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In the title compound, C9H11N3O·CH4O, the semicarbazone moiety is nearly planar [maximum deviation = 0.017 (2) Å] and is twisted by a dihedral angle of 29.40 (13)° with respect to the phenyl ring. The semicarbazone moiety and phenyl ring are located on opposite sides of the C=N bond, showing the E configuration. An intermolecular O—H...O and N—H...O hydrogen-bonding network occurs in the crystal structure.

Various excellent catalysts have been explored for the methanolysis of polycarbonate (PC), but it is still challenging to develop green and economical catalysts for solvent-free PC methanolysis to recover both bisphenol A (BPA) and dimethyl carbonate (DMC). Herein, green, efficient and solvent-free degradation of PC to BPA and DMC was achieved using urea as a cheap green catalyst. At 140 °C for 3 h, PC was completely degraded to BPA and DMC with yields of 93.4% and 74.7%, respectively. A possible catalytic degradation mechanism of PC was proposed by kinetic experiments and NMR, where urea, methanol and carbonate formed a six-membered ring in the reaction. It was found that the increase of urea concentration significantly reduced the activation energy, which was attributed to the fact that the increase of urea concentration made the six-membered ring easier to form and activated the carbonate bond. The degradation system can be reused directly up to 10 times and 100% degradation rate can be maintained. This work provides a simple, green and economical method for industrial PC recycling. [ABSTRACT FROM AUTHOR]

The present review proposes an approach for remediation of atmosphere pollution by carbon dioxide. The global economic growth nowadays requires extensive energy consumption. Energy is produced traditionally by combustion of carbon containing fuels, resulting in the release of large amounts of carbon dioxide in the atmosphere. These emissions of released CO2 lead to the greenhouse effect on the atmosphere with subsequent impact on the global climate. Remediation of this harmful effect requires reduction in CO2 emissions. In addition to improving the efficiency of energy consumption, this reduction can be also accomplished by the recycling of carbon dioxide into fuels and useful commodities. This conversion of CO2 into fuels and commercial products leads to multiple benefits such as reduction in carbon emissions and greenhouse gases, production of value-added goods, thus reducing oil consumption and associated pollutions of the environment. This review summarizes the efforts to remove, or at least to remediate, the release of carbon dioxide in the atmosphere by its conversion to value-added products prior to discharging. Some of these products are urea, methanol, formic acid, some polymers of practical importance, light hydrocarbons and methane. The recent achievements in chemical catalysis, electrochemistry, bioelectrochemistry and photocatalysis are considered. Discussion on the feasibility of the considered methods compared to the traditional technologies is made. It is concluded that although production of value-added chemicals by carbon dioxide recycling is not yet competitive, it seems promising in the future when its economic feasibility will become a reality. [ABSTRACT FROM AUTHOR]

Polycrystalline carbon nitride thin films were deposited on Si(400) and ITO coated glass substrates by electrolysis of methanol–urea solution under high voltage, at atmospheric pressure and at temperatures below 350 K. Fourier transform infrared spectroscopy (FTIR) measurements of the films deposited on Si suggested the existence of single, double and triple carbon–nitrogen bonds in the films. A maximum N/C atomic ratio of 0·81 was achieved in the films as measured by C/H/N analysis. X-ray diffraction spectra of the films grown with different urea concentrations showed various peaks for different d values, which could be assigned to different crystalline carbon nitride phases. Selected area electron diffraction patterns measured by transmission electron microscopy (TEM) showed a number of concentric sharp rings, corresponding to various planes of theoretically predicted β-C3N4 phase. Scanning electron microscopy (SEM) images of the films indicated the existence of grains, the number density and size of which were dependent on the solute concentration. Optical transmission measurements of the films on ITO coated glass substrates revealed a band gap value of around 2·87 eV for direct transition. The hardness of the films on Si substrates was as high as 28 GPa. [ABSTRACT FROM AUTHOR]

High-entropy multi-elemental (HEM) electrocatalysts present superior catalytic performance due to the efficient synergism of their components. HEM electrocatalysts are usually prepared through hydrothermal reactions or calcination, which could generate undesired heterogeneous structures that hinder the exploration of the structure-property relationship of these HEM electrocatalysts. Herein, we report a sol-gel method to synthesize homogeneous HEM electrocatalysts for electro-oxidation of methanol and urea (methanol oxidation reaction (MOR) and urea oxidation reaction (UOR)), through an acid-catalyzed gelation at room temperature. With Ni as the primary component for MOR and UOR, Co can reduce the overpotentials, while Fe can increase the catalytic activities and durability. Borate and phosphate can tune the charge distribution in active sites and speed up the reaction kinetics through fast proton transfer. Thus, the optimal Ni2Fe0.5Co0.5-BP HEM catalyst demonstrates superior catalytic activity together with good durability and great resistance to CO poisoning. In addition, a direct methanol fuel cell with Ni2Fe0.5Co0.5-BP electrode can not only provide power, but also produce formic acid with high yield and high Faraday efficiency. This work presents a simple strategy to prepare high-performance HEM electrocatalysts for fuel cells and production of value-added chemicals. [ABSTRACT FROM AUTHOR]

Various technologies including carbon capture and utilization or sequestration (CCUS) have been defined to achieve sustainability. CCUS aims to reduce global anthropogenic CO2 emissions to tackle climate change by capturing carbon at the source of emission and prevent its entry into the atmosphere. The captured carbon is then either utilized in industries or sequestered geologically. CO2 capture is accomplished by employing several methods like the use of membranes, chemical looping, cryogenic distillation, etc. Membranes provide a more effective and economic alternative as compared to the options that exist currently. Hence, in this paper we try to scrutinise the properties of certain mixed matrix membranes (MMM), alumina and zeolite-based membranes among others with respect to their selectivity towards flue gases, hoping to provide a broader understanding of current technology. The potential use of ionic liquids (ILs) to enhance properties of membranes will also be discussed. Next, this paper investigates the existing as well as possible carbon utilization pathways. Existing pathways include the usage of CO2 in the manufacturing of fertilizers, urea, methanol, oil and gas recovery in addition to water desalination projects and electrochemical conversion to certain chemicals. While we observe that ILs and MMMs provide good alternatives, an extensive further research is, however, still required for implementation of these ideas on an industrial scale. [ABSTRACT FROM AUTHOR]

