查看更多>>摘要：Exploring high-efficient and stable low-cost electrocatalysts is of significant importance for boosting the efficiency of water splitting and purifying urea-enriched wastewater. Herein, bimetallic doping strategy was adopted to obtain jasminum nudiflorum-like Fe, V doped NiS arrays (Fe, V-NiS/NF) via typical hydrothermal process and subsequent anion exchange reaction. The as-obtained Fe, V-NiS/NF array displays high catalytic activity and stability toward oxygen evolution reaction (OER) and urea oxidation reaction (UOR) in alkaline media, with reduced overpotentials of 273 and 214 mV to deliver the current density of 50 raA cm~(-2) for OER and UOR, respectively. More notably, when employing Fe, V-NiS/NF as symmetric electrolytic cell for urea electrolysis, a low cell voltage of 1.45 V is needed at 10 mA cm~(-2), which is about 110 mV lower than the conventional water electrolysis. Meanwhile, the catalyst also displays superior stability for over 72 h. Such outstanding performance is attributed to the following points: (i) 3D porous flower-like structure facilitates the mass transfer and abundant exposure of active sites; (ii) in situ growth of catalysts on conductive substrate and the effective interface engineering of different composition shorten the charge transport pathways and expedite electron transfer. Density functional theory calculations demonstrate that the Fe and V dopants regulate the electronic environment of Ni sites and optimize the adsorption free energy of urea. This work provides a universal pathway to design high-efficient and non-noble electrocatalysts for H2 production in an energy-saving way via urea electrolysis.
查看更多>>摘要：The safety of using nano-emulsion drug delivery systems is a growing concern. Here, we conducted risk assessments of an innovative combination therapy for multidrug resistant pathogens by encapsulating cephalosporin antibiotics and (3-lactamase inhibitors with chitosan nanoparticles (CNAIs) using in vitro human cell lines and an in vivo animal model, Caenorhabditis elegans. The four combinations of CNAIs including two cephalosporin antibiotics (cefotaxime and ceftiofur) with two p-lactamase inhibitors (ta-zobactam and clavulanate) were engineered as water-oil-water emulsions. CNAIs maintained stable antimicrobial activity in various thermal challenges. CNAIs exerted strong antimicrobial activity but did not cause toxicity in human cell lines measured by cell membrane integrity, mitochondria activity, and reactive oxygen species generation. Reported damage was observed at 8 μg/mL and 16 ug/mL for only two of the four combinations of CNAIs. More importantly, CNAIs at 4 μg/mL did not cause adverse effects on the lifespan of C. elegans. In summary, CNAIs do not cause toxicity at working concentration in vitro and in vivo risk assessments, suggesting that nano-emulsion drug delivery systems can be a new framework for developing treatments for multidrug pathogen infections.
查看更多>>摘要：Methanol to Gasoline (MTG) process transforms methanol to hydrocarbons within the boiling point range of gasoline. The result is a wide spectrum of products (olefins, paraffins, aromatics and naphthenics, among others), with the total conversion of methanol to hydrocarbons and water. Catalyst deactivation by coke is a main problem in this process. This work aims to determine the feasibility of carrying out the production of gasoline from methanol in a two-zone fluidized bed reactor (TZFBR). The hypothesis is that the formation of carbonaceous deposits (coke) on the catalyst particles can be counteracted by its combustion in the regeneration zone that this novel reactor presents, thus achieving stable and continuous operation. In this way, both processes (reaction and regeneration) would be being carried out simultaneously in the same reactor (process intensification). The comparison of results between a conventional fluidized bed reactor and a TZFBR shows that the second one actually provides a better stability over time.
