explosives and micro-devices due to their high energy density. Unfortunately, the low combustion efficiency and reactivity of metal fuels, especially boron (B), severely limit their practical applications. Herein, multi-component 3D microspheres of HMX/B/Al/PTFE (HBA) have been designed and successfully prepared by emulsion and solvent evaporation method to achieve superior energy and combustion reactivity. The reactivity and energy output of HBA are systematically measured by ignition-burning test, constant-volume explosion vessel system and bomb calorimetry. Due to the increased interfacial contact and reaction area, HBA shows higher flame propagation rate, faster pressurization rate and larger combustion heat of 29.95 cm/s, 1077 kPa/s, and 6164.43 J/g, which is 1.5 times, 3.5 times, and 1.03 times of the physical mixed counterpart (HBA-P). Meanwhile, HBA also shows enhanced energy output and reactivity than 3D microspheres of HMX/B/PTFE (HB) resulting from the high reactivity of Al. The reaction mechanism of 3D microspheres is comprehensively investigated through combustion emission spectral and thermal analysis (TG-DSC-MS). The superior reactivity and energy of HBA originate from the surface etching of fluorine to the inert shell (Al2O3 and B2O3) and the initiation effect of Al to B. This work offers a promising approach to design and prepare high-performance energetic materials for the practical applications.

Photocatalysis driven by abundant yet intermittent solar energy has considerable potential in renewable energy generation and environmental remediation. The outstanding electronic structure and physicochemical properties of graphitic carbon nitride (g-C3N4), together with unique metal-free characteristic, make them ideal candidates for advanced photocatalysts construction. This review summarizes the up-to-date advances on g-C3N4 based photocatalysts from ingenious-design strategies and diversified photocatalytic applications. Notably, the advantages, fabrication methods and limitations of each design strategy are systemically analyzed. In order to deeply comprehend the inner connection of theory–structure–performance upon g-C3N4 based photocatalysts, structure/composition designs, corresponding photocatalytic activities and reaction mechanisms are jointly discussed, associated with introducing their photocatalytic applications toward water splitting, carbon dioxide/nitrogen reduction and pollutants degradation, etc. Finally, the current challenges and future perspectives for g-C3N4 based materials for photocatalysis are briefly proposed. These design strategies and limitations are also instructive for constructing g-C3N4 based materials in other energy and environment-related applications.

The surface configurations of the low-index facets of a set of spinel oxides are investigated using DFT+U calculations to derive surface energies and predict equilibrium nanoparticle shapes via the Wulff construction. Two very different conditions are investigated, corresponding to application either in heterogeneous catalysis or in electrocatalysis. First, the bare stoichiometric surfaces of NiFe2O4, CoFe2O4, NiCo2O4, and ZnCo2O4 spinels are studied to model their use as high-temperature oxidation catalysts. Second, focusing attention on the electrochemical oxygen evolution reaction (OER) and on the CoFe2O4 inverse spinel as the most promising OER catalyst, we generate surface configurations by adsorbing OER intermediates and, in an innovative study, we recalculate surface energies taking into account adsorption and environmental conditions, i.e., applied electrode potential and O2 pressure. We predict that under OER operating conditions, (111) facets are dominant in CoFe2O4 nanoparticle shapes, in fair agreement with microscopy measurements. Importantly, in the OER case, we predict a strong dependence of nanoparticle shape upon O2 pressure. Increasing O2 pressure increases the size of the higher-index (111) and (110) facets at the expense of the (001) more catalytically active facet, whereas the opposite occurs at low O2 pressure. These predictions should be experimentally verifiable and help define the optimal OER operative conditions.

Highlights The hierarchical nanogrid-in-nanofiber-structured dual-type carbon-confined CoTe2 nanodots (CoTe2@NC@NSPCNFs) were synthesized via facile templates and an electrospinning approach. Hierarchical nanogrid-in-nanofiber structure effectively suppresses the volume change of CoTe2 and the shuttle of potassium polytelluride (K-pTe x ) through robust physical restraint and strong chemisorption. CoTe2@NC@NSPCNFs hybrid achieves ultralong lifespan potassium-storage performance over 3500 cycles, and the deep mechanisms underlying the evolution, dissolution, and shuttle of K-pTe x have been clearly revealed.