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Polycarbonate diols (PCDLs) are mainly used as soft segments for the synthesis of high‐performance polyurethanes. In this work, dimethyl carbonate (DMC) and aliphatic diols are selected as reactants and CH3COONa is used as a catalyst to synthesize a series of PCDLs with different structures and different molecular weights by ester exchange polymerization reaction. The chemical structures of the PCDLs are characterized by FT‐IR, 1H NMR, and 13C NMR, and the components of the distillates in the ester exchange stage are analyzed by gas chromatography. Due to the azeotropic problem of DMC and by‐product methanol during the ester exchange process, It is difficult to design and control the reactions of PCDLs to obtain the target molecular weight products. Based on the reaction process of PCDLs, we proposed a method to design and synthesize the target molecular weight of PCDLs by using the reaction molar ratio of DMC and aliphatic diols involved in the transesterification reaction, which is not affected by the conditions of transesterification reaction and is applicable to the reactions of DMC with various diols. [ABSTRACT FROM AUTHOR]

A crucial issue in analytical science and physiology is the detection of histamine with high sensitivity, specificity and credibility, which served as an important neurotransmitter in biofluids. Despite the high sensitivity of surface-enhanced Raman spectroscopy (SERS) at the level of single molecule, there are still challenges in providing high sensitivity for histamine with a small cross section. For the selective detection of histamine using SERS, a highly sensitive sandwich structure substrate combining Fe 3 O 4 and an Ag-based SERS nanotag was developed. The Fe 3 O 4 @SiO 2 –COOH served as a capture component for enriching histamine. Upon functionalized Ag nanoparticles with glycine (Gly) and (3-Aminopheyonyl) boronic acid (APBA), they were then used to connect with histamine and serve as a SERS nanotag, respectively. A linear relationship between the Raman intensity and the histamine concentration was observed over the range 10−4-10−8 M with a limit of detection of 7.24 × 10−9 M. This methodology also exhibited good selectivity in the presence of other neurotransmitters. With our new approach, histamine can be detected sensitively and reliably in fish samples, which indicates the potential prospect of an effective method for analyzing histamine in complex specimens. [Display omitted] • This strategy has a high level of specificity because the sandwich structure can only form when histamine is present. • The SERS nanotag method is highly sensitive as it eliminates the difficulties associated with histamine Raman detection. • With the introduction of Fe 3 O 4 , histamine separation and analysis can be performed very quickly and efficiently. [ABSTRACT FROM AUTHOR]

A facile and sensitive glucose sandwich assay using surface-enhanced Raman scattering (SERS) has been developed. Glucose was captured by 3-aminopheyonyl boronic acid (APBA) modified Ag nanoparticles decorated onto a polyamide surface. Then, Ag nanoparticles modified with 3-amino-6-ethynylpicolinonitrile (AEPO) and APBA were used as SERS tags. APBA forms specific cis-diol compounds with glucose molecules avoiding interference by other saccharides and biomolecules in urine enabling its selective detection. As the actual Raman reporter, AEPO exhibited a distinctive SERS peak in the Raman silent region, thus increasing the sensitivity of the glucose detection to 10−11 M. Additionally, the developed SERS assay was reusable, and its applicability in artificial urine samples demonstrated future clinical utility confirming the potential of this innovative technology as a diagnostic tool for glucose sensing. [ABSTRACT FROM AUTHOR]

In this work, the effect of ethanol co-feeding in the synthesis of higher alcohols from syngas over K-MoS2 catalyst was investigated in a batch reactor, and the yield of higher alcohols was improved. K-MoS2 prepared with thiourea as a sulfur source exhibited better performance for synthesizing higher alcohols from syngas due to its more stacking layers, higher specific surface area and more Mo4+ active species. Ethanol co-feeding could provide more alkyl intermediate species, which was conducive to the insertion of CO, thereby promoting the conversion of CO and the production of higher alcohols. A change in the reaction path from insertion of CO to homocoupling of ethanol was found upon increasing the ethanol to CO ratio. Higher alcohols production was maximized with the side products in an acceptable range for n EtOH/n CO = 0.3. [ABSTRACT FROM AUTHOR]

The influence of n‐propanol co‐feeding in isobutanol synthesis from syngas was investigated over K‐CuMgCe catalyst in a batch reactor. After the addition of n‐propanol, the selectivity of isobutanol increased significantly. Moreover, it was different from the traditional fixed bed after adding alcohol, which was negative or had no significant impact on CO conversion. The CO conversion was increased significantly after the addition of n‐propanol under the system conditions. It might be due to the back‐mixing in the slurry bed, which increased the residence time of intermediate species on the catalyst surface. The consumption of C1 species from syngas through aldol condensation led to a shift in methanol equilibrium and a significant increase in CO conversion. As the ratio of n‐propanol to CO increased, the reaction path changed from the aldol condensation of C1 species with n‐propanol to the self‐coupling of n‐propanol. CO conversion reached 63.5 % and isobutanol selectivity reached the maximum of 28.2 % within a tolerable range of byproducts for n n‐propanol/n CO=0.5. Excess of n‐propanol would reduce isobutanol yield and was not conducive to CO conversion. [ABSTRACT FROM AUTHOR]

For the purpose of investigating the chemical enhancement of amorphous semiconductors as well as increasing the sensitivity of the surface-enhanced Raman spectroscopy (SERS) substrate, titanium dioxide (TiO2) precursors were calcined at different temperatures to generate crystallized TiO2 (c-TiO2) and amorphous TiO2 (a-TiO2) nanosheets, respectively. Afterward, a two-dimensional (2D) a-TiO2/Ag nanosheet SERS substrate was successfully fabricated using electrostatic interaction between a-TiO2 and Ag nanoparticles. In order to demonstrate a greater SERS sensitivity on a-TiO2/Ag compared to either c-TiO2 or Ag nanoparticles alone, the SERS probe molecules rhodamine 6G (R6G) and malachite green (MG) were utilized. Based on the results of SERS detections for probe molecules and contaminants, it demonstrates that a-TiO2/Ag nanosheets produce highly sensitive and repeatable Raman signals. The detectable concentration limits for R6G and MG were found to be 10−11 M and 10–10 M, respectively. And it has been determined that the system exhibits an enhancement factor (EF) of up to 1 × 108. The limit of detection for 4-mercaptobenzoic acid and alizarin red can both reach 1 × 10–8. Furthermore, a finite-difference time-domain simulation is performed in order to evaluate the magnetic field strength generated by Ag nanoparticles. As a result of the simulation, it is evident that the actual EF is smaller than the calculated one, leading support to the view that a-TiO2 nanosheets have a beneficial effect on the chemical enhancement of SERS. [ABSTRACT FROM AUTHOR]