Near-infrared light-triggered photocatalytic water treatment has attracted significant attention in recent years. In this novel research, rational sonochemical fabrication of Ag2S/g-C3N4 nanocomposites with various compositions of Ag2S (0–25) wt% was carried out to eliminate hazardous rhodamine B dye in a cationic organic pollutant model. g-C3N4 sheets were synthesized via controlled thermal annealing of microcrystalline urea. However, black Ag2S nanoparticles were synthesized through a precipitation-assisted sonochemical route. The chemical interactions between various compositions of Ag2S and g-C3N4 were carried out in an ultrasonic bath with a power of 300 W. XRD, PL, DRS, SEM, HRTEM, mapping, BET, and SAED analysis were used to estimate the crystalline, optical, nanostructure, and textural properties of the solid specimens. The coexistence of the diffraction peaks of g-C3N4 and Ag2S implied the successful production of Ag2S/g-C3N4 heterojunctions. The band gap energy of g-C3N4 was exceptionally reduced from 2.81 to 1.5 eV with the introduction of 25 wt% of Ag2S nanoparticles, implying the strong absorbability of the nanocomposites to natural solar radiation. The PL signal intensity of Ag2S/g-C3N4 was reduced by 40% compared with pristine g-C3N4, implying that Ag2S enhanced the electron–hole transportation and separation. The rate of the photocatalytic degradation of rhodamine B molecules was gradually increased with the introduction of Ag2S on the g-C3N4 surface and reached a maximum for nanocomposites containing 25 wt% Ag2S. The radical trapping experiments demonstrated the principal importance of reactive oxygen species and hot holes in destroying rhodamine B under natural solar radiation. The charge transportation between Ag2S and g-C3N4 semiconductors proceeded through the type I straddling scheme. The enriched photocatalytic activity of Ag2S/g-C3N4 nanocomposites resulted from an exceptional reduction in band gap energy and controlling the electron–hole separation rate with the introduction of Ag2S as an efficient photothermal photocatalyst. The novel as-synthesized nanocomposites are considered a promising photocatalyst for destroying various types of organic pollutants under low-cost sunlight radiation. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cell (MSC) therapy aids cardiac repair and regeneration, but the low rate of MSC survival and engulfment in the infarcted heart remains a major obstacle for routine clinical application. Here, an injectable suspension of human acellular amniotic membrane (HAAM) that may serve as synergistic cell delivery vehicle for the treatment of myocardial infarction (MI) by improving MSC homing and survival is developed. The results demonstrate that compared with MSC transplantation alone, HAAM‐loaded MSCs have higher survival and engraftment rates in infarcted tissue, alleviated hypoxia‐induced myocardial damage, achieved higher improvements in cardiac function, promoted angiogenesis, and reduced myocardial fibrosis. In addition, HAAM‐loaded MSCs increase N‐cadherin levels and thereby enhance the efficacy of MSCs in treating MI. This study provides a new approach for MSC‐based cardiac repair and regeneration. [ABSTRACT FROM AUTHOR]

The demand for food-grade β-mannanases, ideal for high-temperature baking, is increasing. Using the Komagataella phaffii (P. pastoris) expression system for β-mannanase production, this study aimed to enhance purification methods. We evaluated better conditions for production and purification of β-mannanase (PpRmMan134A) from recombinant P. pastoris X-33, focusing on a higher purity and reducing the production of endogenous secretory proteins in fermentation. By adjusting carbon and nitrogen sources, culture time, and temperature, we controlled cell growth to reduce the production of endogenous secretory proteins. The better-evaluated conditions involved culturing recombinant P. pastoris in 70 mL buffered glycerol complex medium for 24 h at 30 °C, then in modified buffered methanol-complex medium with 0.91% (w/v) methanol, 0.56% (w/v) sorbitol, and 0.48% (w/v) mannitol for another 24 h, which improved the PpRmMan134A yield and reduced endogenous secretory proteins, shortening the fermentation time by 72 h. An affordable purification method using ultrafiltration and salt-out precipitation was utilized. PpRmMan134A showed thermostability up to 100 °C and effectively degraded locust bean gum into smaller fragments, mainly producing mannotriose. In conclusion, with its enhanced purity due to reduced levels of endogenous secretory proteins, purified PpRmMan134A emerges as a promising enzyme for high-temperature baking applications. [ABSTRACT FROM AUTHOR]

Seven fatty acids were detected by GC-MS in Xanthoceras sorbifolium Bunge seed oil extracted at different temperatures, including Palmitic acid C16:0, Stearic acid C18:0, Oleic acid C18:1, Eicosenoic acid C20:1, Docosenoic acid C22:1, Tetracosenoic acid C24:1, and Linoleic acid C18:2. The highest content of nervonic acid (NA) was found in Xanthoceras sorbifolium Bunge seed oil extracted at 70 °C. Three methods were selected to analyze the extraction rate of nervonic acid in Xanthoceras sorbifolium Bunge seed oil, including urea complexation, low-temperature solvent crystallization, and a combined treatment using these two methods. The final content of nervonic acid obtained was 14.07%, 19.66%, and 40.17%, respectively. The combined treatment method increased the purity of nervonic acid in Xanthoceras sorbifolium Bunge seed oil by 12.62 times. Meanwhile, thermogravimetric behavior analysis of samples extracted using different methods was conducted by thermogravimetric analyzer, which suggested that the thermal stability of the samples extracted by the combined treatment was enhanced. These results can provide a new process parameter and scientific basis for the extraction of NA. At the same time, FTIR and NMR were also used to characterize the combined extraction sample, and the structure of the samples was proved. [ABSTRACT FROM AUTHOR]

