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Supercritical CO[sub.2] (scCO[sub.2]) is a versatile solvent for polymer processing; however, many partially fluorinated polymers exhibit limited solubility in neat scCO[sub.2]. Organic cosolvents such as toluene can enhance polymer–solvent interactions, thereby improving solubility. The cloud point behavior of poly(2,2,2-trifluoroethyl methacrylate) (poly(TFEMA)) at 3 wt% concentration in scCO[sub.2]–toluene binary mixtures was investigated over a temperature range of 31.5–50 °C and toluene contents of 0–20 wt%. Solvent mixture densities were estimated using the Altuin–Gadetskii–Haar–Gallagher–Kell (AG–HGK) equation of state for CO[sub.2] and the Tait equation for toluene. For all compositions, the cloud point pressure was observed to increase linearly with temperature. The cloud point pressure decreased monotonically with increasing toluene concentration and at the highest concentration of 20 wt% was reduced by approximately 40% in comparison to neat scCO[sub.2]. The addition of toluene lowered the solvent density, but the increase in solvent–solute molecular interactions resulted in the observed decrease in cloud point pressure. Toluene is shown to be an effective cosolvent for dissolving poly(TFEMA) in scCO[sub.2], offering a promising approach to lowering operating pressures in fluoropolymer processing. Our results provide valuable phase behavior data for designing scCO[sub.2]-based extraction, impregnation, and particle formation processes involving poly(TFEMA).

Revealing structural isomerism in nanoparticles using single-crystal X-ray crystallography remains a largely unresolved task, although it has been theoretically predicted with some experimental clues. Here we report a pair of structural isomers, Au38T and Au38Q , as evidenced using electrospray ionization mass spectrometry, X-ray photoelectron spectroscopy, thermogravimetric analysis and indisputable single-crystal X-ray crystallography. The two isomers show different optical and catalytic properties, and differences in stability. In addition, the less stable Au38T can be irreversibly transformed to the more stable Au38Q at 50 °C in toluene. This work may represent an important advance in revealing structural isomerism at the nanoscale.

Chemical looping gasification (CLG) is an effective technology for efficient utilization of coal, biomass and other fuels. In this work, the detailed mechanism of catalytic decomposition during CLG for toluene, a tar model compound, was studied by using reactive force field molecular dynamics (ReaxFF MD) method. Results show that toluene hardly decomposes at temperature lower than 2000 K. Improving temperature could significantly improve decomposition efficiency but also enhances the polymerization to produce PAHs and soot precursor, with largest molecule weight of 2175 (C.sub.177H.sub.51, 3000 K, 400 ps). Fe.sub.2O.sub.3 nanocluster, as oxygen carrier, could improve the decomposition efficiency of toluene and reduce the decomposition temperature. At 2000 K and 200 ps, the catalytic conversion of toluene reaches 60%. A large amount of H.sub.2, CO, C.sub.2H.sub.2 and other small molecular gases are generated during the catalytic decomposition of toluene. At 3000 K, the yield of H.sub.2, CO and C.sub.2H.sub.2 reached 132 %mole, 117 %mole and 40 %mole of toluene, respectively. Meanwhile, polymerization reactions are largely inhibited by Fe.sub.2O.sub.3 nanocluster and the largest molecule is C.sub.20H.sub.9O, the weight of which is much lower than soot precursor in thermal decomposition. Kinetic results show that the activated energy of catalytic decomposition is about 74 kJ/mole, which is much lower than thermal decomposition (382 kJ/mole). Detailed reaction mechanism reveals that lattice oxygen on Fe.sub.2O.sub.3 nanocluster act as the active sites, which enhance the decomposition of toluene. Graphical