Sulfonated mesoporous polydivinylbenzene was prepared by different sulfonation methods and then as a solid acid to catalyze the condensation of phenol and cyclohexanone. The physicochemical properties of the solid acid were characterized by BET, FT-IR, SEM, TG, XRD and acid–base titration; then, the structure–activity relationship of the solid acid was studied. It was found that the catalyst had a sponge like microstructure with the specific surface area of 395 m2/g and average pore diameter of 14.1 nm. The acid–base titration result showed that the acid density of mesoporous polydivinylbenzene solid acid prepared by double sulfonation (D-SPDVB) was the highest, reaching 4.62 mmol H+/g. The catalytic result showed that D-SPDVB had better catalytic performance than Amberlyst-15, sulfuric acid and other traditional Brønsted acids due to its high acid density and suitable pore structure. More importantly, D-SPDVB had good stability, and its catalytic performance did not decrease significantly after reused 5 times. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights: • The functional group of C 60 derivatives affected the chemical state of Ni and Pd. • Pd promoted the reduction of Ni by H 2 under mild conditions via hydrogen spillover. • Pd-Ni-N-C 60 exhibited excellent catalytic performance for the synergistic effect. • Reaction rate of 36.7 mol NB/(mol metal·min) was obtained under 70 °C and 1.0 MPa H 2. Abstract Pd promoted Ni supported on C 60 derivative was prepared and employed to catalyze the hydrogenation of nitrobenzene (NB). The effects of the function groups of C 60 derivatives and Pd on the catalytic performance of Ni-based catalyst were investigated. The characterizations illustrated that the function groups of C 60 derivatives significantly affected the chemical state of Ni and Pd, which resulted in different catalytic performance. In addition, Pd as a promoter promoted the in-situ reduction of Ni under mild conditions via hydrogen spillover. Pd-Ni-N-C 60 , derived from C 60 -ethanediamine derivative with the molar ratio of Ni to Pd of 6:1, exhibited excellent catalytic performance. The high surface contents of Pd0, electron-rich Ni species and the synergistic effect between Pd, Ni and C 60 -ethanediamine were responsible for the outstanding catalytic performance. Under 70 °C and 1.0 MPa of H 2 , the nitrobenzene conversation of 98.0% and the aniline selectivity of 98.2% were obtained over Pd-6Ni-N-C 60 with the reaction rate of 36.7 mol NB/(mol metal·min). The H 2 pressure in the range of 0.1 MPa and 0.8 MPa obviously affected the aniline selectivity at 90 °C. [ABSTRACT FROM AUTHOR]

A series of bio-based copolyesters, poly(ethylene 2,5-furandicarboxylate-co-ethylene 1,4-cyclohexanedicarboxylate)s (PEFCs) were synthesized from ethylene glycol (EG), 2,5-furandicarboxylic acid (FDCA) and 1,4-cyclohexanedicarboxylic acid (CHDA) through a two-step melt polycondensation procedure. The chemical structure, compositions and sequence distributions were determined by 1 H NMR. The molecular weight, thermal properties, thermal stabilities, crystal structure and mechanical properties were investigated by GPC, DSC, TGA, WAXD, and tensile testing, respectively. All PEFCs showed the characteristic of random copolymer, and their composition could be controlled by the feed molar ratio of FDCA to CHDA. DSC results showed that PEFCs were amorphous, while increasing the content of the CHDA unit, the glass transition temperatures (Tg) of PEFCs decreased. Moreover, the thermal stabilities of all PEFCs remained unchanged. The tensile testing demonstrated that PEFC-30 was a toughened plastic with tensile modulus 801 MPa and elongation 667%. [ABSTRACT FROM AUTHOR]

Abstract: CuZnO catalysts were prepared by different methods, characterized by applying a combination of techniques, and the effect of preparation method on the structure and the catalytic performance for syngas hydrogenation at low temperature in liquid phase was investigated. The results showed that due to the difference of the interaction between Cu and Zn, the preparation method greatly affected the crystallinity of CuZnO. The crystallinity of CuZnO had a direct relation with the CO adsorption property. The total CO adsorption amount determined the catalytic activity, the weak adsorption of CO accounted for the methanol synthesis, while the strong adsorption of CO accounted for the ethanol synthesis. CuZnO prepared by the homogeneous precipitation with the lowest crystallinity exhibited the highest total carbon conversion of 68.6% with the methanol selectivity of 84.9%, while CuZnO prepared by the sol gel with the highest crystallinity exhibited the highest ethanol selectivity of 47.6%.Graphical Abstract: The preparation method of CuZnO had a significant effect on the CO adsorption property and then resulted in a substantial modification in the product distribution for the syngas hydrogenation at low temperature in liquid phase. The catalytic activity was determined by the total amount of CO adsorption, the weak CO adsorption accounted for the methanol synthesis and the strong CO adsorption accounted for the ethanol synthesis. [ABSTRACT FROM AUTHOR]

Copolymer carbonate was synthesized from diphenyl carbonate (DPC), 9, 9‐bis [3‐phenyl‐4 ‐(2‐hydroxyethoxy) phenyl] fluorene (BPPEF) and 2,2′ ‐bis (2‐hydroxy‐ethoxy)‐1,1′ ‐binaphthalene (BHEBN) by melt transesterification. The composition and random structure of the copolymer were determined by FT‐IR, 1H NMR and 13C NMR analysis. DSC and TGA analysis showed that Cardo structure could significantly increase the glass transition temperature and thermal decomposition temperature. With the addition of BHEBN, the refractive index of copolymer was increased, but the thermal properties of copolymer were decreased. It is found that the contribution of naphthalene structure to the refractive index of the polymer material is higher than that of benzene structure. When the dosage of BHEBN is 42 mol %, the glass transition temperature (Tg) of the copolymer is 141.8 °C, the maximum thermal decomposition temperature is 421.9 °C, the refractive index is 1.6535, the Abbe number is 21, the transmittance is 88.29 %, and the birefringence is negative 0.01×10−3. [ABSTRACT FROM AUTHOR]

The disproportionation of methyl phenyl carbonate (MPC) to synthesize diphenyl carbonate (DPC) catalyzed by organo-titanium compounds with different coordination groups was systematically investigated. The results of the molecular structure analysis, the catalytic performance evaluation and the chemical computational studies revealed that both the electron effect and steric hindrance of the coordination groups together affected the active Ti center and therefore influenced the catalytic performance of the catalysts. The influence of the electron effect was more important than the steric hindrance. The catalytic activity is in the order of Ti(O- i C 3 H 7 ) 4 > Ti(OC 6 H 5 ) 4 > Ti(OC 4 H 9 ) 4 > TiO(OOCCH 3 ) 2 > TiO(acac) 2 > Cp 2 TiCl 2 , and Ti(O- i C 3 H 7 ) 4 exhibited the best catalytic performance, due to its appropriate steric hindrance and electron effect for the coordination group. Under the optimum condition (n(Cat.)/n(MPC) = 0.04, reacted at 180 °C for 3 h), the MPC conversion of 90.4% and DPC selectivity of 99.6% were attained, respectively, which are comparable to those of other catalysts reported. Moreover, the catalyst is low cost, non-toxic and easily obtained by readily commercial-available purchase, and this catalytic system is also easy operation and convenient-controllable, indicating that it is conducive to future industrial application. In addition, a possible reaction mechanism catalyzed by the organo-titanium compounds with Lewis acid was also proposed for the process. [ABSTRACT FROM AUTHOR]

Copolycarbonate was synthesized by melt transesterification method, using diphenyl carbonate, isosorbide and 1,4-cyclohexanedimethanol (CHDM) as raw materials. The copolymer composition and random structure of the copolymer were determined by Fourier transform infrared and 1H NMR analysis. The DSC and TGA analysis showed that CHDM was introduced into the isosorbide polycarbonate chain, which effectively lowered the glass transition temperature of the polymer without lowering the thermal decomposition temperature. The glass transition temperature of the copolymer can be controlled by the addition amount of CHDM, and its processing performance can be improved. In addition, the introduction of CHDM did not reduce the high light transmittance (> 91.5%) of isosorbide polycarbonate. With the gradual increase of the amount of CHDM added, the refractive index of the copolymer decreases slightly. When the CHDM content is 30 mol%, the glass transition temperature (Tg)of the copolymer is 132.2 °C, the thermal decomposition temperature is > 350 °C, the refractive index is 1.4960, the Abbe number is 51, and the transmittance is 91.6%, and the haze is 1.07%. [ABSTRACT FROM AUTHOR]