Hyperpolarization has become a powerful tool to enhance the sensitivity of magnetic resonance. A universal tool to hyperpolarize small molecules in solution, however, has not yet emerged. Transferring hyperpolarized, labile protons between molecules is a promising approach towards this end. Therefore, hydrogenative parahydrogen-induced polarization (PHIP) was recently proposed as a source to polarize exchanging protons (PHIP-X). Here, we identified four key components that govern PHIP-X: adding the spin order, polarizing the labile proton, proton exchange, and polarization of the target nucleus. We investigated the last two steps experimentally and using simulations. We found optimal exchange rates and field cycling methods to polarize the target molecules. We also investigated the influence of spin relaxation of exchanging protons on the target polarization. It was found experimentally that transferring the polarization from protons directly bound to the target X-nucleus (here 13C) of lactate and methanol using a pulse sequence was more efficient than applying a corresponding sequence to the labile proton. Furthermore, varying the concentrations of the transfer and target molecules yielded a distinct maximum 13C polarization. We believe this work will further help to understand and optimize PHIP-X towards a broadly applicable hyperpolarization method. Hyperpolarization has become a powerful tool to enhance the sensitivity of NMR analyses, whereby hydrogenative parahydrogen-induced polarization with exchanging protons could broaden its applicability. Here, the authors identify four key components that govern the polarization of exchanging protons, and propose optimal exchange rates and field cycling methods to polarize target molecules. [ABSTRACT FROM AUTHOR]

Hierarchical porous structures and well-modulated interfacial interactions are essential for the performance of electrode materials. The energy storage performance can be promoted by regulating the diffusion behavior of the electrolyte and constructing a coupled interaction at heterogeneous interfaces. Herein, we have synthesized ultrathin NiO nanosheets anchored to nitrogen-doped hierarchical porous carbon (NiO/N-HPC) and applied it to construct aqueous potassium ion hybrid capacitors (APIHCs). The abundant and interconnected porous architecture promotes electrolyte penetration/diffusion and shortens the ion transport path, thereby accelerating storage reaction kinetics. The nitrogen-doped carbon support can achieve optimized metal oxides–carbon interaction and enhance the adsorption ability for the electrolyte ions, leading to earning higher storage capacity. Consequently, the prepared NiO/N-HPC exhibits a superior capacitance of 126.4 F g−1 at a current density of 0.5 A g−1, and the as-fabricated NiO/N-HPC//N-HPC APIHC achieves an ultra-high capacitance retention of 91.6% over 8000 cycles at a current density of 2 A g−1. Meanwhile, the APIHC device shows an excellent energy density of 21.95 W h kg−1 and a power density of 9000 W kg−1. [ABSTRACT FROM AUTHOR]

Cancer is most frequently treated with antineoplastic agents (ANAs) that are hazardous to patients undergoing chemotherapy and the healthcare workers who handle ANAs in the course of their duties. All aspects related to hazardous oncological drugs illustrate that the monitoring of ANAs is essential to minimize the risks associated with these drugs. Among all analytical techniques used to test ANAs, electrochemistry holds an important position. This review, for the first time, comprehensively describes the progress done in electrochemistry of ANAs by means of a variety of bare or modified (bio)sensors over the last four decades (in the period of 1982–2021). Attention is paid not only to the development of electrochemical sensing protocols of ANAs in various biological, environmental, and pharmaceutical matrices but also to achievements of electrochemical techniques in the examination of the interactions of ANAs with deoxyribonucleic acid (DNA), carcinogenic cells, biomimetic membranes, peptides, and enzymes. Other aspects, including the enantiopurity studies, differentiation between single-stranded and double-stranded DNA without using any label or tag, studies on ANAs degradation, and their pharmacokinetics, by means of electrochemical techniques are also commented. Finally, concluding remarks that underline the existence of a significant niche for the basic electrochemical research that should be filled in the future are presented. [ABSTRACT FROM AUTHOR]

In New Zealand, agriculture accounts for around 50% of total gross greenhouse gas emissions, energy production and use account for 40%. Given the limited possibility of reducing methane from the agricultural sector, we focus on the shape of, and factors influencing, the energy-related emissions profile. A single framework that combines environmental input–output analysis with structural decomposition analysis is established to systematically investigate driving forces shaping energy-related greenhouse gas emissions at national and sectoral levels. Results show that emission intensity, population, and consumption volume are dominant factors influencing shifting the energy-related emissions profile from 2007 to 2013. To achieve a net-zero-carbon economy, decarbonizing the transport sector is foremost and should be given priority. Policy directed at improving energy utilization in private consumption and exports, and the adoption and utilization of advanced technology in manufacturing, would contribute to achieving emissions reduction targets. [ABSTRACT FROM AUTHOR]

The perspectives of technological advances needed for short term energetic transition are briefly reviewed and discussed critically. In particular, the technologies for the greenhouse gas emission-free production of electrical energy, its storage and transport, the production, transport, storage and use of hydrogen, and the use of biomass derived technologies are shortly and critically reviewed. Critical aspects are emphasized. The role of chemistry, and in particular materials chemistry and engineering, in short-term developments are underlined. [ABSTRACT FROM AUTHOR]