查看更多>>摘要：Peptides are an important recognition element for small molecules and have been used in the field of biological analysis. However, it has been rarely reported that a novel method combining peptides as recognition elements with covalent organic framework (COF) as catalytic amplification signal to construct highly sensitive and selective three-mode molecular spectroscopy. In this paper, high catalytic and stable three COFs were prepared, and the catalysis of the new indicator nanoreaction of HAuCl4-sodiumformate (Fo) was studied by molecular spectral slope procedure. The produced gold nanoparticles (AuNPs) exhibit a strong resonance Rayleigh scattering (RRS) peak at 370 nm and surface plasmon resonance absorption (Abs) peak at 540 nm. In the presence of molecular probes, a strongest surface-enhanced Raman scattering (SERS) peak was generated at 1617 cm~(-1). Combining the COF_(TpBD) amplification indicator reaction with specific peptide (FT) reaction of Cu~(2+), a novel, sensitive and selective SERS/RRS/Abs assay platform was established, with a SERS linear range of 0.005-0.115 nmol/L Cu~(2+). In addition, the two working curves of lg[Cu~(2+)] vs SERS and [Cu~(2+)] vs SERS intensity, and the nanocatalytic mechanism were discussed.
查看更多>>摘要：In this study, waste crab shell was hydrothermally carbonized and then activated to prepare an effective and recyclable adsorbent. The adsorption performance of the adsorbent for different dyes was investigated through adsorption experiments, and the results showed that it had the largest adsorption performance for malachite green. Furthermore, the adsorption performance and mechanism of malachite green were investigated by static and dynamic adsorption method. The crab shell biochar could remove 6142.5 mg g~(-1) of malachite green within 3 minutes, indicating that the crab shell biochar could ultra-rapid and highly efficient adsorb malachite green. In addition, the malachite green adsorbed on the crab shell biochar could be removed by calcination, which achieved the entire regeneration of the crab shell biochar. The adsorption of malachite green by crab shell biochar adsorbent conformed to the pseudo-second-order kinetic model, the Dubinin-Radushkevich and Langmuir isotherm adsorption model. Physical and chemical characterization indicated that the adsorption mechanism of malachite green included alkaline fading effect, hydrogen bonding and n-n interaction.
查看更多>>摘要：Performing carbon dioxide (CO2) capture in an environmentally benign and cost-effective way is challenging owing to several factors including selectivity. Thus, the development of polymers that provide high capacity and selectivity for the removal of CO2 gas is important. N-based porous polymers are promising for CO2 capture due to their abundant porosity, variable surface characteristics, and great stability. Herein, porous organic polymers were synthesized by microwave-assisted Freidel-Crafts alkylation of 2,2'-bipyridine and pyrrole with dimethoxymethane as a cross-linker. The synthesized polymers were characterized by Fourier transform infrared, nuclear magnetic resonance, thermogravimetric analyzers, and surface analyzers based on Brunauer-Emmett-Teller theory (BET). The porous polymers exhibited high surface areas of 580-930 m~2/g. The polymers showed high ideal adsorbed solution theory (IAST) selectivity of 53-63 toward CO2 over N2 at 1 bar and 298 K under flue gas composition. Whereas the selectivity toward CO2 over CH4 at 1 bar and 298 K under natural gas composition was 12-18. The synthesized polymers achieved exceptional H20 adsorption capacity at P/P0 = 0.9 and 293 K of 35-45 mmol/ g. The results reveal the polymers provide promising candidates for the CO2 capture from various mixtures, such as flue gas and natural gas.
查看更多>>摘要：Epoxy monoacrylate resins are widely used in a myriad of industrial applications; however, their shelf life still requires improvement. This work investigates the use of acryl phosphate [mixture of 2-(methacryloyloxy)ethyl phosphate and bis(2-(methacryloyloxy)ethyl) phosphate] as a reactive additive to increase the long-term storage stability of epoxy monoacrylate resins. A series of epoxy monoacrylate resins were synthesized via addition esterification reaction of diglycidylether bisphenol-A (DGEBA) with acrylic acid at different mole ratios. The epoxy equivalent weight, viscosity, and acrylation portion of the synthesized epoxy monoacrylate resin increased with increasing the acrylic acid content, and the optimization of the mole ratio of DGEBA and acrylic acid allowed obtaining a high-purity epoxy monoacrylate resin. The investigation of the storage stability of the epoxy monoacrylate resin formulated with acryl phosphate revealed that no viscosity was developed after 12 weeks, which demonstrates that the additive increased the long-term shelf life of the resin.