Solid alkali KF/MgO catalysts were prepared using the impregnation method by combining alkali metal compounds with oxides, which performed the transesterification of isosorbide (IS) with dimethyl carbonate (DMC) into dicarboxymethyl isosorbide (DC). Characterization of the catalysts was conducted through X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and N2 adsorption–desorption analysis. The catalytic performance of KF/MgO was examined under diverse KF loading and calcination temperature conditions. The characterization of catalyst identified that the creation of innovative active components K2MgF4 and K2CO3 were produced at a calcination temperature of 500 ℃ and a KF loading amount of 40%. The catalyst of 40-KF/MgO-500 demonstrated the most effective, favourable activity and selectivity. Through the optimization of transesterification process conditions, it was discovered that the yield of DC was at its highest under the optimal reaction conditions of n(DMC)/n(IS) = 6.5, catalyst dosage of 0.21 wt% (relative to IS mass), transesterification temperature of 120 °C, and reaction time of 6 h. [ABSTRACT FROM AUTHOR]

Four types of alkali metals Li, Na, K and Cs carbonate doped CuMgCe catalysts were prepared by an incipient wetness impregnation method, and the effect of alkali metals doping on the catalytic performance of catalyst for isobutanol synthesis from syngas was studied. Only the doping of K and Cs improved isobutanol selectivity, and the catalytic performance of K-CMC was better. All the catalysts characterized by XRD, BET, SEM, TEM, XPS, H 2 -TPR, CO-TPD, CO 2 -TPD and NH 3 -TPD to further reveal the effect of alkali metals on catalysts for isobutanol synthesis. We found that the alkali metals doping reduced the reducibility of the catalysts, but increased the strength and density of basic sites and reduced the density of acidic sites, thereby leading to diverse catalytic performance of the catalysts for isobutanol synthesis. Compared with K-CMC, the insufficient performance of Cs-CMC was attributed to CO 2 oxidation of Cu and CO 2 neutralization of basic sites. [Display omitted] • Varied alkali metals doping CuMgCe catalysts for isobutanol synthesis from syngas. • Alkali metals doping decreased the reducibility of catalyst, thereby reduced CO conversion. • More basic sites and fewer acidic sites on the catalyst after alkali metals doping promoted isobutanol synthesis. • The insufficient performance of Cs-CMC was attributed to CO 2 oxidation of Cu and CO 2 neutralization of basic sites. [ABSTRACT FROM AUTHOR]

In this study, silica-gel (SG)-supported deep eutectic solvent (DES) with a different loading dosage as the novel nanocomposite materials has been synthesized by sol–gel method. And the supported nanocomposite materials were used as the catalyst for the synthesis of 1,10-phenanthroline from the 8-aminoquinoline and acrolein. The properties and structure of catalysts were characterized by Fourier transform infrared, N2 adsorption–desorption, scanning electron microscopy, thermogravimetric analysis and elemental analysis techniques. It was found that the 12%DES/SG catalyst with the best catalytic activity possessed the suitable specific surface area 132 m2/g and 12% loading amount of DES, which combines the excellent properties of mesoporous materials and DES. The result of thermogravimetric analysis was exhibited that the nanocomposite materials could not be decomposed below 240 °C, which can be used as a stable catalytic material under reaction conditions. Furthermore, the effect of reaction parameters such as reaction temperature and catalyst amount, molar ratio of 8-aminoquinoline and acrolein and reaction time was also studied. Under the optimal process parameters, within the optimum parameters: 130 °C, acrolein: 8-AQ = 2:1, catalyst amount 20 wt%, and time 4 h, the conversion of 8-aminoquinoline and selectivity of 1,10-phenanthroline were 83.8% and 84.3%, respectively. Otherwise, the catalyst can be separated from the reaction system and reused. Therefore, the silica-gel-supported deep eutectic solvent nanocomposite materials can be considered as a potential catalytic material for the synthesis of 1,10-phenanthroline and other nitrogen-containing heterocyclic organic chemical intermediates. Replacing traditional sulfuric acid and hydrochloric acid with silica-gel-supported deep eutectic solvents as new nanocomposite catalysts provides a more efficient, greener and more economical strategy for the synthesis of 1,10-phenanthroline. [ABSTRACT FROM AUTHOR]

Understanding the ionic transport behaviors in hybrid solid electrolytes (HSEs) is critically important for the practical realization of rechargeable Li‐metal batteries (LMBs) with high safety. Herein, it is reported a new solid "Ionogel‐in‐Ceramic" electrolyte by using the Li1.3Al0.3Ti1.7(PO4)3 (LATP) ceramic particles as a framework and "Poly(ionic liquid)s‐in‐Salt" ("PolyIL‐in‐Salt") ionogel as an ionic bridge via a simple pressing process. The "PolyIL‐in‐Salt" ionogel precursor is designed to improve the chemical compatibility at solid–solid interfaces. Molecular dynamics simulations reveal the roles of salt concentrations on the distribution of co‐coordination of "PolyIL‐in‐Salt" ionogel. Moreover, the "PolyIL‐in‐Salt" ionogel containing co‐coordination not only inhibits the parasitic reactions between LATP and Li anode but also provides efficient Li+ conducting pathways. Benefiting from the designed structure, the "Ionogel‐in‐Ceramic" HSE exhibits an excellent ionic conductivity of 0.17 mS cm−1 at 50 °C. Meanwhile, the as‐formed solid electrolyte enables a long cycle of over 3500 h in Li/Li symmetric cell. Further, all‐solid‐state lithium metal batteries fabricated on LiFePO4 and high voltage LiCoO2 cathodes deliver 160.0 mAh g−1, 125.0 mAh g−1, respectively. This study sheds light on the rational design of solid‐state electrolytes with efficient interparticle Li+ conduction, compatible, stable, compact, and durable electrode–electrolyte interfaces. [ABSTRACT FROM AUTHOR]

For acid‐catalyzed chemical reactions with forming isomers of the target product, the isomer by‐products cannot be well inhibited only by adjusting the acid properties. At this point, it is an effective strategy to design functional acid catalysts to decrease by‐products through increasing the steric hindrance of forming isomer by‐products. In this paper, thiol and trifluoromethanesulfonyl functional sulfonated mesoporous polydivinylbenzene solid acids were prepared. The Bisphenol‐A synthesis reaction was used as a probe reaction to verify the cooperative effect of thiol and trifluoromethanesulfonyl on the catalytic performance of prepared solid acids. The results confirmed that thiol functionalizing sulfonated mesoporous polydivinylbenzene solid acid could reduce the by‐product o′p‐bisphenol‐A through steric hindrance effect and then improved the selectivity of the target product p′p‐bisphenol‐A. Trifluoromethanesulfonyl functionalizing sulfonated mesoporous polydivinylbenzene could promote the catalytic efficiency and the selectivity of p′p‐bisphenol‐A by enhancing the acidity of solid acids. Thiol and trifluoromethanesulfonyl difunctional sulfonated mesoporous polydivinylbenzene (PDVB‐SO2CF3‐SO3H‐SH) had the optimal catalytic performance due to the cooperative effect of steric hindrance and strong acidity. The phenol conversion of 37 % and the p′p‐bisphenol‐A selectivity of 97 % were obtained over PDVB‐SO2CF3‐SO3H‐SH under 90 °C for 4 h. [ABSTRACT FROM AUTHOR]