The ability of various cosolutes and cosolvents to enhance or quench solvent density fluctuations at solute–water interfaces has crucial implications on the conformational equilibrium of macromolecules such as polymers and proteins. Herein, we use an extended hydrophobic solute as a model system to study the effect of urea and methanol on the density fluctuations in the solute's solvation shell and the resulting thermodynamics. On strengthening the solute–water/cosolute repulsive interaction, we observe distinct trends in the mutual affinities between various species in, and the thermodynamic properties of, the solvation shell. These trends strongly follow the respective trends in the preferential adsorption of urea and methanol: solute–water/cosolute repulsion strengthens, urea accumulation decreases, and methanol accumulation increases. Preferential accumulation of urea is found to quench the density fluctuations around the extended solute, leading to a decrease in the compressibility of the solvation shell. In contrast, methanol accumulation enhances the density fluctuations, leading to an increase in the compressibility. The mode of action of urea and methanol seems to be strongly coupled to their hydration behavior. The observations from this simple model is discussed in relation to urea driven swelling and methanol induced collapse of some well-known thermo-responsive polymers. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) utilization technologies have emerged as a promising approach to address the direct and indirect consequences of climate change and the need for sustainable resource management. Those innovative technologies aim to capture and utilize CO2 by converting it into valuable products or directly using it as a chemical feedstock in various industries, thus, avoiding their release into the atmosphere. In this study, different CO2 utilization pathways including CO2 to chemicals and fuels, CO2 to building materials, CO2 to enhanced oil recovery (EOR), and CO2 to bio‐products are discussed in terms of their status – economic, environmental and technology readiness level performances. Moreover, various CO2 utilization pathways are comparatively analyzed considering their advantages and drawbacks, CO2 uptake potentials, and overall climate benefits. According to the comparison results, photocatalytic and electrochemical reduction of CO2 along with the bio‐fixation of CO2 are gaining more attention in the recent research and investigations, from the energy intensity and environmental point of view, whereas EOR remains dominant in terms of the scalability, maturity and economic benefits. However, limitations of EOR related to the capacity, life cycle and different geolocations, as well as the complexities of other mature approaches make room for emerging technologies to be more energy‐effective and environmentally friendly. Overall, most of the promising CO2 utilization techniques are either technologically immature or limited in scale to deploy globally. One of the main barriers to reusing CO2 is associated with the high cost of CO2‐based production and the low value of the CO2 market. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

The achievement of global climate targets outlined in the Paris Agreement represents a critical challenge in the coming decades. Certain industry sectors cannot completely avoid all emissions from their processes. In this context, the term unavoidable or Hard-to-abate emissions is used. Carbon Capture and Utilization (CCU) and Carbon Capture and Storage (CCS) are recognized as essential components for addressing those emissions to achieve Net Zero Emissions. To identify effective Carbon Management Strategies, balancing future CO2 sources and possible sinks for achieving long-term climate targets is essential. Especially in Austria hardly any comprehensive studies have been carried out. This work presents a comprehensive analysis of Austria's CO2 point sources as well as their projected development until 2050 based on technology-based scenarios. Geological CO2 storage in Austria is primarily feasible in former hydrocarbon reservoirs and saline aquifers. Future demands for CO2 as CCU feedstock will arise in the chemical industry. By 2050, industry will emit approximately 4 Million tons (Mt) of unavoidable CO2 annually. These emissions must be stored in the long term and correspond to the minimum demand for CCS. Fugitive emissions from agriculture, for example, cannot be captured. Thus, they are not subject of CCU/S measures. Negative emissions are therefore necessary to achieve the climate targets. These negative emissions and the possible use of CO2 as feedstock are covered by biogenic CO2. [ABSTRACT FROM AUTHOR]

• Waste-to chemicals and Power-to-X technologies are discussed. • Focus on syngas production/use and related catalysis aspects. • These are crucial technologies to use alternative C-sources in short-/medium-term. • Techno-economic feasibility of waste-to-chemical approach is shown. • Application-side constrains in CO 2 methanation catalysts have to be considered. After briefly introducing the future scenario for energy and chemical production to remark the need to develop new catalytic routes to use C-sources alternative to fossil resources, this perspective paper discusses two key technologies in this direction to move beyond fossil fuels: i) waste-to-chemical, with a discussion of the techno-economic aspects to convert municipal solid wastes to base chemicals (urea, methanol, olefins), and ii) power-to-X, with focus on CO 2 methanation. Attention is on the role of syngas in the future scenario, evidencing some of the open questions for catalysis on these technologies. For CO 2 methanation, it is highlighted that the crucial aspects of catalysts development are often not properly addressed, in spite of the abundant literature. [ABSTRACT FROM AUTHOR]

• Study evaluates generation from biomass gasification. • Syngas is used within poly-generation systems to generate sustainable fuels. • The article considers recycling of multiple sources of biomass to generate syngas. • A new poly-generation process to produce urea, liquids fuels and power is proposed. • A novel hybrid environmental and economic optimisation methodology is proposed. The production of renewable chemicals and fuels is driving modern society towards a type of sustainable development which involves a decreasing dependency on fossil fuels and the minimisation of waste. Biomass, a waste by-product from the urban environment, is a carbon dioxide neutral organic fuel that can potentially serve as a feedstock for the production of sustainable power and heat. Gasification is preferred over the other thermal conversion options for biomass processing whereby the product synthesis gas can be utilised to power generators/turbines and generate clean energy, ammonia and methanol. Incidentally, efficient and economically sound biomass driven supply chains can be integrated into an existing petrochemical infrastructure. Moreover, the potential production volumes of fuels and green chemicals can also be increased by the addition of multiple biomass sources, thereby creating potential positive scale effects. This study proposes a new poly-generation process that utilises multiple sources of biomass feedstock to produce high quality urea, methanol, Fisher-Tropsch liquids and power. Four flowsheet configurations are simulated using Aspen Plus software and the built-in capabilities of the activated analysis using Aspen Process Economic Analyzer and Aspen Energy Analyzer to perform the economic, energy and environmental impact calculations. The results demonstrate that the methanol production technique is the most economic process pathway with a net profit of approximately $0.035 per kg of biomass input, whilst the urea process pathway presents the lowest environmental impact solution with approximately 0.71 kg of CO 2 -e per kg of biomass input. These results are relative and can be analysed from different perspectives based on the market demand of the products and their applications and local need. For instance, considering at the economic and environmental indicators relative to the production capacity, production of liquid fuels achieve net profits of approximately $0.27 per kg of product, whilst urea production demonstrates the lowest environmental emissions of approximately 3.93 kg of CO 2 -e per kg of product. [ABSTRACT FROM AUTHOR]

