Search

The aza-Michael addition reaction of primary and secondary amines to α,β-unsaturated olefins viz; acrylonitrile, phenyl vinyl sulfone and dimethyl maleate has been carried out using 5–10 mol% Co(NO3)2.6H2O as a catalyst in t-BuOMe at 80–100 °C, giving rise to the desired β-aminocarbonyl compounds or sulfones in moderate to good yields. A wide range of aromatic amines, even those bearing electron withdrawing groups could be added to activated olefins via this strategy. Addition of (hetero)aromatic amines were also feasible, while in case of 2-aminopyridine the reaction was found to be effective only when AgOTf was added along with the catalyst. The aliphatic amines; benzylamine, dibenzylamine, di-n-butylamine were also smoothly added to acrylonitrile and phenyl vinyl sulfone. The methodology describes cobalt(II) nitrate as an eco-friendly, cheap and shelf available catalyst suitable for performing the Michael-type hydroamination reactions. [ABSTRACT FROM AUTHOR]

Various advanced sources have been developed to cope with the exponential need for world energies, such as hydrogen production, photovoltaic solar cells, lithium batteries and fuel cells, etc. Among these, fuel cells are better owing to their power production, renewability, and green natural technology. In fuel cells, chemical energy is converted into electrical energy with the help of an electrochemical device, having three major components, i.e. electrodes, electrolytes and catalysts. Bismuth-based materials would be a good choice to develop an efficient fuel cell and can be used as electrodes, electrolytes, and catalysts. Bi2SiO5@NG(NG = nitrogen-doped graphene) is a Bi-based nano-composite used as a cathodic catalyst to enhance the oxygen reduction reaction (ORR). Co−Bi@rGO (rGO = reduced graphene oxide) is used as an anode for an EtOH fuel cell due to its low cost and high efficiency. Bi-based solid oxide electrolytes, e.g. sulfonated poly(ether, ketone) (SPEEK) polymer having 7.5 wt.% of bismuth cobalt zinc oxide (BCZO) with a high-power density of 574 mW cm−2 have been reported in this regard. These factors accentuate the relevance of bismuth-based materials for the production of components for fuel cells that have excellent performance. This review examines the published literature on bismuth-based materials and anticipates the synthesis, and role of material in fuel cells. Finally, current challenges and future perspectives present comprehensive guidelines for future research. [ABSTRACT FROM AUTHOR]

HPSB (Hydrolysis Product of Sodium Borohydride) hydrogen storage material is a kind of porous lamellar structural material developed by our research group. Due to the special structure of this material, it can absorb hydrogen at room temperature, hydrogen absorption pressure is 2–4 MPa, and hydrogen absorption time is 2–5 min. The main preparation method used in the experiment is hydrolysis. The main raw material is sodium borohydride, and the reaction temperature is 30 °C. In this experiment, in order to improve the hydrogen storage performance of HPSB hydrogen storage material, Co–B and Sm 2 O 3 were introduced as catalysts during the preparation of HPSB. The results show that the amount of Sm 2 O 3 and the ratio of Sm 2 O 3 to Co–B have obvious influence on the hydrogen storage performance of HPSB. In addition, according to the results of SEM analysis, the amount of Sm 2 O 3 and the ratio of Sm 2 O 3 to Co–B also have obvious effects on the microstructure of HPSB hydrogen storage materials. The sample with a doping amount of 4 wt% and a ratio of Sm 2 O 3 to Co–B of 4:6 can release 2.17 wt% H 2. • The catalyst Co–B/Sm 2 O 3 can improve the hydrogen storage performance of HPSB. • Co–B/Sm 2 O 3 doping 4 wt% and ratio 4:6 shows the best dehydrogenation performance. • The maximum total dehydrogenation amount of the Co–B/Sm 2 O 3 doped sample is 2.17 wt%. [ABSTRACT FROM AUTHOR]

This paper is focused on the solution combustion synthesis (SCS) of a set of 90Ni/10Al 2 O 3 (wt. %) catalysts for the production of hydrogen and carbon nanofibers through methane decomposition. A novel approach was employed to optimize the SCS of the catalysts in order to enhance the yields of hydrogen. The obtained catalysts were tested in methane decomposition at 550 °C and 1 bar. Transmission electron microscopy, energy-dispersive X-ray spectroscopy, low temperature nitrogen adsorption, and X-ray diffraction were utilized to investigate the catalysts. The SCS process involved programmable heating of a mixture of Ni(NO 3) 2 ·6H 2 O and Al(NO 3) 3 ·9H 2 O with citric acid (C 6 H 8 O 7) from room temperature to 350–450 °C at a heating rates 1–10 °C/min and exposure durations of 0–20 min. It was discovered that a high specific yield of hydrogen (17.1 mol/g cat.) and carbon nanofibers (171 g/g cat.) can be achieved by synthesizing at 450 °C using a heating rate of 1 °C/min without additional exposure. • Decomposition of CH 4 using Ni/Al 2 O 3 catalysts was analyzed. • Regression analysis of solution combustion synthesis (SCS) was carried out. • Mechanisms of formation of catalytic nanoparticles were investigated. • The effect of fuel-to-oxidizer ratio is dominant for the SCS of Ni/Al 2 O 3 catalyst. • Improved catalytic properties for production of hydrogen and carbon were shown. [ABSTRACT FROM AUTHOR]

Producing hydrogen (H2) from biomass gasification offers exceptional benefits regarding renewable energy sources, zero‐carbon emission, cost‐effective processes, and high efficiency. The addition of catalysts to biomass gasification could accelerate the process and minimize the formation of coke. However, the catalyst deactivation caused by carbon deposition, poisoning, and sintering is still a significant problem in the gasification process. Therefore, achieving sustainable exploitation of the renewable natural resource of biomass requires substantial development and optimization of the present gasification process. The efficiency of gasification might decrease because of such a process. In this study, CeO2(111) is chosen to investigate the analysis of adsorption molecules during catalytic gasification using the density functional theory method. Three catalyst models, CeO2(111), Zr‐CeO2(111), and Ni‐CeO2(111), have been studied in this work in terms of structural, electronic, and adsorption molecule properties. The structural and electronic properties of the modified catalyst model show the ligand and strain effect on the alloy, with the addition of Zr and Ni as second metals promoting the adsorption capability. Searching for active sites is also carried out by adsorption of selected atoms and molecules and used as a preliminary study to find possible active sites for gasification reactions. The Zr‐CeO2(111) and Ni‐CeO2 catalysts exhibit better adsorption ability on atomics and molecules. The Zr and Ni metals are suitable second metal candidates for the catalyst to proceed with the gasification reaction and simultaneously reduce carbon deposition, poisoning, and sintering problems. [ABSTRACT FROM AUTHOR]

The innovation of high‐performance, stable electrocatalysts for clean energy systems faces significant challenges. Metal‐organic frameworks (MOFs), with their porous nature, flexible structures, and homogeneous active site dispersion, have gained interest as unique precursors for carbon‐based catalysts. MOFs' properties significantly enhance catalytic performance in fuel cells. This review highlights recent advancements in MOF design for oxygen electrocatalysis in fuel cells, while also discussing perspectives for future material innovations to improve catalytic activity in this emerging field. [ABSTRACT FROM AUTHOR]