A new copolyesters of poly(2-[4-(2-hydroxyethoxy)phenoxy]ethyl-co-1,4-cyclohexylenedimethylene terephthalate) (PHCT) with different compositions were synthesized from terephthalic acid, 1,4-cyclohexanedimethanol and hydroquinone bis(2-hydroxyethyl) ether (HQEE) via esterification-polycondensation reaction. The synthesized copolyesters were analyzed by 1H-NMR, FT-IR, GPC, intrinsic viscosity, DSC, TGA and tensile testing, respectively. The 1H-NMR and FT-IR analysis confirm the successful introduction of HQEE into poly(1,4-cyclohexylenedimethylene terephthalate (PCT) chains. The introduction of HQEE into PCT chains can effectively lower the melting point of PCT, making it easier to process. The glass transition temperature of PHCT is higher than 70 ℃ and it has the comparable thermal stabilities to PCT. In addition, introducing HQEE into PCT chains can effectively improve the molecular weights of PCT, thus imparting PHCT with better mechanical performance relative to PCT. The PHCT is a tough polymer, which owns the higher Young's modulus (above 300 MPa), the higher tensile strength (above 39 MPa) and the higher elongation at break (above 226%). [ABSTRACT FROM AUTHOR]

A new copolyesters of poly(1,4-cyclohexylenedimethylene terephthalate-co-4,4'-biphenydicarboxylate) (PCTB) with different compositions were synthesized from terephthalic acid, 1,4-cyclohexanedimethanol and 4,4'-biphenyldicarboxylic acid (BDA) via esterification-polycondensation reaction. The synthesized copolyesters were analyzed by 1H-NMR, 13C-NMR, FT-IR, GPC, intrinsic viscosity, DSC, TGA and tensile testing, respectively. The 1H-NMR, 13C-NMR and FT-IR results verify the successful introduction of BDA into poly(1,4-cyclohexylenedimethylene terephthalate (PCT) chains. The introduction of BDA into PCT chains can effectively lower the melting point of PCT, making it easier to process. The glass transition temperature of PCTB is higher than 103 °C and its thermal stability is better than that of PCT. The rheological tests confirm the enhanced melting stability of PCT after introducing BDA into PCT chains. Furthermore, the PCTB, which owns the comparable mechanical properties to PCT, is a tough polymer with the higher Young's modulus (above 230 MPa), the higher tensile strength (above 41 MPa) and the higher elongation at break (above 159%). [ABSTRACT FROM AUTHOR]

Diphenyl carbonate is a versatile chemical intermediate and key building block for the synthesis of polycarbonates. A facile route to prepare PbZr nanocomposites were developed using different precipitants to investigate the effect on the catalytic activity of the solid acid catalysts. The structure–performance relationship of the nanocomposites, dispersion of active components and structure stability, and the catalytic performance were thoroughly analyzed. The results showed that there existed the interaction between Zr and Pb, which induced the homogenous dispersion of Pb and high surface acid sites that could enhance the catalytic activities. Among the catalysts, PbZr–NH4OH represented the best catalytic performance and superior stability, indicating that NH4OH was more favorable compared with sodium hydroxide, ammonium carbonate and urea. The research provides a valuable reference in a wide range application of nanocomposite preparation for the effective and clean production of various carbonates. [ABSTRACT FROM AUTHOR]

Abstract: The flocculation kinetics of kaolin particles suspended in 0.01mol/L NaCl solution and adsorption properties of cationic starch on kaolin surface have been investigated at pH 5.0. Adsorption kinetics of cationic starch followed pseudo-second-order model (R 2 >0.98). Flocculation kinetics showed that increase in flocculant dosage resulted in higher rate constants for the flocculation process and lower rate constant for the aggregate breakage. The rate of aggregation of particles and frequency of collisions of particles are very slow and the two steps determined the rate of flocculation process. The adsorption of cationic starch on the kaolin surface followed Langmuir isotherm (R 2 >0.99). Thermodynamic study indicated that the values of ΔG θ were strongly temperature-dependent and that cationic starch adsorption onto kaolin particles entropically dominated rather than enthalpically driven since |ΔH θ |<|−TΔS θ |. The negative values of ΔG θ and the positive values of ΔH θ suggested that the adsorption process is spontaneous and endothermic. The value of ΔH θ (37.262kJ/mol) suggested that the electrostatic interaction is the dominant mechanism for the adsorption of cationic starch on kaolin. The fractional coverage decreased with increasing temperature, consistent with a reduced hydrodynamic diameter and a more contracted polymer conformation. [Copyright &y& Elsevier]

Abstract: The adsorption of carboxymethyl starch (CMS) at the α-alumina/aqueous solution interface has been investigated through adsorption studies, electrokinetics mobility measurements, and FTIR spectroscopy. Zeta potential measurements show that the addition of CMS results in a more dramatic increase in the absolute zeta potential in the alkaline region, as well as a shift of the isoelectric point to lower values, indicating the adsorption of CMS from the aqueous solution onto the alumina surface. The positive hydrophilic surface sites of alumina are responsible for the adsorption of CMS molecules. The adsorption of CMS is possible after charge reversal by the addition of excess CMS. Nearly 30 min of contact time are found to be sufficient for the adsorption of CMS to reach equilibrium. CMS adsorption follows a Langmuir isotherm with adsorption capacities of 91.74 mg CMS per gram of α-alumina. For the adsorption of CMS, pseudo-second-order chemical reaction kinetics provides the best correlation with the experimental data. FTIR analysis indicated that CMS forms outer complexes with alumina surfaces depending on the shifting of the asymmetric and symmetric bands. [Copyright &y& Elsevier]

A novel La modified copper phyllosilicate nanotubes (Cu-PSNT) were designed for hydrogenation of methyl acetate (MA) to ethanol. La/Cu-PSNT catalysts were prepared by the focus on the formation of unique tubular structure and evolution of copper species by varying La loading. The physicochemical properties and distribution of the copper species were systematically studied through several characterizations. The results showed that the Cu-PSNTs catalyst exhibited superior catalytic activity in comparison with the catalyst prepared by traditional ammonia-evaporation (AE method). Moreover, the addition of La greatly influenced the dispersion of active copper species and the ratio of Cu0/(Cu0 + Cu+) through the strong interplay between copper and lanthanum species. An appropriate amount of La could increase the surface area of active copper and enhance the ability to dissociate H2 on La/Cu-PSNT catalyst, which were essential to increase the activity and stability in this hydrogenation reaction. Novel copper phyllosilicate nanotubes (Cu-PSNT) was fabricated used the hydrothermal method for hydrogenation of methyl acetate to ethanol. The nano-socketed catalyst was felicitously adjusted by doping La. The obtained the 3La/Cu-PSNT catalyst exhibited a high and stable hydrogenation ability due to its proper distribution of copper valence. [ABSTRACT FROM AUTHOR]