Rh has been widely studied as a catalyst for the promising hydrazine oxidation reaction that can replace oxygen evolution reactions for boosting hydrogen production from hydrazine‐containing wastewater. Despite Rh being expensive, only a few studies have examined its electrocatalytic mass activity. Herein, surface‐limited cation exchange and electrochemical activation processes are designed to remarkably enhance the mass activity of Rh. Rh atoms were readily replaced at the Ni sites on the surface of NiOOH electrodes by cation exchange, and the resulting RhOOH compounds were activated by the electrochemical reduction process. The cation exchange‐derived Rh catalysts exhibited particle sizes not exceeding 2 nm without agglomeration, indicating a decrease in the number of inactive inner Rh atoms. Consequently, an improved mass activity of 30 A mgRh−1 was achieved at 0.4 V versus reversible hydrogen electrode. Furthermore, the two‐electrode system employing the same CE‐derived Rh electrodes achieved overall hydrazine splitting over 36 h at a stable low voltage. The proposed surface‐limited CE process is an effective method for reducing inactive atoms of expensive noble metal catalysts. [ABSTRACT FROM AUTHOR]

An innovative simple, sensitive, and selective method has been developed and validated for quantification of hazardous Allura red (AR, E129) dye in beverages. Allura red (AR) is a synthetic dye that is commonly used in the food industry to give foods a bright and appealing color. The method is based on microwave-assistant nitrogen-doped carbon quantum dots (N@CQDs) from a very cheap source with a high quantum yield equal to (36.60%). The mechanism of the reaction is based on an ion-pair association complex between AR and nitrogen-doped carbon quantum dots (N@CQDs) at pH 3.2. The reaction between AR and N@CQDs led to a quenching effect of the fluorescence intensity of N@CQDs at 445 nm after excitation at 350 nm. Moreover, the quantum method's linearity covered the range between 0.07 and 10.0 µg mL− 1 with a regression coefficient is 0.9992. The presented work has been validated by ICH criteria. High-resolution transmission electron microscopy (HR-TEM), X-ray photon spectroscopy (XPS), Zeta potential measurements, fluorescence, UV-VIS, and FTIR spectroscopy have all been used to fully characterize of the N@CQDs. The N@CQDs were successfully utilized in different applications (beverages) with high accuracy. [ABSTRACT FROM AUTHOR]

The world is moving towards decarbonization policies in the energy and industrial sectors to bring down carbon dioxide release and reach net zero emissions. Technologies to capture CO2 and use it as a feedstock to produce CO2-based chemicals and biofuels via chemical or biochemical conversion pathways can potentially reduce the amount of CO2 released. The paper serves the innovative scientific knowledge for CO2 transformation via a biochemical pathway to microalgal biomass with its subsequent treatment to biofuels and bioproducts assuming milder climatic conditions (Central or Eastern Europe, Visegrad countries or climatically related world regions). The recent trends were critically reviewed for microalgal biorefinery to reach the sustainability of microalgal-based chemicals with added value, digestion, hydrothermal liquefaction, pyrolysis, and gasification of microalgal residues. Knowledge-based chemical process engineering analysis, systematic data synthesis, and critical technical evaluation of available life cycle assessment studies evaluated the sustainability of microalgal biorefinery pathways. The research showed that biological CO2 fixation using water, seawater or wastewater to produce third-generation biomass is a promising alternative for bioethanol production via pretreatment, enzymatic hydrolysis, digestion, and distillation, and can be realized on a large scale in an economically viable and environmentally sound manner. Its best economically promising and sustainable pathway is perceived in producing microalgal-based nutraceuticals, bioactive medical products, and food products such as proteins, pigments, and vitamins. Machine learning methods for data mining, process control, process optimization, and geometrical configuration of reactors and bioreactors are the crucial research needs and challenges to implementing microalgal biorefinery in an operational environment. [ABSTRACT FROM AUTHOR]

Aqueous photoelectrochemical (PEC) cells have long been considered a promising technology to convert solar energy into hydrogen. However, the solar‐to‐H2 (STH) efficiency and cost‐effectiveness of PEC water splitting are significantly limited by sluggish oxygen evolution reaction (OER) kinetics and the low economic value of the produced O2, hindering the practical commercialization of PEC cells. Recently, organic upgrading PEC reactions, especially for alternative OERs, have received tremendous attention, which improves not only the STH efficiency but also the economic effectiveness of the overall reaction. In this review, PEC reaction fundamentals and reactant‐product cost analysis of organic upgrading reactions are briefly reviewed, recent advances made in organic upgrading reactions, which are categorized by their reactant substrates, such as methanol, ethanol, glycol, glycerol, and complex hydrocarbons, are then summarized and discussed. Finally, the current status, further outlooks, and challenges toward industrial applications are discussed. [ABSTRACT FROM AUTHOR]