查看更多>>摘要：In this study, a new decision-supporting platform for the overall supply chain management of the petrochemical industries was proposed to maximize business profits. The proposed system integrates various decision-supporting models that address the critical challenges, both vertically and horizontally. Specifically, horizontal integration includes various decision-based problems along with the productive flow on the value chain from raw material purchasing and manufacturing to the final product sales, while vertical integration involves critical decisions at different levels, including the enterprise supply chain, the plant scheduling/planning, and the process operation. The optimization-based decision platform effectively supports the business's supply chain management, plant planning, and process operation strategy. The platform integrates different decision and featuring models, including a price prediction and a paper trading model for reducing the financial risks, a mathematical model of naphtha thermal cracker for identifying the optimal operating, and an optimization model for maximizing business profits. As a result, business profit was improved by 5.30% with only paper trade optimization, 6.67% with optimal operating conditions combined with price forecasting, and 11.98% with overall supply chain optimization. Thereby, the proposed platform assists decision-makers in determining the timing and quantity of raw material purchases and final product sales, as well as the operation strategies for process facilities, utilities, and inventory management. This study could be used to aid in the establishment of annual planning and scheduling as an auxiliary indicator for business operations.
查看更多>>摘要：A non-thermal plasma with a wet scrubber (NTP + WS) was used to degrade gaseous toluene. Compared with the NTP + WS/H2O system, the toluene and by-product ozone removal efficiencies were increased by 10% and 85% in the NTP + WS/Fe~(2+) system, respectively. For 60 ppm toluene degradation, the maximum mineralization rate (MR) of toluene (61%) was obtained, at the optimum Fe~(2+) concentration of 50 mg/L. During catalytic oxidation, the removal efficiency of toluene was limited by its solubility in WS systems. In addition, decreased Fe~(2+) concentration and accumulation of organics led to the system deactivation. The EPR and quenching experiments verified the presence and contribution of hydroxyl radicals (4.6%) and superoxide radicals (3.8%) to the removal efficiency of toluene. Based on the radicals and intermediates detected in the gas and liquid phases, a degradation mechanism for toluene in the NTP + WS/Fe~(2+) system was proposed.
查看更多>>摘要：The degradation of TBP has become a stumbling block to the industrial continuous production of lithium chloride extraction from brines with high Mg/Li ratio by solvent extraction. To develop a more stable and more efficient extraction system, a novel amide system, containing newly synthesized extractant N,N-bis (2-ethylhexyl)-2-methoxyacetamide (NBEHMOA), FeCl3 6H20 and sulfonated kerosene, was proposed in this work. Compared with TBP and N523, NBEHMOA extracted Li+ and H+ in the sequence of TBP > NBEHMOA > N523 and N523 > TBP > NBEHMOA respectively. The solution containing 5.5 mol/L LiCl and 0.5 mol/L HC1 was used as the eluent in the scrubbing process. A Li+ extraction efficiency of 96.7% and 22.31 g/L Li+ in the stripping solution were achieved by the whole process with counter-current twelve stages. The extraction mechanism investigated via FT-IR spectroscopy illustrated that the metal ions Fe~(3+) and Li+ were mainly coordinated by the carbonyl C = 0 in NBEHMOA. This novel amide system can successfully achieve the cascade extraction effect for lithium, Li/Mg separation and avoid the generation of phase interface objects through counter-current extraction of lithium from brine at a lower acidity. This work provided a novel extraction system to recover lithium from the higher magnesium/lithium ratio brines.
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