In this study, three different choline chloride-based deep eutectic solvents were synthesized. And it is the first time to synthesize 1,10-phenanthroline through an improved Skraup reaction using deep eutectic solvent as the new catalyst from acrolein and 8-aminoquinoline. The deep eutectic solvents were characterized by Fourier transform infrared (FT-IR), 1H nuclear magnetic resonance (1H NMR), pH/mV meter, and thermogravimetric analysis (TGA). The research results show that the deep eutectic solvent formed by sulfanilic acid and choline chloride has the strongest acidity and highest catalytic active among the three deep eutectic solvents. Besides, the impacts of reaction parameters and molar ratio of raw materials on the reaction were also investigated. Under the optimized reaction conditions, the maximum selectivity and yield of 1,10-phenanthroline were achieved as 84.6 and 75.6%, respectively. The synthesis method, meanwhile, also has simple preparation process and low cheaper catalyst raw. Replacing traditional sulfuric acid and hydrochloric acid with deep eutectic solvents (DESs) as new catalysts provides a more efficient, greener and more economical strategy for the synthesis of 1,10-phenanthroline by a new improved Skraup reaction. [ABSTRACT FROM AUTHOR]

Dimethyl carbonate (DMC) is well known as an extremely industrially valuable substance. The demand for high-efficiency synthesis of DMC has greatly driven the exploration of novel catalysts and their low-cost preparation methods. Herein, a novel method for the rapid batch preparation of CaO/carbon catalysts using calcium citrate (CaCi) was provided, and these catalysts were used to catalyze the transesterification reaction of methanol and ethylene carbonate (EC) to synthesize DMC and ethylene glycol (EG). Accordingly, the structure and properties of the catalysts were characterized using XRD, FTIR, N2 adsorption–desorption, TG, TG-IR, CO2-TPD, XPS, SEM, TEM and ICP-OES techniques. Meanwhile, the effect of various process conditions such as carbonization temperature, reaction temperature, reaction time and catalyst amount has been extensively evaluated. Under the optimal process parameters, the conversion of EC and the selectivity of DMC and EG were 81.2, 99.3 and 99.5%, while the turnover number (TON) and turnover frequency (TOF) were 54.1 and 162 h−1, respectively. Furthermore, kinetic analysis was carried out, and the value of k (reaction rate constant) was ≈0.159 mol L−1 min−1. The reusability was also investigated. [ABSTRACT FROM AUTHOR]

Mg–Al hydrotalcites were prepared by the forward, reverse and simultaneous titration coprecipitation methods, respectively. The effects of coprecipitation method on Mg–Al hydrotalcite properties were investigated. The resulting catalysts were evaluated for their performance in the synthesis of diethylene glycol di-(methyl carbonate). The results showed that there were no other crystalline phases, but a Mg–Al hydrotalcite structure in any of the samples and HTS prepared by the simultaneous titration method had the best crystallinity. Only the Mg–Al hydrotalcites prepared by the forward and simultaneous titration coprecipitation methods had a similar Mg/Al ratio as with the salt solution. The coprecipitation method affected the pore structure, specific surface area and basicity distribution of Mg–Al hydrotalcite and thus affected its catalytic performance. HTS, which had a relatively small pore size, moderate specific surface area and considerable basicity, displayed superior catalytic performance (91.6% yield) under optimized conditions. The catalyst could be easily separated and reused. Its activity did not decrease apparently, and the yield of target product maintained around 90% after five circles. [ABSTRACT FROM AUTHOR]

Ru–carbon catalysts with different physical morphologies and chemical states of Ru were prepared by different methods and used to catalyze the hydrolytic hydrogenation of cellulose at high temperatures. The physical morphology of Ru particles and the chemical state of Ru significantly influenced the catalytic performance. The Ru nanoparticles in Ru@MC prepared by the in situ carbothermal reduction method exhibited a special chemical state due to the strong interaction with carbon. The special structure could not only prevent the growth of Ru particles but also enhance the hydrogen spillover effect and improve the hydrogenation efficiency. Among the Ru–carbon catalysts, Ru@MC showed the best catalytic performance with a 72.4% yield of sorbitol. Furthermore, the embedded structure of Ru@MC stabilized the Ru nanoparticles, and the catalyst could be reused at least 6 times. [ABSTRACT FROM AUTHOR]

The selective conversion of cellulose to sorbitol is a promising route to valorize biomass. A binary catalyst ZrP-Ru/MC was constructed by mesoporous carbon supported ruthenium (Ru/MC) combined with zirconium phosphate (ZrP). It was found that ZrP-Ru/MC was an excellent catalyst for the conversion of cellulose with high sorbitol yield. Under the optimal reaction condition, a high sorbitol yield of 66.4% was obtained in just 1.5 h if cellulose was mix-milled together with ZrP. The characterizations results indicated that the high dispersion of Ru and macroporous–mesoporous structure were the key factor to determine the excellent catalytic activity of Ru/MC. In addition, the Ru TOF of 220 h−1 in the Ru/MC was much higher than that of commercial ruthenium carbon, indicating the high Ru utilization in Ru/MC. [ABSTRACT FROM AUTHOR]

Dimethyl carbonate (DMC) is an important environmentally‐friendly organic compound. The need for efficient synthesis of DMC has given a fillip to search for new catalysts and their cost‐effective preparation. In this work, a series of KAlO2/γ‐Al2O3 heterogeneous catalysts were rapidly prepared by impregnation method. These catalysts were characterized by FTIR, XRD, XPS, TG‐MS, ICP‐OES, BET and Hammett acid‐base titration and tested for the synthesis of DMC via transesterification from ethylene carbonate (EC) with methanol. The results demonstrated that KAlO2, as the active species, was produced in large quantities during the calcination process. The catalyst with a calcination temperature of 700 °C and a K2CO3 loading of 45 wt % exhibited the best catalytic activity. The optimum conditions for the process resulted in a catalyst amount of 1.0 wt %, a reaction temperature of 100 °C and a reaction time of 80 min, in which the EC conversion and DMC selectivity were 80.2 % and 98.9 %, respectively. In addition, the TON, TOF and reaction rate were 80.3, 61.2 h−1 and 3.91 gDMC⋅gcat−1⋅min−1. The reusability of the catalyst with best catalytic activity was also studied. [ABSTRACT FROM AUTHOR]

A carbonaceous solid acid catalyst obtained from by‐products of sorbitol dehydration process, was prepared via facile one‐step carbonization and sulfonation method. The results of various characterization technologies showed that as‐prepared acidic carbon bearing ‐SO3H, ‐COOH and ‐OH groups with Brønsted acid sites was effective for solvent‐free dehydration of sorbitol to produce isosorbide. Full complete sorbitol conversion with 72.1% isosorbide yield was achieved at 170 °C after 2 h reaction. Catalyst could be used for three cycles retaining the most of its initial catalytic activity. Importantly, the catalyst and reaction by‐products in this process could be easily recycled and facilely utilized, offering sustainable process in production of isosorbide from sorbitol. [ABSTRACT FROM AUTHOR]

The transformation of ethanol into high‐value‐added products has attracted considerable attention. Diethyl carbonate (DEC) is an important organic carbonate, and widely used as lithium battery electrolyte, fuel additive. et al. In this study, DEC is synthesized by oxidative carbonylation of ethanol using metal halide‐Ionic liquids (ILs) as the catalyst. And it is found that CuCl2‐[BMIm]BF4 shows higher catalytic performance which is attributed to the synergistic effect of the Brønsted and Lewis acid sites. Under the optimized conditions of nIL/nCuCl2=1.5:1, T=120 °C, P=4.0 MPa, PCO/PO2=9:1, and reaction time 2 h, the conversion of ethanol and selectivity of DEC were 38.8% and 99.7% respectively, which is the highest reported for the synthesis of DEC by oxidative carbonylation under similar reaction conditions. Moreover, the CuCl2‐[BMIm]BF4 catalyst has the advantages of good stability and reusability which was reused seven times without obviously decrease in the catalytic activity. Besides, the corrosion rate and inhibition efficiencies on stainless steel are 0.004 mm/a and 92% with CuCl2‐[BMIm]BF4 catalyst. [ABSTRACT FROM AUTHOR]