Results of the study of CO2 methanation on Co-containing catalysts based on Siral aluminosilicates with different SiO2/Al2O3 ratios (1, 10, and 40) are presented. It is shown that methane is the main product at temperatures up to 573 K, its yield varies depending on the SiO2/Al2O3 ratio of aluminosilicate. Carbon monoxide is formed along with methane at temperatures above 573 K. Maximum methane yields of 55% and 41% (at 573 K) are achieved on Co/Siral-1 and Co/Siral-10 catalysts. It is shown that catalysts reduced in a hydrogen flow are characterized by the presence of superpara/ferromagnetic particles and magnetic resonance parameters of their EMR spectra significantly depends on the SiO2/Al2O3 ratio of the aluminosilicate. It is assumed that the superpara/ferromagnetic particles formed during high-temperature hydrogen treatment of Co-containing aluminosilicates are catalytically active particles in the methanation of carbon dioxide. [ABSTRACT FROM AUTHOR]

Abstract In this research we report a complex material formed between poly (methyl methacrylate) (PMMA) and urea. The disassociation temperatures of the PMMA/U complexes are higher than the glass transition temperature of neat PMMA and lower than the melting temperature of neat urea. As we reported previously, the as received-PMMA (asr-PMMA) contained a small amount of residual alkane-like surfactant. When forming the PMMA/U complexes with saturated urea-methanol solution, the originally contained contaminant can be encapsulated by urea in the form of a crystalline inclusion compound (IC) and dispersed within the PMMA/U complex. Since urea has been reported to form ICs with various small molecules, this phenomenon provides a potential way for small molecule encapsulation by using PMMA as the substrate and urea as the encapsulant. Graphical abstract Image 1 Highlights • A self-assembled complex material formed by PMMA and urea. • PMMA/U complexes are mixed with the coincidently formed small molecule-U-IC. • A novel way for small molecule immobilization in a PMMA substrate. [ABSTRACT FROM AUTHOR]

The article focuses on essentials of steam turbine design and analysis. The steam turbines are important components of process plant utility systems. They gives opportunities for optimizing steam supply reliability, as well as sitewide energy efficiency. Steam turbines are common in the oil refining, ammonia and urea, methanol, ethylene, and pulp and paper industries.

Permeability coefficients ( P's) and apparent activation energies ( Es) for nonelectrolyte permeation across the toad urinary bladder have been analyzed in terms of the thermodynamics of partition between membrane lipids and water. Particular attention has been paid to the contributions made by −CH− and −OH groups: on the average, the addition of one −CH− group to a molecule increases P fourfold, while the addition of one −OH group reduces P 500-fold. Using these changes in P, we have calculated the incremental free energies (δΔ F), enthalpies (δΔ H), and entropies (δΔ S) for partition, hydration, and solution in membrane lipids. The results for toad bladder have been compared and contrasted with those extracted from the literature for red blood cells, lecithin liposomes, and bulk phase lipid solvents. The partition of −CH− groups into toad bladder and red cell membranes is dominated by entropy effects, i.e., a decrease in entropy of the aqueous phase that 'pushes' the group out of water, and an increase in entropy of the membrane lipid that 'pulls' the group into the membrane. This process resembles that in 'frozen' liposome membranes. In 'melted' liposomes and bulk lipid solvents the free energy of solution in the lipid is controlled by enthalpy of solution. Partition of −OH groups in all systems is governed by hydrogen bonding between the −OH group and water. However, the solution of the −OH group in toad bladder membranes is complex, and processes such as dimer and tetramer formation in the lipid phase may be involved. The results presented in this and the previous paper are discussed in terms of the structure of phospholipid bilayer membranes. Attention is drawn to the possible role of structural defects in the quasi-crystalline structure of the lipid (so-called 2 gl kinks) in the permeation of small molecules such as water, urea, methanol and acetamide. [ABSTRACT FROM AUTHOR]

The calcium-dependent regulatory proteins, calmodulins, have been isolated from human blood platelets and guinea pig peritoneal polymorphonuclear leucocytes using the urea methanol procedure of Grand et al. [Biochem. J. 177,521-529 (1978)]. The calmodulins were purified to homogeneity as indicated by polyacrylamide gel electrophoresis and both proteins comigrated with bovine brain calmodulin with mobilities corresponding to molecular weights of 16000-17000. The yield of calmodulin from platelets was higher on a wet weight basis than the yield from leucocytes but the former compared favourably with yields reported for brain and other tissues. Both calmodulin preparations significantly stimulated brain cyclic nucleotide phosphodiesterase, erythrocyte ghost Ca2+ ATFase and platelet phosphorylase kinase activities at the microgram level. Stimulation of Lubrol-solubilised brain adenylate cyclase was only marginally significant with platelet calmodulin and rarely demonstrable with the leucocyte preparations. Although biological activities of both proteins were retained during storage at 20 °.C higher-molecular-weight aggregates slowly formed which could not be dissociated during dodecylsulphate/rnercaptoethanol denaturation. [ABSTRACT FROM AUTHOR]

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Since the discovery of urea inclusion compounds (UICs) in 1940, the handedness of this chiral helical system has not been established experimentally. Here three UIC systems containing only light atoms were studied. The optical rotations were first measured, and the absolute structures of the enantiomorphic domains of three UICs were determined by single crystal X‐ray diffraction (SCXRD). The correlation between the optical rotation and the absolute configuration of the UICs was finally established, showcasing the power of absolute structure determination by SCXRD, which is essential in structural chemistry and pharmaceutical research. [ABSTRACT FROM AUTHOR]