BACKGROUND: The transesterification of butteroil has been shown to alter its lipid chemistry and thus alter the crystallization of the fat. The reaction kinetics and resulting crystallization of the butteroil differ depending on the nature of the catalyst used. Modeling the reaction with vegetable oils is a simpler method for the analysis of resulting products to understand the chemical and physiochemical changes that occur based on catalyst selection. The objective of this work is to perform a chemical transesterification of coconut and corn oil using monovalent and divalent catalysts to investigate the chemical and crystal changes that occur. RESULTS: Coconut and corn oil were subjected to chemical transesterification using both Ca(OH)2 and KOH as catalysts. In both the coconut and corn oil samples, transesterification caused monoglycerides (MAGs) and diacylglycerides (DAGs) to form from the most abundant fatty acid found in each sample. Coconut oil's melting temperature, solid fat content (SFC), and storage modulus decreased as a result of the transesterification, and crystals began to form in the corn oil causing melting thermograms to be evident, higher SFC, and a more viscous oil as a result. Using Ca(OH)2 as a catalyst resulted in more MAG formation, and a higher SFC and melting temperature than when KOH was used as a catalyst. CONCLUSION: The results demonstrate that the chemical changes that result from transesterification of plant‐based oils change the crystallization behavior of the oils and can therefore be used for different applications in the food industry. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Nonthermal plasma (NTP) is an efficient treatment technology for cooking fumes (CFs). However, its practical implementation is hindered due to the low mineralization rate of CFs and high generation of by-products. In this study, a hybrid system coupling NTP and Mn/HZSM-5 catalysts was developed for the deep oxidation of CFs. These catalysts exhibited a remarkable synergistic effect together with NTP in improving the efficiency of CFs removal. When the specific energy density was 282 J·L− 1, the hybrid system had stable reactivity, and the CFs removal efficiency and CO2 yield were 100% and 78.4%, respectively, which were 10% and 61% higher than the values achieved with the NTP system alone. The Mn/HZSM-5 catalysts were also discovered to inhibit the production of O3 and NO2 to a large extent and to achieve a removal efficiency level at > 80%. The Mn/HZSM-5 catalysts' high Mn4+/Mn ratio and the relatively large amount of chemisorbed oxygen on the catalyst surface engendered their remarkable performance. On the basis of the detected active species and organic products, the reaction mechanism governing the destruction of CFs by the NTP-Mn/HZSM-5 catalyst system was also discussed. [ABSTRACT FROM AUTHOR]

A significant and sustainable feedstock for many value added products is levulinic acid, which is basically a short‐chain fatty acid. The current study aims to comprehend how multiple factors affect the hydrothermal reactions that convert glucose to levulinic acid. Glucose can be readily obtained from lignocellulosic biomass and hence it is selected in the work as representative sustainable source. The effect of various operating parameters, including time (0–180 min), temperature (140–180°C), nitrogen pressure (0–25 bar), glucose concentration (3%–10%), agitation speed (100–300 RPM), and acid concentration (2%–6%); use of different salts (NaCl, AlCl3 6H2O, FeCl3); and different acids (HCl, H3PO4, H2SO4) on the reaction progress has been studied in a batch autoclave reactor. It was elucidated that pressure (only nitrogen purge was essential for reaction progress) or salt content changes did not affect sugar conversion significantly. The process was seriously influenced by the presence of acids, mostly in the form of homogeneous catalysts, and the most significant results were obtained for H2SO4. The highest levulinic acid yield (39.7 g/g) at 90 min, with nearly complete sugar conversion, was obtained under the ideal conditions of 160°C, 5% sugar loading, and 5% H2SO4 concentration. The current study indicates that the two primary operating parameters in this conversion process are temperature and time, with higher temperature and lower sugar concentration showing a rising tendency in sugar conversion. Overall, the study establishes a sustainable process for levulinic acid synthesis. [ABSTRACT FROM AUTHOR]

Fuel cells are promising fossil fuel alternatives that are both environmentally friendly and powerful. Direct methanol fuel cells are particularly suitable for lightweight cars and portable electronics. Developing efficient, cost-effective, and eco-friendly catalysts for energy storage and conversion devices is vital for long-term energy security. Numerous studies have explored using metal oxides and modifications to mixed transition metal oxide (MTMO)-based catalysts to enhance the methanol oxidation process. Coupling transition metals (Mn, Co, Ni, Fe, Zn, etc.) in MTMOs improves redox processes and electronic conductivity, advancing electrochemical applications. Among these, nickel cobaltite (NiCo₂O₄) stands out due to its material stability and higher electronic conductivity compared to single-component metal oxides NiO and Co₃O₄. NiCo₂O₄ shows great potential as a composite-based material for fuel cell applications. This paper reviews studies on NiCo₂O₄ as composite-based materials for electrocatalysts, including various methods for synthesizing nanostructures suitable for direct methanol fuel cells. It also highlights the challenges and potential benefits of using NiCo₂O₄ in practical energy storage systems, offering valuable perspectives and insights for early-stage researchers focused on future research and development in composite-based materials for energy applications. [ABSTRACT FROM AUTHOR]

Abstract\nNOVELTY STATEMENTThe synthesis of catalysts has gained specific concern due to their versatile applications in particular azo dye decolorization. In the current work, metallic nanoparticles (copper and silver) were In-situ biosynthesised using Allium sativum and Chondrilla juncea extract. The obtained Allium-copper oxide and Allium-silver oxide materials were analyzed using SEM, TEM, FT-IR, TGA-DTG, SEM, TEM, and XRD techniques. Allium peels had a rough surface, with nanoparticles equally distributed over it. The crystal structure of Allium peels was altered after the addition of CuO and AgO nanoparticles. The highest residual mass values in the prepared materials indicated that the metallic nanoparticles were, in situ, formed. The prepared materials had worse thermal stability than Allium peel powders. The azo dyes, Calmagite and Naphthol Blue Black B were tested in the catalytic power of the resulting materials. The decolorization process was affected by the dye structure, amount of H2O2, dye concentration, time of reaction, and temperature of the bath. The activation energy values for Allium-CuO were 18.44 kJ mol−1 for calmagite, and 23.28 kJ mol−1 for naphthol blue black, respectively. Nevertheless, the energy values for Allium-AgO were 50.01 kJ mol−1 for calmagite and 12.44 kJ mol−1 for Naphthol blue black. The calculated low energy values for the prepared materials suggested the high efficiency of the use of these catalysts in azo dye decolorization under the change of some main experimental conditions.Chondrilla juncea was employed as a biological extract for in-situ reduction of copper and silver ions within Allium sativum peels. The resulting Allium sativum-CuO and Allium sativum -AgO materials were used as efficient catalysts for azo dye decolorization. [ABSTRACT FROM AUTHOR]

In this study, we report that pectin‐supported ruthenium nanoparticles (pectin@Ru0) can be easily prepared at room temperature by a simple and effective method and that they exhibit outstanding catalytic activity in the hydrolysis of sodium borohydride (NaBH4). The structure, oxidation state, morphology, and thermal studies were analyzed using XRD, XPS, SEM, TEM and TGA analysis. The kinetic performance of pectin@Ru0 biocatalyst was evaluated depending on ruthenium loading, NaBH4 concentration, NaOH concentration, temperature, reusability and storage. The pectin@Ru0 biocatalyst containing 2 wt.% Ru0 metal catalyzed the hydrolysis of 50 mM NaBH4+1 wt.% NaOH with 100 % yield. The activation energy (Ea) and the TOF values of the reaction was estimated as 54.7 kJ mol−1 and 53.1 mol H2 (mol Ru0 min) −1 at 30 °C and this is consistent with other previously reported catalysts, making it a remarkable result in comparison. Reusability and catalytic life studies reported that pectin@Ru0 biocatalyst is also highly active and relatively long‐lived catalyst in the hydrolysis of NaBH4 in a slightly basic solution. [ABSTRACT FROM AUTHOR]