Titanates are frequently used as precursors to prepare transesterification catalysts with TiIV species. Unfortunately, it is challenging to control the dispersity of TiIV active sites on supports. Herein, a series of TiIV species is anchored on abundant linker vacancy sites by introducing point and large scale defects in UiO-66(Zr/Ti) with hierarchical-pore structure. The catalyst functionalized by titanium(IV) oxide bis(2,4-pentanedionate) shows excellent catalytic performance in the transesterification of dimethyl carbonate with phenyl acetate. The catalysts are characterized by XRD, FT-IR, N2 adsorption–desorption, XPS, SEM and STEM-HAADF techniques. The results demonstrate that the delicate mesopores in the support can not only exhibit a large surface area for the distribution of the active sites, but also provide better mass transfer performance. Meanwhile, the introduction of octahedral TiIV ions raises the activity of the catalyst via more coordinatively unsaturated ZrIV sites. Furthermore, using titanium(IV) oxide bis(2,4-pentanedionate) as a Ti source can effectively prevent the condensation of tetrahedral TiIV species anchored on the hierarchical-pore UiO-66(Zr/Ti) support. [ABSTRACT FROM AUTHOR]

The catalysts containing tetra-coordinated titanium have been widely used for transesterification. The key issue in the design of these catalysts is the stability of tetra-coordinated titanium. In this study, mesoporous amorphous titanium oxides coated on a zeolitic imidazolate framework (ZIF-8) were developed by using a hexadecylamine (HDA) surfactant as a structure-directing agent. The mesopores surface areas of the amorphous TiO2 shell could be simply controlled by changing the dosage of HDA in the synthetic process. The novel, efficient and recyclable heterogeneous catalyst was introduced to the synthesis of diphenyl carbonate from dimethyl carbonate and phenyl acetate for the first time. The catalyst structure was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption–desorption, Fourier transform infrared spectroscopy and thermogravimetric analysis. The effects of the molar ratio of Ti to Zn, HDA amount, catalyst amount, reaction time and reusability on the yield of the transesterification products were also determined. The results showed that the mesopores of TiO2 shell facilitated reactants and productions diffusion to increase the conversion of phenyl acetate and yield of diphenyl carbonate. Moreover, the coordination between titanium and ZIF-8 also endowed the catalysts with reasonable reusability. [ABSTRACT FROM AUTHOR]

• PISBFs were prepared from 2,5-dimethylfuran dicarboxylate, isosorbide and butanediol. • PISBFs had T D,5% values higher than 370 °C and T DM higher than 405 °C. • PIS 40 B 60 F had a Tg 87 °C, a Young's modulus 1400 MPa and an elongation at break 173%. Fully biobased copolyesters poly(isosorbide- co -butylene 2,5-furandicarboxylate) (PISBF) were synthesized from 2,5-dimethylfuran dicarboxylate (DMFD), isosorbide (IS) and 1,4-butanediol (BDO) via transesterification and polycondensation reactions. The resulting copolymers were characterized by 1H NMR, 13C NMR, GPC, intrinsic viscosity, DSC, TGA and tensile testing, respectively. The NMR characterizations had confirmed that BDO was successfully introduced into the poly(isosorbide 2,5-furandicarboxylate) (PIF) polyester chains. Over the IS experimental composition range 20–80 % in copolymer chains, PISBF copolymers had T D, 5% values higher than 370 °C and T DM higher than 405 ° C, and Tg values within the range of 55 °C and 150 °C. Introduction of BDO units into PIF chains imparted the PISBF copolyester with better mechanical performance than PIF, thus PISBF copolyesters with IS content of 20–50% were strong and toughened copolymers with Young's modulus about 1400 MPa, tensile strength at break higher than 53 MPa, and elongation at break higher than 46%. [ABSTRACT FROM AUTHOR]

Highlights • The reverse disproportionation process is proofed in transesterification system. • An existing conclusion about a constant rate of reverse disproportionation was break. • An more accurate information about the thermodynamic and kinetic was offered. • The available Sn-based intermediate is demonstrated to play a real catalytic role. Abstract The extensive researches about the thermodynamic and intrinsic kinetic of disproportionation reaction of methyl phenyl carbonate to diphenyl carbonate were investigated independently with dibutyltin oxide as a catalyst, at a temperature range of 433.15–473.15 K and different catalyst concentrations in a stirred batch reactor, for a deeper knowledge of reaction essence. This reaction was found endothermic and showed hardly any reaction in the absence of catalyst which indicate an inferior kinetic characteristics. The reaction rate increases with an increasing catalyst concentration until the concentration went to 8.08 × 10−4 mol mol−1. A possible mechanism involving an in-situ Sn-based species was proposed and finally verified by a good agreement between experimental and simulated data. The available Sn-based species was then demonstrated to play a real catalytic role by extra experiments. All results can also be further utilized to explore the essence of transesterification reaction network. [ABSTRACT FROM AUTHOR]

Glycol dicarbonate is successfully synthesized via transesterification of glycol with dimethyl carbonate. A catalyst screening is performed by studying the effect of acidity and alkalinity on the catalytic performance. The results indicate that compared with acidic catalysts, high conversions and yields are obtained with basic catalysts. Ca(OH)2, with medium-strength alkalinity, exhibits excellent catalytic activity with glycol dicarbonate yields of 95%-99% when using a fractionation reaction system. [ABSTRACT FROM AUTHOR]

[Display omitted] • Zirconia crystals influence catalytic behavior of Pb-based catalysts. • TZ-Pb shows higher dispersion degree, larger surface area and more Lewis acid sites. • TZ-Pb is highly active and recyclable for MPC disproportionation. • Tetragonal zirconia is more suitable and stable crystalline phase compared to the monoclinic one. • This work provides prospective reference for extensive utility of zirconia polymorphs in various catalytic applications. Zirconia supported Pb-based catalysts with purely tetragonal/monoclinic crystals were prepared and analyzed well by XRD, TEM-EDS, XPS, H 2 -TPR, BET, Py-IR and NH 3 -TPD techniques. The results indicate that zirconia polymorph has great effect on their structure and catalytic property for the synthesis of diphenyl carbonate (DPC) through methyl phenyl carbonate (MPC) disproportionation due to the differences of surface chemical properties, and tetragonal zirconia supported lead catalyst (TZ-Pb) shows bigger dispersion degree of PbO, higher surface area and Lewis acid amounts and thereby exhibits higher catalytic activity and selectivity compared to monoclinic zirconia supported catalyst (MZ-Pb). Furthermore, TZ-Pb shows better reusability due to strong metal-support interaction and may be readily recycled for at least four times without remarkable reactivity loss. This work provides a prospective reference for the facile and efficient synthesis of zirconia polymorph materials in various catalysis applications. [ABSTRACT FROM AUTHOR]