Direct Ethanol Fuel Cells (DEFCs) are important clean energy conversion systems which can reach high energy densities using inexpensive and non-toxic fuels. One of the main obstacles to using DEFC systems is the high cost of platinum or platinum-alloy electrodes traditionally used in these systems. However, other less expensive co-catalysts, e.g., transition metal complexes, can be used to partially replace platinum or platinum-alloys in Pt-based electro-catalysts. The aim of this study is to describe and analyze the use of a new uranyl salen-type complex as co-catalyst in ethanol electro-oxidation. To this end, the structural and spectroscopic properties of the co-catalyst in question was investigated by single-crystal X-ray diffraction, DFT, elemental analysis (CHN), FTIR, UV-Vis, and 1H and 13C NMR. Cyclic voltammetry indicated a quasi-reversible redox pair at 0.97/0.69 V (E1/2 = 0.83 V) along with an anodic process at 1.14 V, both associated to the phenolate/phenoxyl radical couple. Six PtSn-based catalysts were produced by varying the PtSn:uranyl complex molar ratio. The ethanol oxidation reaction was investigated in acidic media via cyclic voltammetry and chronoamperometry. Direct scanning of the samples indicated that the peak-current density for the 6 : 1 PtSn/C : [UO2(3-OMe-c-salcn)H2O] catalyst was higher than that for other catalyst ratios. Moreover, as compared to the pure PtSn catalyst, 6 : 1 PtSn/C : [UO2(3-OMe-c-salcn)H2O] exhibited better catalytic activity in ethanol electro-oxidation reaction (EOR); it decreased the onset potential during ethanol oxidation. In addition, this catalyst exhibited peak-current densities about 2.3 times that of PtSn/C. pH affected the catalytic system performance, which decreased as pH increased (maximum efficiency at pH 0.3). Ethanol oxidation catalyzed by 6 : 1 PtSn/C : [UO2(3-OMe-c-salcn)H2O] was also investigated using cyclic voltammetry and chronoamperometry at different ethanol concentrations, indicating that the EOR peak increased as ethanol concentration increased. [ABSTRACT FROM AUTHOR]

The electrospinning method has been successfully employed to prepare various percentages of less expensive nickel/palladium (NP) nanofiber catalysts as an alternative to platinum in direct methanol fuel cells (DMFC). The chemical structure, morphological characteristics, and electrochemical (EC) properties have been investigated using a variety of analysis techniques. According to the scanning electron microscope (SEM), all prepared samples with different Pd concentrations exhibit good nanofiber form and a distinct nanoparticle look. Transmission electron microscopy (TEM) reveals an amorphous carbon nanofiber structure with imbedded crystalline spheres of nickel and palladium. The carbonized polyvinyl alcohol nanofibers (PVANFs) have a steady and even distribution of nickel and palladium with an accurate nickel and palladium content, according to the energy dispersive X‐ray mapping results. The lack of hydroxide or oxide phases in the X‐ray diffraction (XRD) pattern proves that Ni–Pd nanoparticles are present in the metallic phase. For the electrooxidation of methanol, urea, and an isopropanol‐methanol mixture, the electrocatalytic features of the fabricated samples have been examined. EC results show that methanol has the best electrocatalytic properties. Hence, NP nanofiber catalysts could be a promising candidate to replace platinum in DMFC. [ABSTRACT FROM AUTHOR]

Coal, a solid fossil fuel, consists of organic and inorganic matter. Its complex structure contains fused aromatic moieties, constituting a three‐dimensional macromolecular coal structure network. More efficient utilisation technologies are required to ensure coal becomes a considerably cleaner source of energy in the future. Due to the increase in energy, liquid fuels, and combustible gas demands, coal utilisation is necessary for some developing countries such as Pakistan, Turkey, and India. Furthermore, coal is globally being used to produce liquid fuels and combustible gases. The benefits and drawbacks of various Fischer‐Tropsch synthesis catalysts are discussed. For clean coal carbonisation, blends of coal and biomass, which are the current trends in decarbonising the coal industries, should be adopted and the chemistry of coal carbonisation should be investigated further, especially the phenomenon that occurs at the plastic layer (300–550 °C). In addition, the clean co‐gasification technology presented in this work could be adopted and successfully implemented through government and industry initiatives to study and test coal/biomass for co‐gasification and advanced modelling and simulation of the co‐gasification plant. [ABSTRACT FROM AUTHOR]

The development of non-precious, efficient, and nanostructured electrocatalysts using a facile method to replace noble metal-based electrocatalysts has received wide attention in the field of fuel cell technology. In this study, a highly efficient and non-precious electrocatalyst was fabricated via facile and in situ two-step method. The electrocatalyst that has been developed relies on the utilization of nickel-copper alloy nanoparticles (NiCu), which have been supported on porous carbon nanosheets (PCNs). The preparation method involved a microwave-assisted fabrication of carbon quantum dots with nickel and copper ions chelated on their surface, followed by calcination to produce NiCu@PCNs. The structure and the surface morphology of NiCu@PCNs were investigated by TGA, XRD, TEM, and SEM techniques. XRD results proved that the average size of bimetallic Ni-Cu is 18.31 nm, and PCNs are made up of 9.33 stacked graphitic layers. TEM image confirmed that NiCu NPs are encapsulated into carbon and distributed over the PCNs, forming a core-shell nanostructure. The electrocatalysts, NiCu@PCNs, possess a favorable electrochemically active surface area of 116 cm−2 and exhibit superior electrocatalytic performance for methanol oxidation in comparison to urea. The onset potentials value of methanol and urea oxidation were 0.34 V and 0.38 V vs. Ag/AgCl and the highest current densities of 140 and 62 mA cm−2, respectively. This study provides a simplistic method for the design of PCNs-supported bimetallic nanoparticles, which can serve as non-precious electrocatalysts and an alternative to noble metal-based catalysts. [ABSTRACT FROM AUTHOR]