Metal/MXene‐based materials show broad prospects in energy conversation through the strong metal‐support interaction (SMSI). However, the difficulty and harshness of synthesis heavily limit their further application. Herein, using Lewis acidic molten salt to etch MAX as a precursor of MXene, a more convenient and safer strategy is designed to in situ construct the MXene‐supported CoIr nanoalloy (CoIr/MXene) catalyst through Ti─O─M bond. The special layered structure and oxygen‐containing functional group of MXene regulate the SMSI upon CoIr nanoalloys. Moreover, the contact angle and in situ Raman test results exhibit good interface hydrophilicity of MXene, enhancing the water adsorption on interfaces, and accelerating the mass transfer process. As a result, CoIr/MXene shows high hydrogen evolution reaction (HER) performance, which only needs overpotentials of 34 and 50 mV to drive a current density of 10 mA cm−2 in alkaline and acidic media, respectively, with excellent stability. Especially, in alkaline media, CoIr/MXene possesses 6 times higher HER mass activity (4.297 A mgIr−1) than commercial Pt/C catalysts (0.686 A mgPt−1) at the potential of 50 mV, indicating larger active site density and intrinsic activity for CoIr/MXene. This work expands the application of the molten salt assist etching strategy and provides new insight for the development of metal/MXene‐based catalysts. [ABSTRACT FROM AUTHOR]

Copyright of Corrosion & Protection in Petrochemical Industry is the property of Corrosion & Protection in Petrochemical 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.)

This study evaluates the potential of several biomasses differing in nature and composition for their valorization by pyrolysis and in line oxidative steam reforming. The first task involved the fast pyrolysis of the biomasses in a conical spouted bed reactor (CSBR) at 500 °C, in which product yields were analyzed in detail. Then, the oxidative steam reforming (OSR) of pyrolysis volatiles (gases and bio‐oil) was approached in a fluidized bed reactor (FBR). The reforming experiments were performed at 600 °C, with a steam/biomass (S/B) ratio of 3 and catalyst (Ni/Al2O3) space times of 7.5 and 20 gcat min gvol−1. Concerning equivalence ratio (ER), a value of 0.12 was selected to ensure autothermal operation. Remarkable differences were observed in H2 production depending on the type of biomass. Thus, pine wood led to a H2 production of 9.3 wt %. The lower productions obtained with rice husk (7.7 wt %) and orange peel (5.5 wt %) are associated with their higher ash and fixed carbon content, respectively, which limit the efficiency of biomass conversion to bio‐oil. However, in the case of the microalgae, the poor performance observed is because of the lower conversion in the reforming step toward gases due to the composition of its pyrolysis volatile stream. [ABSTRACT FROM AUTHOR]

The intensive use of fossil fuels has profound impacts on all ecosystems, primarily contributing to global warming through greenhouse gas emissions. To mitigate these impacts, alternative energy sources like hydrogen are crucial. In this study, azo cross‐linked polymer with 4‐aminophenyl sulfone and resorcinol were synthesized by a green synthesis method. The polymer was extensively characterized by Fourier‐transform infrared spectroscopy, Brunner‐Emmett‐Teller analysis, thermogravimetric analysis, and scanning electron microscopy‐energy dispersive x‐ray spectroscopy analyses. Subsequently, the catalytic performance of the polymer in hydrogen production from NaBH4 via methanolysis was investigated. At this stage, the parameters affecting hydrogen production (catalyst and NaBH4 amounts, MeOH volume and temperature) were systematically studied to determine optimum conditions. The maximum HGR values of the polymer was 13,100 and 27,000 mL min−1 gcat−1 at 30 and 60°C, respectively and its activation energy was 10.45 kJ mol−1. After optimization, the reusability of azo polymer was tested with 5 cycles. The theoretical volume of hydrogen was produced in all 5 cycles. But with each cycle, the hydrogen production time increased. The main purpose of this study was to demonstrate novel azo‐linked polymers with high catalytic activity in hydrogen production. The results revealed significant potential of the polymer for hydrogen generation. Overall, this research highlights the promising role of azo cross‐linked polymers as effective catalysts for hydrogen production, offering new perspectives and pathways towards sustainable energy solutions. [ABSTRACT FROM AUTHOR]

The performance of high‐energy‐density lithium–sulfur (Li–S) batteries is limited by the unmanageable deposition/dissolution kinetics of lithium anode and sulfur cathode, leading to subpar electrochemical efficiency. Prior to being deposited on the electrolyte/electrode interface or within the interior, the solvated lithium‐ion (Li+) must undergo de‐solvation to produce free Li+ ions. These ions then participate in subsequent Redox reactions. The sulfur cathode faces challenges related to solid–liquid transformation and polysulfide conversion/shuttle, which impact the deposition/dissolution process. These issues collectively create insurmountable electrochemical barriers in lithium–sulfur batteries. Atom‐level 2D catalysts, contributing to the consummate atomic efficiency (≈100 at%), play an important role in accelerating deposition/dissolution kinetics in lithium–sulfur batteries. In the review, the preparation of atom‐level 2D catalysts and catalytic kinetic process on accelerating Li+ de‐solvation, Li0 stripping/dissolution, Li0 nucleation/deposition of lithium anode, polysulfide conversion, and LixS deposition of sulfur cathode are summarized, and the outlook of high‐performance single‐atom, multiple atoms modified 2D catalysts in lithium, sodium, and zinc‐based batteries is putting forward. [ABSTRACT FROM AUTHOR]

Efficient and cost-effective catalysts for hydrogen evolution reaction (HER) are essential for large-scale hydrogen production, which is a critical step toward reducing carbon emissions and advancing the global transition to sustainable energy. Nickel sulfide-based catalysts, which exist in various stoichiometries, show promise for HER in alkaline media. However, as single-phase materials, they do not demonstrate superior activity compared to Pt-based catalysts. This review highlights recent strategies to enhance the HER performance of nickel sulfides, including heteroatom doping, heterostructure construction, and vacancy engineering, tailored to their different stoichiometric ratios. The study also examines synthesis methods, characterizations, and their impact on HER performance. Furthermore, it discusses the challenges and limitations of current research and suggests future directions for improvement. [ABSTRACT FROM AUTHOR]

Bimetallic platinum-containing catalysts are deemed promising for electrolyzers and proton-exchange membrane fuel cells (PEMFCs). A significant number of laboratory studies and commercial offers are related to PtNi/C and PtCo/C electrocatalysts. The behavior of PtPd/C catalysts has been studied much less, although palladium itself is the metal closest to platinum in its properties. Using a series of characterization methods, this paper presents a comparative study of structural characteristics of the commercial PtPd/C catalysts containing 38% wt. of precious metals and the well-known HiSpec4000 Pt/C catalyst. The electrochemical behavior of the catalysts was studied both in a three-electrode electrochemical cell and in the membrane electrode assemblies (MEAs) of hydrogen–air PEMFCs. Both PtPd/C samples demonstrated higher values of the electrochemically active surface area, as well as greater specific and mass activity in the oxygen reduction reaction in comparison with conventional Pt/C, while not being inferior to the latter in durability. The MEA based on the best of the PtPd/C catalysts also exhibited higher performance in single tests and long-term durability testing. The results of this study conducted indicate the prospects of using bimetallic PtPd/C materials for cathode catalysts in PEMFCs. [ABSTRACT FROM AUTHOR]