8-Hydroxyquinoline with Ni(OAc) 2 ·4H 2 O form stable chelate ring structure has good catalytic performance for catalyzing acetylene carbonylation to acrylic acid. [Display omitted] • It was the first time to report the Ni(OAc) 2 ·4H 2 O-8-hydroxyquinoline with high activity for carbonylation of acetylene to acrylic acid. • The catalytic system has no copper, no halogen, no need for acidic protons and no carbon deposition occurring during the reaction process. • The nitrogen-oxygen bidentate ligand with nickel form a ring structure has good catalytic performance in the reaction. • The reaction mechanism catalyzed by Ni(OAc) 2 ·4H 2 O-8-hydroxyquinoline was deduced. A nickel-base nitrogen-oxygen bidentate ligand catalyst was prepared in-situ via the complexation method. Our results show that the ligand with nickel can form a chelate catalyst possessing a ring structure, which exhibits good catalytic performance in the carbonylation reaction of acetylene to acrylic acid (AA). Furthermore, we discovered that, under our optimized conditions, when 8-hydroxyquinoline (HQ) is used as the ligand [c(Ni(OAc) 2 ·4H 2 O) = 15 × 10−6 mol L−1, n(HQ):n(Ni(OAc) 2 ·4H 2 O) = 1:1, V(H 2 O) = 7 mL], 70.1% conversion of acetylene and 92.4% the selectivity of AA is achieved at 200 °C with 8.0 MPa pressure for 30 min. Compared to traditional acetylene carbonylation catalysts and nickel-base phosphine ligand homogeneous complex catalysts, our catalytic system has unique advantages, including no copper, no halogen and no carbon deposition generated during the reaction process. It displays high selectivity and no corrosion of equipment, suggesting that this catalytic system possesses future industrial applications. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Mesoporous carbon-based acid with high -PhSO 3 H density was used for sorbitol dehydration. • Isosorbide yield of 82.7% was obtained under relatively mild conditions. • High catalytic ability was attributed to the structural and acidic properties of catalyst. • Catalyst was reusable up to the fifth cycle without serious deactivation. Abstract Isosorbide, a renewable platform molecule from biomass-derived sorbitol cyclodehydration has attracted much attention over the years. The high yield production of isosorbide from sorbitol by an efficient heterogeneous catalyst under mild conditions is still a tough challenge. Herein, a mesoporous carbon-based acid MC-PhSO 3 H was prepared without assistant of additional templates via grafting benzenesulfonic acid groups to carbonized calcium citrate, and used as a recyclable catalyst to catalyze the dehydration of sorbitol to isosorbide under the solvent-free condition. The MC-PhSO 3 H exhibited highly efficient catalytic ability in isosorbide production with the yield of 82.7% at relatively mild reaction temperature of 160 °C within 1.5 h, which was superior to that of homogeneous H 2 SO 4 and typical strong solid acid SO 4 2−/ZrO 2. The various characterization techniques such as N 2 adsorption-desorption, NH 3 -TPD, pyridine-infrared spectroscopy and sulfur elemental analysis revealed that the good catalytic performance of MC-PhSO 3 H was determined by its mesoporous structure with large surface area and pore volume, suitable hydrophilicity/hydrophobicity character, as well as high density of strong Brønsted acid sites. More importantly, MC-PhSO 3 H could be readily recovered and reused for five consecutive cycles. [ABSTRACT FROM AUTHOR]

Abstract Pb-Zr mixed oxides with 15.2 wt% PbO loading were prepared by four different preparation processes, and their catalytic performances for the disproportionation of methyl phenyl carbonate (MPC) to synthesize diphenyl carbonate (DPC) were evaluated. Physicochemical characterizations including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray fluorescence spectroscopy (XRF), BET surface area measurement, H 2 -temperature programmed reduction (H 2 -TPR), ammonia temperature programmed desorption (NH 3 -TPD) and infrared spectroscopy of pyridine adsorption (Py-IR), as well as catalytic tests of MPC disproportionation reaction showed that catalyst preparation process exerted significant influence on the composition, structural property, catalytic performance of obtained catalysts, and the catalyst prepared by co-precipitation method (PbZr-CP) demonstrated better dispersion of active phase, larger specific surface area and more Lewis acid sites on the surface due to the strong interaction of Pb and Zr, and thus exhibited higher catalytic activity than those prepared by other processes. Graphical abstract Image 1 Highlights • Preparation process exerts significant influence on structural property and catalytic performance of Pb-Zr mixed oxide. • Pb-Zr mixed oxide prepared by co-precipitation is more active. • Well-dispersed PbO and large specific surface area are formed on Pb-Zr catalyst prepared by co-precipitation. • This work provides an effective technology for Pb-Zr catalyst preparation to transform MPC into DPC. [ABSTRACT FROM AUTHOR]

By-products (phenyl salicylate, phenyl 4-hydroxybenzoate, and xanthone) from transesterification between phenol and dimethyl carbonate (DMC) were qualitatively analyzed by gas chromatography-mass spectrometry, and a gas chromatographic method with directed injection for simultaneous quantitative analysis of the product (DPC) and by-products of the transesterification has been established. Based on the results of qualitative and quantitative analyses, the mechanism of the by-products generation was preliminarily deduced. The sample for quantitative analysis was directly diluted in acetone, and related compounds were separated on an HP-5 capillary column and detected by a hydrogen flame ionization detector (FID). The product and by-products were well separated, the correlation coefficients (r) within the concentration range of 1.0 μg/mL–100 μg/mL were ≥0.9997, the relative standard deviations were between 0.5% and 4.4%, spiked recoveries were between 91.5% and 105.6%, and detection limits were between 0.11 and 0.18 μg/mL. The established method is simple, rapid, accurate, sensitive, and highly specific. It is suitable for simultaneous qualitative and quantitative analyses of the product and by-products of transesterification between phenol and DMC. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Bio-based poly(ethylene 2,5-furandicarboxylate- co -ε-caprolactone)s (PEFCLs) were prepared via copolymerization. • PEFCL40 had a Young's modulus 1182 ± 80 MPa, a tensile strength 51 ± 3 MPa and an elongation as high as 981 ± 117%. • The modified materials maintained good thermal stability. Abstract A new bio-based copolyesters, poly(ethylene 2,5-furandicarboxylate- co -ε-caprolactone) (PEFCL), were synthesized from 2,5-furandicarboxylic acid, ethylene glycol and ε-caprolactone. The obtained copolyesters were characterized in terms of chemical structures, thermal and mechanical properties. The characterization results of 1H NMR and 13C NMR had confirmed the insertion of lactones units in PEF chains, all PEFCL copolyesters showed random microstructures. These bio-based copolymers were amorphous and had one glass transition temperature decreased as increasing the CL content. The thermal stability of PEFCL is slightly lower than PEF. Tensile testing revealed that introduction of ε-caprolactone into PEF chains impart PEFCL with excellent mechanical performance, typically, PEFCL40 had a Young's modulus 1182 ± 80 MPa, a tensile strength 51 ± 3 MPa and an elongation as high as 981 ± 117%. [ABSTRACT FROM AUTHOR]