Abstract Electrochemical oxidation of small molecules (e.g., water, urea, methanol, hydrazine, and glycerol) has gained growing scientific interest in the fields of electrochemical energy conversion/storage and environmental remediation. Designing cost‐effective catalysts for the electrooxidation of small molecules (ESM) is thus crucial for improving reaction efficiency. Recently, earth‐abundant amorphous transition metal (TM)‐based nanomaterials have aroused souring interest owing to their earth‐abundance, flexible structures, and excellent electrochemical activities. Hundreds of amorphous TM‐based nanomaterials have been designed and used as promising ESM catalysts. Herein, recent advances in the design of amorphous TM‐based ESM catalysts are comprehensively reviewed. The features (e.g., large specific surface area, flexible electronic structure, and facile structure reconstruction) of amorphous TM‐based ESM catalysts are first analyzed. Afterward, the design of various TM‐based catalysts with advanced strategies (e.g., nanostructure design, component regulation, heteroatom doping, and heterostructure construction) is fully scrutinized, and the catalysts’ structure‐performance correlation is emphasized. Future perspectives in the development of cost‐effective amorphous TM‐based catalysts are then outlined. This review is expected to provide practical strategies for the design of next‐generation amorphous electrocatalysts.

The GE Chilled Ammonia Process (CAP) is a post combustion CO 2 capture technology that produces a high purity CO 2 product stream that can be utilized in the existing and new markets. The development of the CAP technology began with laboratory bench-scale experiments to confirm that aqueous ammonia solution effectively absorbs CO 2 with sufficiently low vapor phase ammonia emissions at reduced temperatures. From these results, a technology development program was initiated to scale-up and validate the process for commercialization. The approach taken here is illustrative of industrial scale process development and improvement. For the CAP CO 2 capture technology, the development effort involved an iterative approach as information from the different development stages was obtained to set environmental & economic targets, develop predictive tools and models for process optimization, and to support validation efforts at operating facilities. Over the course of the program, the technology was successfully tested on flue gasses produced from coal, oil, and natural gas combustion, in addition to flue gas produced from refinery applications. Process know-how and operational experience was gained and together with validated data from bench-scale and pilot plant facilities was returned to push process design improvement and the development of predictive models. Currently, the CAP design is also modified and extended into applications involving Urea, Methanol, and Soda Ash Production. While many lessons learned and process improvement opportunities have been extracted from pilot plant and other test facilities, pilot plant results and process modeling studies are still unveiling potential for further improvement. Optimization and integration with the power generation facility occurred in the development phases of several FEED studies for large CCS plants. The CAP design is ready for a demonstration-scale project and now is much improved from the design that was tested originally at laboratory bench-scale. For example, the CAP scrubbing solution is now operated in a non-solids mode where precipitation is not a part of the overall operational strategy and the process flow scheme is now modified and improved from original flow schemes implemented at early pilot facilities to improve performance at reduced cost. This work summarizes the bench-scale, pilot-scale, and validation facility results and offers insights into the lessons learned and effort required bringing the technology into commercialization at an industrial scale. The lessons learned from each of the pilot plants at different sizes are illustrated and the associated impact of the results from each pilot plant in the current CAP product offering is also discussed. A summary of the important results from CAP test facilities including Stanford Research International (SRI), WE energies, EONCAP-Karlshamm, AEP Mountaineer, TCM and GE's pilot facility in Vaxjo, Sweden are presented. Distinguishing features of the GE CAP are provided drawing comparison to open literature versions of ammonia based CO 2 capture processes. Evolution of key performance parameters such as energy demand, product quality, solvent strength, process flow scheme, etc., at the different plant sizes are also discussed. In addition, the current state of development for extending the technology into areas where CO 2 may be utilized productively are also be addressed in addition to the latest improvement concepts currently being studied on CAP. Finally, the paper will also summarize the advantages of CAP as compared to conventional amine based processes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Establishing a life cycle sustainability evaluation system from technical, economic, and environmental perspectives. • Proposing a novel integrated MCDM model to aggregate multi-dimensional sustainability performances. • Coping with the external and internal uncertainties in judgments and decision-making. • Providing a well-informed benchmark to support the screening and selection of CO 2 conversion technologies. • Exploring the improvement opportunities and limits for short- and mid-term implementation in industries. With the emergence of numerous CO 2 chemical conversion technologies to simultaneously reduce CO 2 emissions and produce value-added products, it is of great importance to compare their difference and select the most sustainable routes for future development. This study quantitatively evaluated the sustainability performances of 21 alternative CO 2 conversion technologies from economic, technical, and environmental perspectives and developed a novel Multi-criteria Decision-making (MCDM) model to prioritize the alternatives. To cope with the external and internal uncertainties during the decision-making, Interval-Rough Numbers (IRNs) were firstly used to deal with subjective vagueness and information incompleteness involved in the group judgements unavoidably. Secondly, DEMATEL-ANP was employed based on IRNs to specify the correlation type and degree among diverse criteria for determining the global weights accurately. Lastly, a Vector-based Algorithm method was applied to measure the alternatives' overall performance and figure out the final ranking scores of sustainability. The results revealed that CO 2 to methane, urea, methanol, dimethyl ether, and acetic acid were the top five promising conversion technologies with the highest R&D priority over the next decades from a sustainability perspective. Moreover, a detailed sensitivity analysis of criteria weights was conducted to scrutinize the effectiveness of the ranking results and to validate the reliability of the new proposed MCDM model. Furthermore, in consideration of the complexity of future technological advance, market transformation, economic and social trends, this life cycle sustainability decision-support framework for CO 2 conversion technologies provides a well-informed benchmark to support the screening and selection of candidate technologies including both the existing and emerging processes, and strategically explore the development opportunities and limits under uncertainties. [ABSTRACT FROM AUTHOR]