Enlarging the M-Nx active-site density is an effective route to enhance the ORR performance of M-N-C catalysts. In this work, a single-atom catalyst Cu–N@Cu–N–C with enlarged Cu–N4 active site density was prepared by the second doping and pyrolysis (SDP) of Cu–N–C derived from Cu-doped zeolite imidazole frameworks. The half-wave potentials of Cu–N@Cu–N–C were measured as 0.85 V in alkaline electrolyte and 0.75 V in acidic media, which was 50 mV and 60 mV higher than that of Cu–N–C, respectively. N2 adsorption–desorption isotherm curves and corresponding pore distribution analysis were used to verify the successful filling of additional Cu and N in micropores of Cu–N–C after SDP. The obvious increase in Cu contents for Cu–N@Cu–N–C (1.92 wt%) compared with Cu–N–C (0.88 wt%) tested by ICP demonstrated the successful doping of Cu into Cu–N–C. XAFS analysis confirmed the presence of Cu–N4 single-atom active centers in Cu–N@Cu–N–C. The N 1 s high-resolution XPS results proved a great increase in Cu–N4 contents from 13.15% for Cu–N–C to 18.36% for Cu–N@Cu–N–C. The enhanced ORR performance of Cu–N@Cu–N–C was attributed to the enlargement of Cu–N4 active site density, providing an effective route for the preparation of efficient and low-cost ORR catalysts. [ABSTRACT FROM AUTHOR]

The effect of potassium impregnation at different concentrations during gasification, under nitrogen/water steam atmosphere, of char produced via pyrolysis of olive mill residues blended or not with pine sawdust was investigated. Three concentrations (0.1 M, 0.5 M, and 1.5 M) of potassium carbonate solution (K2CO3) were selected to impregnate samples. First, four types of pellets were prepared; one using exhausted olive mill solid waste (G) noted (100G) and three using G blended with pine sawdust (S) in different percentages (50%S–50%G (50S50G); 60%S–40%G (60S40G); 80%S–20%G (80S20G)). Investigations showed that when isothermal temperature increases during the gasification conducted with two water steam percentages of 10% and 30%, the reactivity increases with potassium concentration up to 0.5 M, especially for 100G. Still, higher catalyst concentration (1.5 M) showed adverse effects attributable to silicon release and char pore fouling. Moreover, the effect of the steam concentration on the gasification reactivity was significant with the non-impregnated sample 100G. Finally, a kinetic study was carried out to determine the different kinetic parameters corresponding to the Arrhenius law. [ABSTRACT FROM AUTHOR]

Spent adsorbents for recycling as catalysts have drawn considerable attention due to their environmentally benign chemistry properties. However, traditional thermocatalytic strategies limit their applications. Here, we developed an enhanced photocatalytic strategy to expand the range of their applications. A magnetic chitosan/ZrO2 composites (MZT) for V(V) adsorption, which were prepared using chitosan, ZrO2 and Fe3O4 by one‐pot synthesis. The spent MZT as a catalyst was used to synthesize 2‐phenyl‐1H‐benzo[d]imidazole, yielding up to 89.7 %. It also was implemented to photocatalysis reactions for recycle. The discolored rates of rhodamine B (RhB) were 72.3 % and 97.4 % by new and spent MZT, respectively. The new and spent MZT showed the forbidden bands were 251 nm and 561 nm, respectively. The result displayed spent MZT red shifted to the cyan light region. The mechanism of catalysis also has been studied in detail. [ABSTRACT FROM AUTHOR]

Ammonia borane is widely recognized as a reliable source of hydrogen. However, for efficiently generate hydrogen from ammonia borane, the use of appropriate catalysts is necessary. Transition metal catalysts, significantly enhance the hydrogen production. In our study, we focused on synthesizing a catalyst, Ru-Imine@Al 2 O 3 , by incorporating ruthenium-imine onto the surface of alumina in an ethanoic solution. We conducted this synthesis under ambient conditions. We employed advanced analytical techniques to characterize it. To better understand the structure and composition of catalyst. Notably, this is the first time that Ru-Imine and Ru-Imine@Al 2 O 3 have been used for dehydrogenation of ammonia borane. During our experiments, we found that the Ru-Imine@Al 2 O 3 catalyst exhibited excellent activity in the dehydrogenation process of ammonia borane, releasing hydrogen. We tested different levels of Ru-Imine usage and observed the best performance with 10 % Ru-Imine complex in a 10 mg catalyst. Under these conditions, the catalyst produced 19531 mL H 2 gcat.−1min−1, at 30.0 ± 1 °C. the catalytic activity of 100 % Ru-Imine was also tested under the specified conditions and produced 14183 mL H 2 gcat.−1min−1. To gain further insights into the reaction, we thoroughly determined the kinetics and proposed a mechanism for the dehydrogenation process. Our findings revealed that Ru-Imine@Al 2 O 3 catalyzed dehydrogenation of ammonia borane exhibited a lower activation energy (Ea) of 21.9 kJ mol−1. This implies that the reaction can proceed more easily and efficiently with the presence of the catalyst. Furthermore, we assessed the reusability of the catalyst and found that it demonstrated excellent performance even after eight cycles with 100 % conversion of ammonia borane. This highlights the potential of the Ru-Imine@Al 2 O 3 catalyst for repeated use without significant degradation in its activity. These findings contribute to the advancing of hydrogen generation technologies and offer promising prospects for utilizing ammonia borane as a hydrogen source. [Display omitted] • Ru-Im@Al 2 O 3 catalyst developed to enhance H 2 evolution from NH 3 BH 3 dehydrogenation. • Alumina effect, enhanced the catalytic activity with 19531 mL H 2 g−1 cat.min−1. • Kinetic studies and suggested mechanism were clearly determined for this reaction. • Ru-Im@Al 2 O 3 catalyzed hydrolysis achieved low activation energy of 21.9 kJmol-1. • Ru-Im@Al 2 O 3 displayed high stability of 100 % conversion even after the 8th run. [ABSTRACT FROM AUTHOR]

Redox reactions on the surface of transition metal oxides are of broad interest in thermo, photo, and electrocatalysis. H2 temperature‐programmed reduction (H2‐TPR) is commonly used to probe oxide reducibility by measuring the rate of H2 consumption during temperature ramps, assuming that this rate is controlled by oxide reduction. However, oxide reduction involves several elementary steps, such as H2 dissociation and H‐spillover, before surface reduction and H2O formation occur. In this study, we evaluated the kinetics of H2 consumption over CeO2 and Pt/CeO2 with varying Pt loadings and structures to identify the elementary steps probed by H2‐TPR. Literature often attributes changes in H2‐TPR characteristics with Pt addition to increased CeO2 reducibility. However, our analysis revealed that the H2 consumption rate is measurement of the rate of H‐spillover at Pt‐CeO2 interfaces and is determined by the concentration of Pt species on Pt nanoclusters that dissociate H2. Therefore, lower temperature H2 consumption observed with Pt addition does not indicate higher CeO2 reducibility. Measurements on samples with mixtures of Pt single‐atoms and nanoclusters demonstrated that H2‐TPR can effectively quantify dilute Pt nanocluster concentrations, suggesting caution in directly linking H2‐TPR characteristics to oxide reducibility while highlighting alternative material insights that can be gleaned. [ABSTRACT FROM AUTHOR]

Developing efficient electrooxidation 5‐hydroxymethylfurfural (HMF) catalysts with high selectivity and fast reaction kinetic is challenging. The HMF oxidation reaction (HMFOR) involves the adsorption of HMF and OH− on the catalyst, thus understanding the adsorption behavior between the catalyst surface and reactants is vital. In this work, by studying the relationship between HMFOR performance and the adsorption behavior of reactants on different transition metal oxides (TMOs), it is discovered that the catalytic performance of TMOs is related to the adsorption capacity of OH− and HMF simultaneously. Subsequently, TMOs with different HMF and OH− adsorption abilities are coupled to further optimize the catalytic performance of HMFOR. Experimental and theoretical calculation results indicate that the electronic interactions between different TMOs can regulate the substrate adsorption behavior and electron transfer ability of the catalysts, which is beneficial for HMFOR. Among them, due to the strong interaction between the three components optimizes the adsorption capacity for HMF and OH−, NiO/CuO/Co3O4 exhibits the best HMFOR performance with FDCA selectivity of 99.6 % and formation rate of 16.45 mmol gcat−1 h−1. This work provides a design principle for HMFOR catalysts by modulating the adsorption behavior of reaction molecules. [ABSTRACT FROM AUTHOR]