Chemical looping gasification (CLG) is an effective technology for efficient utilization of coal, biomass and other fuels. In this work, the detailed mechanism of catalytic decomposition during CLG for toluene, a tar model compound, was studied by using reactive force field molecular dynamics (ReaxFF MD) method. Results show that toluene hardly decomposes at temperature lower than 2000 K. Improving temperature could significantly improve decomposition efficiency but also enhances the polymerization to produce PAHs and soot precursor, with largest molecule weight of 2175 (C.sub.177H.sub.51, 3000 K, 400 ps). Fe.sub.2O.sub.3 nanocluster, as oxygen carrier, could improve the decomposition efficiency of toluene and reduce the decomposition temperature. At 2000 K and 200 ps, the catalytic conversion of toluene reaches 60%. A large amount of H.sub.2, CO, C.sub.2H.sub.2 and other small molecular gases are generated during the catalytic decomposition of toluene. At 3000 K, the yield of H.sub.2, CO and C.sub.2H.sub.2 reached 132 %mole, 117 %mole and 40 %mole of toluene, respectively. Meanwhile, polymerization reactions are largely inhibited by Fe.sub.2O.sub.3 nanocluster and the largest molecule is C.sub.20H.sub.9O, the weight of which is much lower than soot precursor in thermal decomposition. Kinetic results show that the activated energy of catalytic decomposition is about 74 kJ/mole, which is much lower than thermal decomposition (382 kJ/mole). Detailed reaction mechanism reveals that lattice oxygen on Fe.sub.2O.sub.3 nanocluster act as the active sites, which enhance the decomposition of toluene.

In this work, MOF-74 catalysts with various Co/Ni ratios obtained by hydrothermal method were prepared, and the degradation performance of various catalysts with synergistic non-thermal plasma for toluene was investigated. The addition of catalysts to NTP shown notable effects in toluene degradation and energy usage efficiency when compared to NTP alone. Notably, Co.sub.xNi.sub.y-MOF outperformed Co-MOF and Ni-MOF in terms of toluene catalytic activity. In comparison to the single plasma condition, Co.sub.2Ni.sub.3-MOF showed the maximum toluene degradation rate of 78% at the NTP discharge power of 11.66 W. SEM, BET, XRD, XPS, and FTIR were used to examine the impact of various Co/Ni ratios on the structure and redox characteristics of the samples. The interaction of Co and Ni results in many flaws and oxygen vacancies, increasing the amount of oxygen adsorbed on the surface and the reducibility of the catalyst, which is thought to be the cause of the rise in catalytic activity. Finally, based on the discovered organic compounds, the process of toluene breakdown in the plasma co-catalytic system was deduced. This work provides a novel concept for improving catalysts for the non-thermal plasma-catalyzed decomposition of toluene.

[gamma]-MnO.sub.2, [beta]-MnO.sub.2 and Mn.sub.2O.sub.3 with mesoporous structure were prepared as catalysts by using SBA-15 as hard template at different calcination temperatures. The catalysts were characterized by XRD, HRTEM, N.sub.2 adsorption-desorption, XPS, FTIR. The activity of three catalysts for catalytic ozonation of toluene followed the order of [beta]-MnO.sub.2 > [gamma]-MnO.sub.2 > Mn.sub.2O.sub.3. The results showed that the mesoporous [beta]-MnO.sub.2 exhibited the best catalytic performance because it has the highest average oxidation state of Mn and the most abundant surface adsorbed oxygen. Specifically, the toluene conversion could reach to 100% and the CO.sub.2 selectivity could reach up to 83% at 70-90 mg/m.sup.3 of toluene concentration over the catalyst. It can be inferred that reaction mechanism consists of two cycles including ozone decomposition and toluene adsorption on active sites of [beta]-MnO.sub.2, which obeys L-H mechanism. The active oxygen (O*) produced in the first cycle can oxidize the toluene molecule adsorbed in the second cycle. Simultaneously, the mesoporous [beta]-MnO.sub.2 had good stability, which reflected that it showed good performance on the catalytic ozonation of toluene during the 47-day test. In summary, this work makes it possible to remove VOCs for reality.

Tanneries are the primary source of toluene pollution in the environment and toluene due to its hazardous effects has been categorized as persistent organic pollutant. Present study was initiated to trace out metabolic fingerprints of three toluene-degrading bacteria isolated from tannery effluents of Southern Punjab. Using selective enrichment and serial dilution methods followed by biochemical, molecular and antibiotic resistance analysis, isolated bacteria were subjected to metabolomics analysis. GC–MS/LC–MS analysis of bacterial metabolites helped to identify toluene transformation products and underlying pathways. Three toluene-metabolizing bacteria identified as Bacillus paralicheniformis strain KJ-16 (IUBT4 and IUBT24) and Brevibacillus agri strain NBRC 15538 (IUBT19) were found tolerant to toluene and capable of degrading toluene. Toluene-degrading potential of these isolates was detected to be IUBT4 (10.35 ± 0.084 mg/h), IUBT19 (14.07 ± 3.14 mg/h) and IUBT24 (11.1 ± 0.282 mg/h). Results of GC–MS analysis revealed that biotransformation of toluene is accomplished not only through known metabolic routes such as toluene 3-monooxygenase (T3MO), toluene 2-monooxygenase (T2MO), toluene 4-monooxygenase (T4MO), toluene methyl monooxygenase (TOL), toluene dioxygenase (Tod), meta- and ortho-ring fission pathways. But additionally, confirmed existence of a unique metabolic pathway that involved conversion of toluene into intermediates such as cyclohexene, cyclohexane, cyclohexanone and cyclohexanol. LC–MS analysis indicated the presence of fatty acid amides, stigmine, emmotin A and 2, 2-dinitropropanol in supernatants of bacterial cultures. As the isolated bacteria transformed toluene into relatively less toxic molecules and thus can be preferably exploited for the eco-friendly remediation of toluene.

