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We present the use of the redox active MIL‐100(Fe) metal‐organic framework (MOF) as a catalyst for the oxidation of 5‐hydroxymethyl furfural (HMF) into 2,5‐furan dicarboxylic acid (FDCA) in water. The MOF is synthesised in water alone under mild hydrothermal conditions and 1H NMR is used to analyse the products of HMF oxidation. The MOF in combination with the co‐catalyst TEMPO provides a total selectivity of desired products of 74 % with a maximum FDCA yield of 57 % seen after 24 hours at only 70 °C. The catalyst is recycled ten times with no loss in activity and no evidence of a reduction in the crystallinity of the MOF. [ABSTRACT FROM AUTHOR]

A radiofrequency heated micro-trickle bed reactor with two adjacent thermal zones was designed. In the first thermal zone, citronellal is converted to isopulegol over a H-ZSM-5 catalyst at 80 °C. This is followed by the second thermal zone where hydrogenation isopulegol to menthol occurs over a Pd/TiO 2 catalyst at 70 °C. The two catalytic zones are separated by heating zones made of nickel ferrite particles that produce heat under radiofrequency field at 180 kHz. The position of the catalytic zones was determined based on a one dimensional heat transfer model, in which the actual flow pattern was approximated. Such configuration allows achieving desired temperatures in the catalyst beds whereas the inlet and outlet gas temperatures are close to ambient temperature which increases energy efficiency of the system. The overall product yield was increased by 9 times as compared with a single thermal zone configuration. [ABSTRACT FROM AUTHOR]

Highlights: [•] The conductive losses contribute up to 30% of the total thermal losses from the reactor. [•] At least three heating zones are required to obtain an isothermal length of 50mm with a temperature non-uniformity of 2°C. [•] RF heating is able to uniformly raise the initial temperature of the entire packed bed from 20 to 80°C in 8s. [•] The liquid hold-up of 0.88–0.92 was observed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Dual synergy between Au and Cr-hydrotalcite in liquid-phase alcohol oxidation. [•] Facile O2 activation by a Cr3+ ↔Cr6+ redox cycle at the gold-support interface. [•] Electron transfer from Cr-hydrotalcite to Au during Cr oxidation. [•] α-C–H bond cleavage controls the rate to greater extent than O–H bond cleavage. [•] Increasing Cr content and decreasing Au particle size enhance Au–Cr synergy. [Copyright &y& Elsevier]

Artificial carbon dioxide capture is an alternative method to remove the carbon dioxide already accumulated in the atmosphere as well as to stop its release at its large-scale emission points at the source, such as at power plants. However, new adsorbents are needed to make the approach feasible. For this purpose, in this study, hierarchical mesoporous-microporous chabazite-type zeolites were synthesised by applying a dual-templating method. The microporous zeolite structure-directing agent N,N,N-trimethyl-1-adamantanammonium hydroxide was combined with an organosilane mesopore-generating template, 3-(trimethoxysilyl)propyl octadecyl dimethyl ammonium chloride. Materials were characterised for their structural and textural properties and tested for their carbon dioxide capture capacity both in their original sodium form and in their proton-exchanged form by means of breakthrough curve analysis and sorption isotherms. The influence of template ratios on their structure, carbon dioxide capture, and capacity have been identified. All mesoporous materials showed fast adsorption-desorption kinetics due to a reduction in the steric limitations via the introduction of a meso range network of pores. The hierarchical zeolites are recyclable with a negligible loss in crystallinity and carbon dioxide capture capacity, which makes them potential materials for larger-scale application. [ABSTRACT FROM AUTHOR]

Abstract: Hierarchical SSZ-13 zeolites were synthesized by combining N,N,N-trimethyl-1-adamantanammonium hydroxide (TMAdOH) as the structure-directing agent for chabazite formation with mono- and diquaternary ammonium-type and organosilane mesoporogens and extensively characterized for their structural, textural, and catalytic properties. Mesoporous SSZ-13 zeolites can be synthesized in one step by combining TMAdOH and the diquaternary ammonium-type surfactant C22-4-4Br2. The mesopore volume increases with the mesoporogen/SDA ratio. The hierarchical zeolites are highly crystalline and exhibit similar Brønsted acidity as SSZ-13. Hierarchical SSZ-13 zeolites display increased lifetime in packed-bed MTO experiments than conventional SSZ-13 at similar light olefins yield. The increased lifetime is due to better utilization of the micropore space. With increasing mesoporosity, the micropore space is used more efficiently, but also the rate of coke formation at the crystal periphery increases. Accordingly, the most stable zeolite is obtained at a relatively low C22-4-4Br2/SDA ratio. These zeolite catalysts can be regenerated without substantial loss of activity. [Copyright &y& Elsevier]

A complementary computational and experimental study of the reactivity of Lewis acidic CrCl2, CuCl2 and FeCl2 catalysts towards glucose activation in dialkylimidazolium chloride ionic liquids is performed. The selective dehydration of glucose to 5-hydroxymethylfurfural (HMF) proceeds through the intermediate formation of fructose. Although chromium(II) and copper(II) chlorides are able to dehydrate fructose with high HMF selectivity, reasonable HMF yields from glucose are only obtained with CrCl2 as the catalyst. Glucose conversion by CuCl2 is not selective, while FeCl2 catalyst does not activate sugar molecules. These differences in reactivity are rationalized on the basis of in situ X-ray absorption spectroscopy measurements and the results of density functional theory calculations. The reactivity in glucose dehydration and HMF selectivity are determined by the behavior of the ionic liquid-mediated Lewis acid catalysts towards the initial activation of the sugar molecules. The formation of a coordination complex between the Lewis acidic Cr2+ center and glucose directs glucose transformation into fructose. For Cu2+ the direct coordination of sugar to the copper(II) chloride complex is unfavorable. Glucose deprotonation by a mobile Cl− ligand in the CuCl42− complex initiates the nonselective conversion. In the course of the reaction the Cu2+ ions are reduced to Cu+. Both paths are prohibited for the FeCl2 catalyst. [ABSTRACT FROM AUTHOR]