Surface, interface, and subsurface in catalysts are broadly perceived as independent units in materials, relying on diverse bonding environments and are recurrently studied discretely because of experimental challenges in distinguishing the surface and subsurface effects. Metal crystals, isolated atoms, or metal nanoparticles in supported catalysts induce an electrophilic nature in subsurface, enhancing the catalysis efficiency. In this review, the influence of modification in subsurface of catalysts and their specific catalytic outputs are discussed. Key approaches and techniques for insertion of subsurface modifications and impact of electrophilicity upon catalysis upgradation are observed. A compilation of frequently used chemical reactions catalyzed by subsurface‐modified catalysts have been structured and thoroughly illustrated. [ABSTRACT FROM AUTHOR]

The study investigated the influence of catalyst concentration, co-catalyst loading ratio, sacrificial agent concentration, irradiation time, irradiation intensity and different pretreatments of sacrificial agent on hydrogen production, using multistage porous Pd/TiO 2 as the catalyst and kelp as the sacrificial agent. The morphological and structural changes in the catalyst, sacrificial agent, and their mixtures before and after the photocatalysis were analyzed using Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and ultraviolet–visible (UV–vis) spectroscopy. Based upon single-factor experiments, it was confirmed that mannitol was the primary substance acting as a sacrificial agent in kelp. Orthogonal experiments were conducted to determine the optimum conditions for hydrogen production with a reaction liquid volume of 100 mL. The highest hydrogen production efficiency was achieved for the following conditions: kelp sacrificial agent's concentration of 1.5 g/L; concentration of multistage porous Pd/TiO 2 catalyst of 3.5 g/L; Pd loading ratio of 1 wt%. Under these conditions, hydrogen production reached the value of 121.1 μmol in 4 h. Under the same conditions, replacing the kelp sacrificial agent with kelp treated with 4% alkali, resulted in a corresponding hydrogen production of 141.0 μmol in 4 h. Compared to other common biomass sacrificial agents, the use of kelp as a sacrificial agent for photocatalytic water splitting demonstrates superior hydrogen production performance. • Kelp is a suitable sacrificial agent for photocatalytic hydrogen production. • Synthesizes multistage porous Pd/TiO 2 for improved hydrogen production. • The primary substance acting as a sacrificial agent in kelp is mannitol. • Alkaline pretreatment optimizes kelp for photocatalytic hydrogen production. [ABSTRACT FROM AUTHOR]

With the increasing depletion of fossil fuels, hydrogen has attracted much attention as one of the promising alternative energy sources. However, the large-scale application of hydrogen energy still has many challenges, such as insufficient storage, transportation, and demand. Among the various hydrogen storage media, methylcyclohexane (MCH) is regarded as a potential hydrogen storage technology, because of its unique and excellent safety performance, hydrogen storage capacity, physical and chemical properties, and other notable characteristics. Herein, the paper focuses on the current research progress of dehydrogenation technology, which is discussed in term of the reaction mechanism of MCH dehydrogenation, the research progress of catalysts, and the optimization of process conditions, respectively. Subsequently, a summary is provided to point out the possible reaction network diagrams. Additionally, based on the challenges associated with sourcing heat for applications, we propose a novel dual internal combustion engine drive method for hydrogen production from MCH, this innovative approach is expected to propel the advancement and application of hydrogen energy technology. Then, this work concludes with a brief overview of the current research progress in hydrogenation technology. Finally, it summarizes the present challenges of MCH dehydrogenation, and further research of MCH dehydrogenation have prospected in terms of optimal design theory, preparation of novel catalysts, reduction of energy consumption, reactor enhancement, and system coupling. [Display omitted] • The reaction mechanism of MCH dehydrogenation is explored and analyzed. • A network diagram of possible MCH dehydrogenation reactions is summarized. • Progress in the research of active centers, additives, and supports of the catalysts is discussed. • A novel dual internal combustion engine drive method for hydrogen production from MCH is proposed. • The developments, challenges, and prospects for MCH dehydrogenation are reviewed. [ABSTRACT FROM AUTHOR]

A hybrid adhesive system composed of phenol-formaldehyde (PF) resin and polymeric methylene diphenyl diisocyanate (pMDI), modified with two types of alkaline catalysts, namely NaOH and CaCO3 at 20% (w/v), was used for manufacturing the oriented strand board (OSB) from sengon (Paraserianthes falcataria L. Nielsen) wood. The catalyst was added at a concentration of 1% of the solids content of PF adhesive, and pMDI was added at 2.5% and 5.0% of the PF adhesive solids content. Adding catalysts and cross-linking agents increased the solids content and viscosity of the adhesive and accelerated the gelation time. The water absorption of OSB increased with the addition of catalysts and crosslinking agents compared to the control PF. Still, the CaCO3 catalyst worked optimally in reducing the thickness swelling of OSB. The mechanical properties of the laboratory-fabricated OSB panels increased with the addition of catalyst and cross-linker, except for the modulus of elasticity parallel to the grain. The optimal performance of OSB was obtained by adding 1% CaCO3 and 2.5% pMDI based on the PF's solids content. [ABSTRACT FROM AUTHOR]

In this study, the photocatalytic degradation of an aqueous solution containing a mixture of Direct Black 10 B dye using titanium dioxide (TiO2) as a catalyst was investigated. The degradation of Direct Black 10 B dye was studied for several parameters, including the catalyst, dosage, initial concentration of dye, and pH. Variable catalyst quantities (0.25, 0.50, 0.75, 1, and 1.25 g), pH (3, 5, 9, and 11), and beginning dye concentration were used in the studies (62.5, 125, 250 and 500 ppm). 0.75 g/litre of catalyst was found to be the ideal dose. The ideal catalyst concentration was determined to be 0.75 g/litre, and the maximal dye decolourization rate was further studied in a basic media, i.e. at pH 9 Blue turned into grey and finally white in the acidic medium, whereas blue turned into pink and then white in the basic medium. After 3 hours 98% of the colour was completely removed at this optimal point. The Langmuir, Freundlich and Temkin isotherms were examined. The langmuier isothers with regression coefficient 0.99 is best fitted as compared to Freundlich and Temkin isotherms. The findings of the kinetic analysis suggest that the Pseudo Second order with regression coefficient 0.9923 is best suited as compared with the pseudo first order and Intra-particle diffusion model. [ABSTRACT FROM AUTHOR]

Compared to steam reforming, methanol aqueous-phase reforming (APR) converts methanol to hydrogen and carbon dioxide at lower temperatures, but also displays lower conversion rates. Herein, methanol APR is studied over the active Pt/Al2O3 catalyst under different operating conditions. Studies were conducted at different temperatures, pressures, methanol mass fractions, and residence times. APR performance was evaluated in terms of methanol conversion, hydrogen production rate, hydrogen selectivity, and by-product formation. The results revealed that an increase in operating pressure and methanol mass fraction had an adverse effect on the APR performance. Conversely, it was found that hydrogen selectivity was unaffected by the operating pressure and residence time for the methanol feed mass fraction of 5%. For the methanol feed mass fraction of 55%, hydrogen selectivity was improved by operating pressure and residence time. The alumina support phase change to boehmite as well as sintering and leaching of the catalytic particles were observed during catalyst stability experiments. Additionally, a comparison between methanol steam reforming (MSR) and APR was also performed. [ABSTRACT FROM AUTHOR]