Mesoporous aluminum-promoted sulfated zirconia (named as mAl-SZ) was directly prepared by grind method, and firstly used to catalyze the solvent-free dehydration of sorbitol to isosorbide. The physicochemical properties of as-prepared catalysts were characterized by FT-IR, TGA, XRD, N 2 sorption, NH 3 -TPD and pyridine-infrared (IR) spectroscopy techniques in order to elucidate the relevance of the catalyst properties and the catalytic performance. It was found that the catalysts prepared by grind method possessed mesoporous structures with high surface area, pure tetragonal phase as well as high sulfur contents, which were advantage to eliminate diffusion limitation and generate abundant acidic sites, especially Brönsted acidic sites. Furthermore, aluminum promoters could contribute to the considerable increase of the strong acidic sites and ratio of Brönsted to Lewis acidic sites. Consequently, the mesoporous sulfated zirconia with 6 mol% Al-promoter (6Al-SZ) attained porous structure with improved acidic properties, thus showing the optimal catalytic behavior. The full sorbitol conversion with 73% isosorbide selectivity was achieved under milder conditions (175 °C, 2 h) than those of similar type of catalysts. In addition, the 6Al-SZ exhibited favorable reusability with insignificant drop in isosorbide yield during five reaction cycles. [ABSTRACT FROM AUTHOR]

TiO-RGO composites were prepared and used as efficient heterogeneous catalysts for the transesterification of dimethyl carbonate with phenol. Transmission electron microscopy images demonstrated that the RGO could remarkablely improve the dispersion of TiO. X-ray photoelectron spectroscopy showed that RGO could change the chemical states of Ti species. Py-IR and Py-TPD results indicated the addition of RGO led to the increase of medium Lewis acid sites of TiO, which are positive for the transesterification reaction. The TiO-RGO composite with 50 wt% RGO exhibited a remarkable catalytic performance for the transesterification of dimethyl carbonate with phenol to diphenyl carbonate. Under the optimized conditions, the 53.5% phenol conversion and 99.9% transesterification selectivity were achieved. This phonel conversion of 53.5% could be compared with the result of homogeneous catalysts. RGO has been an excellent structural and electronic promoter in TiO-RGO composites. [ABSTRACT FROM AUTHOR]

Aliphatic-aromatic poly(carbonate- co -ester) random copolymers poly(butylene carbonate- co -furandicarboxylate)s (PBCFs) with different composition had been prepared from dimethyl carbonate (DMC), 1,4-butanediol (BD) and bio-based dimethyl furan-2,5-dicarboxylate (DMFA) by two-step melt polycondensation method. A series of characterization results can be explained as follows: the varying melting temperature ( T m ) and enthalpy ( ΔH m ) displayed that the copolymers were strongly dependent upon the compositions of butylene carbonate (BC) and butylene furandicarboxylate (BF) units. In addition, glass transition temperature ( T g ) noticeably increased with the content of BF units increasing, which agreed with Fox equation; a comparative kinetics research of isothermal crystallization of homopolymer and copolymers with different composition displayed that the existence of BF units could accelerate the crystallization rate of PBC. Furthermore, all of PBCFs exhibited a typical isodimorphic cocrystallization behavior, whose crystal lattice structure shifted from PBC type crystal to PBF type; the thermal stability of PBCFs also expressed to be enhanced during the process of the increasing BF unit content; last but not the least, the mechanical performances could be easily by adjusting the feed components. [ABSTRACT FROM AUTHOR]

Base-free conversion of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) was carried out by a simple and green process based on a novel ionic liquid (IL)-promoted non-noble metal catalytic reaction system. Among various of ILs, 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) was found to be the best IL without addition of base as it has stronger hydrogen bonds formation ability and good thermal stability, as well as free to form definite aggregates. In addition, a series of non-noble metal catalysts containing Ce, Fe, Zr were synthesized and the Ce 0.5 Fe 0.15 Zr 0.35 O 2 catalyst was found to have excellent activity due to the existence of active iron and zirconium species and the formation of CeO 2 -based solid solution, which could create more oxygen vacancies and improve the redox properties of catalyst. Under the optimal reaction condition, almost complete HMF conversion and 44.2% FDCA yield were obtained after 24 h at 160 °C over Ce 0.5 Fe 0.15 Zr 0.35 O 2 in [Bmim]Cl. More importantly, the catalyst could be reused without significant decrease of its catalytic activity. This research not only develops a more environmentally friendly catalytic system that promotes the base-free oxidation of HMF into FDCA, but also provides an economic route to produce FDCA. [ABSTRACT FROM AUTHOR]

Aiming to improve thermal stability of poly(butylene carbonate) (PBC), a series of poly(butylene-co-1,4-cyclohexanedimethylene carbonate) (PBCCs) random copolycarbonates with weight-average molecular weights ( M w ) ranging from 1,09,000 to 1,74,000 g mol −1 and yield of 82.4to 88.4% were synthesized from Diphenyl carbonate (DPC), 1,4-butanediol (BD) and trans-1,4-cyclohexanedimethanol (CHDM) by a two-step melt polycondensation method. The structures and properties were characterized by 1 H NMR, 13 C NMR, FT-IR, GPC, WAXD, DSC, TGA, mechanical testing as well as enzymatic degradation. The results manifested that the triad components were existed in the copolymers with a random sequential structure, and incorporation of cyclohexanedimethylene carbonate (CC) units into PBC could prominently impact the thermal transition behavior, crystallinity as well as thermal stability of PBCCs in a degree. In addition, T g of PBCCs monotonously increased with the increasing CHDM content. WAXD results indicated that the CHDM introduction could obviously change the crystal structure and crystallinity of the copolymers. The thermal stability of PBCCs also expressed to be enhanced during the process of increasing CC unit content. Furthermore, the mechanical properties and biodegradability of copolymers can be easily adjusted by regulating the feed composition. [ABSTRACT FROM AUTHOR]

The C 60 -stabilized Ni catalyst, denoted as Ni/C 60 , was prepared by regular impregnation following the chemical reduction and employed to catalyze hydrogenation of nitrobenzene. The characterizations suggested that reductants, NaBH 4 amount and nickel precursor influenced metallic Ni concentration on surface of catalyst, and C 60 improved the dispersion of Ni and reduced the electron density of metallic Ni. The nitrobenzene conversion and the aniline selectivity both reached above 99.9% over Ni/C 60 , within 40 min under 90 °C and 2 MPa of H 2 . C 60 improved the aniline selectivity and enhanced the stability of Ni/C 60 ascribed to its hydrophobicity. [ABSTRACT FROM AUTHOR]

An environmentally friendly heterogeneous catalyst, Ti-Zn double oxide, was prepared using a sol-gel method and firstly used for the synthesis of diphenyl carbonate (DPC) via the transesterification of phenol and dimethyl carbonate. The catalyst exhibited excellent catalytic activity. Moreover, the effects of Ti to Zn molar ratio, calcination temperature and catalyst amount on the catalytic performances of Ti-Zn double oxide have been investigated. The characterization results of XRD, TGA-DSC, ICP-AES and NH-TPD showed that amorphous TiO was the active sites, and amorphous ZnO was the promoter. Also the amount of Zn remarkably affected the acid amounts of the catalysts, and the calcination temperature not only influenced the acid amount, but also affected the acid strength. Besides, the weak surface acid sites were responsible for the synthesis of MPC and DPC, whereas the strong acid sites favored the formation of a by-product, anisole. The phenol conversion and the transesterification selectivity reached 41.2 and 98.2% over 0.3 g 5TiZn-250 for 8 h, respectively. Furthermore, the prepared catalyst could be reused for three runs without drastic decrease in activity. The slight decreased activity was attributed to the phase change of Ti-Zn double oxide and the leaching of Ti. [ABSTRACT FROM AUTHOR]