In this study, pure phase Cu.sub.2.5Mn.sub.0.5MgAl precursor was synthesized by layered double hydroxides (LDHs) precursor template method. Subsequently, Cu.sub.2.5Mn.sub.0.5MgAl-LDH is calcined at 500, 600 and 700 â to obtain the corresponding layered double oxides (LDO) catalysts for simultaneous removal of NO.sub.x and toluene. The results show that Cu.sub.2.5Mn.sub.0.5MgAl-500 exhibits the best catalytic performance in both NO.sub.x reduction and toluene oxidation reactions and the conversion of NO.sub.x and toluene can reach 85% and 88% at 210 â, respectively. XRD, SEM, BET, NH.sub.3-TPD, H.sub.2-TPR, XPS and in situ DRIFT were applied to characterize the prepared catalysts. The obtained Cu.sub.2.5Mn.sub.0.5MgAl-500 has abundant acid sites, excellent redox capacity and the highest concentration of surface Mn.sup.4+ and Cu.sup.+ species, which are considered to be the main factors determining its excellent catalytic performance. In addition, Cu.sub.2.5Mn.sub.0.5MgAl-500 shows superior durability and good tolerance to H.sub.2O/SO.sub.2.

In this study, pure phase Cu.sub.2.5Mn.sub.0.5MgAl precursor was synthesized by layered double hydroxides (LDHs) precursor template method. Subsequently, Cu.sub.2.5Mn.sub.0.5MgAl-LDH is calcined at 500, 600 and 700 â to obtain the corresponding layered double oxides (LDO) catalysts for simultaneous removal of NO.sub.x and toluene. The results show that Cu.sub.2.5Mn.sub.0.5MgAl-500 exhibits the best catalytic performance in both NO.sub.x reduction and toluene oxidation reactions and the conversion of NO.sub.x and toluene can reach 85% and 88% at 210 â, respectively. XRD, SEM, BET, NH.sub.3-TPD, H.sub.2-TPR, XPS and in situ DRIFT were applied to characterize the prepared catalysts. The obtained Cu.sub.2.5Mn.sub.0.5MgAl-500 has abundant acid sites, excellent redox capacity and the highest concentration of surface Mn.sup.4+ and Cu.sup.+ species, which are considered to be the main factors determining its excellent catalytic performance. In addition, Cu.sub.2.5Mn.sub.0.5MgAl-500 shows superior durability and good tolerance to H.sub.2O/SO.sub.2. Graphical

(R)-Benzylsuccinate is generated in anaerobic toluene degradation by the radical addition of toluene to fumarate and further degraded to benzoyl-CoA by a β-oxidation pathway. Using metabolic modules for benzoate transport and activation to benzoyl-CoA and the enzymes of benzylsuccinate β-oxidation, we established an artificial pathway for benzylsuccinate production in Escherichia coli, which is based on its degradation pathway running in reverse. Benzoate is supplied to the medium but needs to be converted to benzoyl-CoA by an uptake transporter and a benzoate-CoA ligase or CoA-transferase. In contrast, the second substrate succinate is endogenously produced from glucose under anaerobic conditions, and the constructed pathway includes a succinyl-CoA:benzylsuccinate CoA-transferase that activates it to the CoA-thioester. We present first evidence for the feasibility of this pathway and explore product yields under different growth conditions. Compared to aerobic cultures, the product yield increased more than 1000-fold in anaerobic glucose-fermenting cultures and showed further improvement under fumarate-respiring conditions. An important bottleneck to overcome appears to be product excretion, based on much higher recorded intracellular concentrations of benzylsuccinate, compared to those excreted. While no export system is known for benzylsuccinate, we observed an increased product yield after adding an unspecific mechanosensitive channel to the constructed pathway.