Biodiesel, a potent replacement for petroleum diesel, is derived from fatty acids in biomass through transesterification, which is renewable, non-toxic, and biodegradable and is a powerful replacement for petroleum diesel. Lewis acid has been proven effective for esterification and transesterification. The Lewis base enhances the electrophilic and nucleophilic properties of the molecules that bind to it, leading to the remarkable versatility of the Lewis base catalytic reaction. Many studies have shown that Lewis acid/base catalyzed in situ transesterification is a fast and environmentally friendly method for producing biodiesel. The utilization of Lewis acid-base sites to catalyze transesterification has been shown to enhance their efficiency and utilization of acid-base active sites. This review explores biodiesel production by different catalysts using Lewis acid-base sites, the conditions for catalytic transesterification, the effects of different reaction parameters on biodiesel production, and the biodiesel production process. [ABSTRACT FROM AUTHOR]

Mesoporous HZSM-5 zeolites with nanocrystal stacking morphology were directly synthesized via hydrothermal methods without mesoporous templates. The synthesized mesoporous HZSM-5 was subjected to hydrothermal–citric acid washing treatment. The structural and acidic properties of the samples before and after modification were characterized using various techniques. The catalytic performance for butene conversion to propylene was investigated under atmospheric pressure, 500 °C, and a butene weight hourly space velocity (WHSV) of 10 h−1 in a continuous-flow micro-fixed bed reactor. The results show that propylene selectivity increased significantly from 24.7% before modification to 44%, and propylene yield increased from 22% to 38%. After 2 h of hydrothermal–citric acid washing modification, the catalyst maintained a butene conversion rate of 76% and a selectivity of 47% at 525 °C and a WHSV of 10 h−1 after 130 h of continuous reaction, with a propylene yield of 37%. The results indicate that moderate hydrothermal–citric acid washing modification leads to the removal of aluminum from the zeolite framework, reducing the amount and strength of acid but increasing the mesopore quantity. This helps control the reaction pathways and diffusion of intermediate products, suppresses some side reactions, and improves the selectivity and yield of the desired product, propylene, while significantly enhancing catalytic stability. [ABSTRACT FROM AUTHOR]

In this work, non-precious electrocatalysts were synthesized using the electrospinning technique. Ni12M8/CNF (M = Cd, Co, and Cu) catalysts were successfully prepared in a fixed ratio to withstand the optimum transition metal co-catalyst in addition to the role of CNFs as support in ion-charge movement through the catalyst surface. The prepared catalysts were physically studied by XRD, SEM, and TEM. The electrochemical activity was verified using different fuel concentrations, different sweeping scan rates, and electrochemical impedance. Ni12Cu8/CNFs showed the highest electrochemical activity reaching 152 mA/cm2 through different methanol concentrations. The outstanding performance is attributed to the large active surface area provided by carbon nanofibrous that eases the charge carrier transfer through the untrapped surface of the catalyst. The electrochemical tests suggest that Ni12Cu8/CNFs have the lowest ohmic impedance resistance ensuring the highest efficiency of the designed catalyst. The obtained results serve as an efficient catalyst for direct methanol electrooxidation reactions and suggest a possible application of a low-cost, easily accessible, and large surface area established via the preparing method. [ABSTRACT FROM AUTHOR]

Driven by the growing energy crisis and environmental concerns regarding the utilization of fossil fuels, biomass liquefaction has emerged as a highly promising technology for the production of renewable energy and value-added chemicals. However, due to the high oxygen content of biomass materials, biocrude oil produced from liquefaction processes often contains substantial oxygenated compounds, posing challenges for direct downstream applications. Catalytic hydrodeoxygenation (HDO) upgrading with hydrogen donors is crucial for improving the quality and applicability of biomass-derived fuels and chemicals. The costs, safety, and sustainability concerns associated with high-pressure gaseous hydrogen and organic molecule hydrogen donors are driving researchers to explore alternative and innovative biomass hydrodeoxygenation approaches without exogenous hydrogen donors. This review offers an overview of the recent developments in catalytic hydro-liquefaction and hydrodeoxygenation methods for biomass valorization without external hydrogen donation, including catalytic self-transfer hydrogenolysis using endogenous hydrogen in biomass structure, in situ catalytic hydrodeoxygenation employing water as the hydrogen donor, and in situ hydrodeoxygenation via water splitting assisted by zero-valent metals. The in situ hydrogen supply mechanisms and the impact of various hydrodeoxygenation catalysts on hydrogen donation efficiency using endogenous hydrogen are summarized in detail in this work. Furthermore, the current obstacles and future research demands are also discussed in order to provide valuable recommendations for the advancement of biomass utilization technologies. [ABSTRACT FROM AUTHOR]

Succinimide residues formed spontaneously from aspartic acid (Asp) and asparagine (Asn) residues in proteins and peptides are stereochemically unstable, undergoing partial l-to-d stereoinversion, and this is responsible for the d-Asp and d-β-Asp residues found in long-lived proteins. These stereoinverted abnormal amino acid residues are believed to be related to aging and some age-related diseases such as cataracts. Although the succinimide stereoinversion is nonenzymatic, a catalyst is required for it to occur at physiological temperature. In this study, it was found by density functional theory (DFT) calculations that a hydrogen phosphate ion (HPO42−) can effectively catalyze the stereoinversion of the succinimide intermediate. The HPO42− ion abstracts a proton from the asymmetric carbon atom of the succinimide residue to form an enolate intermediate. Then, while the resultant dihydrogen phosphate ion (H2PO4−) remains bound to the enolate ion, a water molecule donates a proton to the enolate intermediate on the opposite side from the phosphate (which is the rate-determining step) to produce the inverted carbon atom. The calculated activation barrier (ca. 90 kJ mol−1) is consistent with a slow in vivo reaction. The present found mechanism can be termed the "unsymmetrical SE1" or "pseudo-SE2" mechanism. [ABSTRACT FROM AUTHOR]

The novel heterogeneous catalyst, Bimetallic-organic framework (Fe, Cu)/carbon nanotubes encapsulated Ni nanoparticles, has been introduced for efficient degradation of acid orange 7 (AO7) via Fenton-like process. Optimizing and modeling of the heterogeneous degradation process were performed using response surface methodology (RSM) based on a five-level central composite design (CCD). The study on the individual and interaction effect of four operating parameters including pH, H2O2 concentration (mM), catalyst dose (mg L−1) and reaction time (min) revealed that the maximum AO7 degradation efficiency (93.94%) was achieved under optimal conditions of pH = 4.0, H2O2 concentration = 25 mM, catalyst dose = 200.0 mg L−1 and reaction time = 27 min (k = 0.1024 (min−1)). Analysis of scavenging revealed that tertiary butyl alcohol (TBA) led to a notable reduction in the degradation of AO7 under optimal conditions. The degradation of AO7 dropped from 93.94% to 14.28% as TBA concentrations varied from 0 to 9 mmol L−1. Consequently, the rate constant of the degradation reaction decreased from 0.1002 to 0.0058 min−1 as the concentration of the quenching agent increased. Interestingly, it was found that besides the role of Fe, Cu and Ni species in the Fe0.6Cu0.3Ni0.1(BDC)@CNT, surface oxygen-functional groups on the CNT provides faster and efficient Fe(III)/Fe(II) cycle over a broader pH range. Furthermore, concerning the importance of economic and environmental issues, the possibility of regenerating the Fe0.6Cu0.3Ni0.1(BDC)@CNT catalyst for four consecutive cycles has been confirmed. The concluding observations of this study provide favorable outcomes in the development and utilizing the advanced MOF-based catalysts with the aim of effective environmental remediation. [ABSTRACT FROM AUTHOR]

In the present report, we have described the synthesis of N-aminopolyhydroquinoline (N-PHQ) derivatives using highly efficient β-cyclodextrin (β-CD) as a catalyst by the Hantzsch condensation of substituted aromatic aldehydes, dimedone, and hydrazine hydrate in one pot. The reactions were completed in a shorter time without the generation of any other byproduct. The synthesized N-PHQs were washed thoroughly with distilled water and recrystallized with ethanol to get highly purified products (as crystals). The structure of the synthesized N-PHQs was established by using advanced spectroscopic techniques like FT-IR, NMR (1H, 13C, DEPT, COSY, and HSQC), ESI-MS, and Elemental Analyzer. The N-PHQs derivatives demonstrated moderate to excellent resistance against the tested strains (both fungal as well as bacterial). The presence of polar groups, which are able to form H-bonds, attached to the phenyl ring like -NO2 (4b and 4c), and -OMe (4i, 4j, and 4k) exhibits excellent activity, which is comparable to standard drugs, amoxicillin and fluconazole. [ABSTRACT FROM AUTHOR]

This overview provides insights into organic and metal–organic polymer (OMOP) catalysts aimed at processes carried out in the liquid phase. Various types of polymers are discussed, including vinyl (various functional poly(styrene-co-divinylbenzene) and perfluorinated functionalized hydrocarbons, e.g., Nafion), condensation (polyesters, -amides, -anilines, -imides), and additional (polyurethanes, and polyureas, polybenzimidazoles, polyporphyrins), prepared from organometal monomers. Covalent organic frameworks (COFs), metal–organic frameworks (MOFs), and their composites represent a significant class of OMOP catalysts. Following this, the preparation, characterization, and application of dispersed metal catalysts are discussed. Key catalytic processes such as alkylation—used in large-scale applications like the production of alkyl-tert-butyl ether and bisphenol A—as well as reduction, oxidation, and other reactions, are highlighted. The versatile properties of COFs and MOFs, including well-defined nanometer-scale pores, large surface areas, and excellent chemisorption capabilities, make them highly promising for chemical, electrochemical, and photocatalytic applications. Particular emphasis is placed on their potential for CO2 treatment. However, a notable drawback of COF- and MOF-based catalysts is their relatively low stability in both alkaline and acidic environments, as well as their high cost. A special part is devoted to deactivation and the disposal of the used/deactivated catalysts, emphasizing the importance of separating heavy metals from catalysts. The conclusion provides guidance on selecting and developing OMOP-based catalysts. [ABSTRACT FROM AUTHOR]

This study investigates methods to enhance the efficiency of CO2 capture using organic amine absorption and compares the performance of traditional and novel amine solvents. It reviews various single-component and mixed amine absorbents, as well as catalysts used in these methods, highlighting the superiority of mixed amine absorbents over single-component amine absorbents in CO2 absorption and desorption. Additionally, the study explores the catalytic mechanisms and effects of catalysts in the CO2 absorption/desorption process with amine solvents and provides an outlook on future research directions. The aim is to promote the widespread adoption of organic amine absorption technology in industrial applications and to contribute to the development of more sustainable and efficient CO2 capture technologies. [ABSTRACT FROM AUTHOR]

This study is focused on the modelling of the production of bio-oil by thermochemical liquefaction. Species Acacia melanoxylon was used as the source of biomass, the standard chemical 2-Ethylhexanol (2-EHEX) was used as solvent, p-Toluenesulfonic acid (pTSA) was used as the catalyst, and acetone was used for the washing process. This procedure consisted of a moderate acid-catalysed liquefaction process and was applied at 3 different temperatures to determine the proper model: 100, 135, and 170 °C, and at 30-, 115-, and 200-min periods with 0.5%, 5.25%, and 10% (m/m) catalyst concentrations of overall mass. Optimized results showed a bio-oil yield of 83.29% and an HHV of 34.31 MJ/kg. A central composite face-centred (CCF) design was applied to the liquefaction reaction optimization. Reaction time, reaction temperature, as well as catalyst concentration, were chosen as independent variables. The resulting model exhibited very good results, with a highly adjusted R-squared (1.000). The liquefied products and biochar samples were characterized by Fourier-transformed infrared (FTIR) and thermogravimetric analysis (TGA); scanning electron microscopy (SEM) was also performed. The results show that invasive species such as acacia may have very good potential to generate biofuels and utilize lignocellulosic biomass in different ways. Additionally, using acacia as feedstock for bio-oil liquefaction will allow the valorisation of woody biomass and prevent forest fires as well. Besides, this process may provide a chance to control the invasive species in the forests, reduce the effect of forest fires, and produce bio-oil as a renewable energy. [ABSTRACT FROM AUTHOR]

The global increase in energy consumption, driven by population growth and improved living standards, has led to a heavy reliance on fossil fuels, causing significant environmental concerns. This has prompted a shift toward sustainable energy sources, with biomass, especially lignocellulosic forest biomass, emerging as a key alternative due to its abundance and carbon-neutral potential. Microwave-assisted pyrolysis (MAP) is an efficient method for converting forest biomass into valuable bioproducts and bioenergy with reduced energy use. This review introduces biomass types, focusing on forest biomass and its role in global energy production. It compares MAP to conventional pyrolysis, highlighting the benefits of rapid, uniform heating and improved product yields. Key operational conditions, such as temperature, microwave power, biomass size, and catalyst ratios, are discussed in relation to their impact on product quality and yield. Despite its advantages, MAP faces challenges, particularly in temperature control, which can affect bio-oil yield and quality. High temperatures may cause unwanted secondary reactions, while low temperatures can lead to incomplete decomposition. Research into biomass dielectric properties and process modeling is essential in order to optimize MAP and scale it up for industrial use. Addressing bio-oil quality issues through catalytic upgrading is also critical for broader adoption. [ABSTRACT FROM AUTHOR]

Polyurethane (PU) belongs to a unique class of polymers. Different properties of PU such as mechanical strength and biocompatibility can be enhanced by co-polymerizing it with different bio and synthetic polymers. It finds huge applications as micro-reactors for the fabrication of metal nanoparticles (MNPs) owing to the synergistic properties of both polyurethane and fabricated metal nanoparticles. Metal nanoparticles fabricated polyurethane have gained much attention in the last few years. These types of nanocomposites hyphenate the mechanical properties of polyurethane with the high surface-to-volume ratio of metal nanoparticles. Here, this review article briefly evaluates different methods of synthesis of polyurethane-based metal nanocomposites and their characterization via different techniques to evaluate their properties. Applications of these polyurethane based nanocomposite materials have also been described critically in different fields depending upon their catalytic, antimicrobial and antifungal potential. Future directions of these nanocomposite materials have also been described in the field of designing of nano-filters and nano-devices in order to attain environmental remediation and sustainability. [ABSTRACT FROM AUTHOR]

ABSTRACT Schiff bases are introduced as versatile pharmacophores for the design and development of various bioactive compounds. Oxime‐based Schiff base ligands form an important and flexible class of ligands that have attracted attention due to their wide applications in various fields. Here, novel 3‐(2‐hydroxyphenyl‐imino)butan‐2‐one oxime, (HPIO) Schiff base and Zn(II) complexes derived from it, [Zn(bpy)(HPIO)](NO3)2, C1, (bpy = 2,2′‐bipyridine) and [Zn(HPIO)2]Cl2, C2, were synthesized and characterized. Theoretical studies showed that both complexes are reactive and have high pharmacological affinity. Experimental investigations were done to compare some biological properties of the complexes. Antioxidant studies using ·DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) assay presented the following trend: C1 > C2 > HPIO. Considering the importance of the antioxidant enzyme catalase in removing reactive oxygen species (ROS), the binding process of C1/C2 with catalase was evaluated. Kinetic studies showed that C1/C2 can inhibit the catalytic performance of catalase by mixed‐type inhibition mechanism. The C1 and C2 quenched the catalase fluorescence emission with static quenching mechanism. The binding affinity to catalase was higher for C1 than C2 (Kb = 1.51 and 0.89 × 105 M−1 for C1 and C2, respectively at 305 K). In C1/C2 interaction with catalase, which was an exothermic and spontaneous process, hydrogen bonds, van der Waals forces, and hydrophobic interactions played a decisive role and strongly confirmed by molecular docking data. Tracking the structural changes of catalase showed that enzyme undergoes structural changes in the presence of both complexes. [ABSTRACT FROM AUTHOR]

Green heterogeneous bifunctional catalyst is sustainable for the production of biodiesel owning to its reusability, eco-friendly, and bifunctionality. In this work, a green heterogeneous bifunctional Zeolite-A/Biochar (Z-A/BC) catalyst was synthesized for the production of biodiesel from waste cooking oil (WCO) through one-pot esterification-transesterification reaction. The functional group, elemental composition, crystallographic structure, and morphology of the synthesized catalyst were characterized using FT-IR, EDX, XRD, and SEM, respectively. Furthermore, the catalytic proficiency of the synthesized catalyst was tested by optimizing methanol to oil ratio, catalyst amount, temperature, and reaction time. The maximum biodiesel yield (86.22%) was achieved at 2.5% wt. of catalyst amount, 10:1 of methanol to oil molar ratio, 70 °C of reaction temperature, and 240 min of reaction time. The synthesized Z-A/BC catalyst showed apparent catalytic efficiency than its parent materials Z-A (69.42%) and BC (74.27%). The recyclability of Z-A/BC catalyst was also found to be 86.22, 82.98, 79.08, 62.87, and 76.84% for 1st, 2nd, 3rd, 4th, and 5th cycles, sequentially which is cost effective. Furthermore, the physicochemical properties such as density, ash content, FFA, acid value, saponification value, and kinematic viscosity of the produced biodiesel were analyzed by comparing with standards. These results showed good agreement with ASTM and EN14214 biodiesel standards. Therefore, the produced biodiesel using heterogeneous bifunctional Z-A/BC catalyst from WCO could be used as an alternative engine fuel with/without blending with commercial diesel. [ABSTRACT FROM AUTHOR]

Solid ammonia dosing technology has been extensively researched in the last decade as an effective solution to address issues such as urea crystallization and carrier blockage in traditional selective catalyst reduction (SCR) systems. In this study, a comparison of nitrogen oxide (NOx) conversion efficiency between solid ammonia dosing (SAD) and Adblue dosing on a heavy-duty diesel engine SCR system was conducted. First, an engine emission test bench with SAD SCR and Adblue SCR systems was established. Subsequently, both dosing systems were tested and studied on the engine emission test rig. The results showed that the NOx conversion efficiency of SAD was slightly improved by approximately 2%–5% when the catalyst upstream temperature exceeded 250°C, compared with the Adblue system. This improvement can be attributed to the better mixing ability of SAD. Additionally, SAD demonstrated significant advantages in avoiding issues related to urea decomposition at low exhaust temperatures. Furthermore, similar results were observed in the emission cycle test results of the engine. Under the European steady-state cycle (ESC) and European transient cycle (ETC) conditions, the NOx conversion efficiency of SAD was only slightly higher than that of the Adblue system by about 2%. However, under the world harmonized transient cycle (WHTC) condition, where more low-temperature operating conditions are included, the beneficial weighted NOx conversion efficiency of SAD increased to approximately 7.4% at a release condition of 190°C. [ABSTRACT FROM AUTHOR]

A new type of Ni/Al2O3 self‐supporting catalysts, with high specific surface area, was fabricated by blow‐spinning technology. These Ni/Al2O3 self‐supporting catalysts are hollow flexible fibers and were utilized for the dry reforming of methane. The Ni/Al2O3 catalysts exhibited exceptional catalytic performance, maintaining their activity for over 150‐h at a high temperature of 800°C. The Ni nanoparticles disputed on the hollow fibers demonstrated remarkable resistance to sintering and coking during high‐temperature catalysis. This was a noteworthy feature, as sintering and coking are common challenges faced by catalysts during high‐temperature reactions. Furthermore, the catalysts retained its activity even after a rigorous 150‐h test at 800°C, indicating its durability and stability. Importantly, the Ni/Al2O3 self‐supporting could be successfully reactivated after the test, further highlighting its reusable nature. This study offers promising new avenues for the development of high‐temperature, self‐supporting, and reactivatable catalysts. [ABSTRACT FROM AUTHOR]

A novel electrochemical reactor with a rotating anode attached to its end with four baskets as catalysts holders is proposed for deep desulfurization of diesel fuel. In this reactor two experimentally prepared catalysts of (5% manganese oxide (MnO2)/modified activated carbon (MAC) and 5% iron oxide (Fe2O3)/MAC) were used for an efficient desulfurization process. This design is characterized by conducting two functions at the same time, which are to agitate the reaction mixture and to move the catalyst over all areas of the reaction vessel. Several experiments were conducted at different operating conditions such as voltage, reaction time, and agitating speed. Results showed that the proposed basket reactor is excellent and highly effective in removing dibenzothiophene (DBT) in diesel. The removal efficiency of sulfur compounds is significantly improved by enhancing reaction times, stirring speed, and cell voltage up to 3 volts and drops at higher than 3 volts. At all operating conditions, the 5% Fe2O3/MAC catalyst showed higher performance than the 5% MnO2/MAC catalyst. This result can be attributed to the high reactivity of Fe2O3/MAC toward DBT removal and its magnetic activity which could enhance the oxidation reaction. Under the best operating conditions, the removal efficiencies reached 98.8%, and 93.1% for 5% Fe2O3/MAC and 5% MnO2/MAC, respectively. A model for the proposed reactor was also developed using an artificial neural network (ANN) software. The modeling data displayed an excellent agreement between the experimental and predicted data. This interactive model produced an accurately strong basis for the behavior of the new electrochemical desulfurization (ECDS) process. [ABSTRACT FROM AUTHOR]

Herein is studied the soot oxidation over platinum group metal oxide/CeO2–ZrO2 (PGM/CZ) catalysts. The ability to capture gas-phase oxygen was in sequence of Ru/CZ > Rh/CZ > Ir/CZ > Pt/CZ > Pd/CZ. A soot oxidation test by TG-DTA showed that Ru/CZ, Rh/CZ, and Ir/CZ are highly active catalysts. It was found that there is a good correlation between the ability to capture gas-phase oxygen and soot oxidation activity. TEM observation revealed that soot oxidation mainly occurs at the interface between soot and CZ surfaces. The Ea values and soot oxidation test using labelled oxygen suggest that highly active catalysts oxidize soot by CZ lattice oxygen. For Ir/CZ, soot oxidation at 270 °C occurred due to the reduction by soot. Ru/CZ and Rh/CZ captured gas-phase oxygen spontaneously below 250 °C, resulting in soot oxidation at 270 °C. H2-TPR results suggest that the reactivity of lattice oxygen in the CZ surface, improved by PGM, is also related to soot oxidation activity. This suggests that the ability to capture gas-phase oxygen and the reactivity of lattice oxygen in the CZ surface determine the soot oxidation activity, and that Ru, Rh, and Ir have the effect of enhancing these properties. [ABSTRACT FROM AUTHOR]