Stabilization of the CrCl active phase in a thin layer of an ionic liquid covalently grafted to mesoporous silica results in a highly selective catalyst for the dehydration of glucose to 5-hydroxymethylfurfural (HMF) in an aqueous medium. Glucose dehydration in water by using the CrCl-Im-SBA-15 catalyst leads to a 50 % HMF selectivity that can be further increased to up to 70 % by modifying the solvent system. [ABSTRACT FROM AUTHOR]

Zirconia modified SBA-15 becomes a very active catalyst for the selective hydrolysis of cellobiose to glucose after sulfation. Spectroscopic investigations indicate the presence of Brønsted acid sites with similar properties to those present in conventional sulfated zirconia. Indications are found that the sulfate groups attached to zirconia interact with silanol groups of SBA-15. The catalytic activity in cellobiose hydrolysis correlates well with results for temperature-programmed decomposition of i-propylamine for a range of sulfated ZrO/SBA-15 catalysts. A glucose yield of 60% during cellobiose hydrolysis at a reaction time of 90 min at 160 °C is obtained. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: Methane activation via bromination can be a feasible route with selective synthesis of mono-bromomethane. It is known that the condensation of brominated products into higher hydrocarbons can result in coking and deactivation in the presence of di-bromomethane. In this study, selective production of methyl bromide was investigated over sulfated ZrO2 included SBA-15 structures. It was observed that the higher the ZrO2 amounts the higher the conversion, while the catalyst remained >99% selective for the monobrominated methane. Over 25mol.% ZrO2 included SBA-15 catalyst with a BET surface area of 246m2/g, methane was brominated with 69% conversion at 340°C and only CH3Br was selectively produced. [Copyright &y& Elsevier]

Single oxides of Ti and Zr incorporated SBA-15 were prepared and characterized by N2 adsorption, NMR, and XPS techniques. 29Si MAS NMR results suggest the formation of Si–O–X linkages (X: Ti or Zr) by an increase in the ratio of Q 3/ Q 4 in the presence of Ti or Zr. XPS analysis of Ti–SBA-15 catalysts indicate the presence of Ti–O–Si bonds in addition to Ti–O–Ti and Si–O–Si bonds, supporting the NMR evidence. [ABSTRACT FROM AUTHOR]

In order to prepare high surface area highly acidic catalysts, different weight loadings of ZrO2 were incorporated in the SBA-15 structures which are subsequently sulfated by treating in 0.25 M H2SO4. The catalysts were characterized by means of TEM, XRD, N2 adsorption, and 1H MAS NMR. Brønsted type acidities of sulfated zirconia included SBA-15 materials were identified by a sharp 1H MAS NMR line at 10.6 ppm. The highest acidity was obtained in the 25 mol% ZrO2 included SBA-15 catalyst with a BET surface area of 246 m2/g. [ABSTRACT FROM AUTHOR]

Glioblastomas (GBM) are the most frequent brain tumors lacking efficient treatment. The increasingly elucidated gene targets make siRNA-based gene therapy a promising anticancer approach, while an efficient delivery system is urgently needed. Here, polyethyleneimine (PEI)-coated Fe3O4 nanoparticles (NPs) have been developed and applied for siRNA delivery into GBM cells to silence repressor element 1-silencing transcription factor (REST). The prepared PEI-coated Fe3O4 NPs were characterized as magnetic nanoparticles with a positive charge, by transmission electronic microscopy, dynamic light-scattering analysis and a magnetometer. By gel retardation assay, the nanoparticles were found to form complexes with siRNA and the interaction proportion of NP to siRNA was 2.8:1. The cellular uptake of NP/siRNA complexes was verified by prussian blue staining, fluorescence labeling and flow cytometry in U-87 and U-251 GBM cells. Furthermore, the REST silencing examined by realtime polymerase chain reaction (PCR) and Western blotting presented significant reduction of REST in transcription and translation levels. Upon the treatment of NP/siRNA targeting REST, the GBM cell viabilities were inhibited and the migration capacities were repressed remarkably, analyzed by cell counting kit-8 and transwell assay separately. In this study, we demonstrated the PEI-coated Fe3O4 nanoparticle as a vehicle for therapeutic siRNA delivery, at an appropriate NP/siRNA weight ratio for REST silencing in GBM cells, inhibiting cell proliferation and migration efficiently. These might represent a novel potential treatment strategy for GBM. [ABSTRACT FROM AUTHOR]

The optimisation of the crystallisation of the hydrothermally-stable metal–organic framework Yb6-MOF (Yb6(BDC)7(OH)4(H2O)4) to provide a reproducible one-step synthesis is achieved by use of the sodium salt of benzene-1,4-dicarboxylate (Na2BDC) as ligand precursor and control of pH with aqueous NaOH at 190 °C over 3 days. Phase purity is confirmed using powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA). During exploration of synthesis conditions from the same set of chemical reagents, three further ytterbium benzene-1,4-dicarboxylates have been isolated and structurally characterised using single-crystal X-ray diffraction, with phase purity assessed by PXRD and TGA. UOW-3 (Yb2(H2O)6(BDC)3) crystallises by lowering pH, and has a relatively dense three-dimensionally connected structure with no Yb–O–Yb linkages but dimers of Yb bridged by BDC linkers lying in the ab plane with a pseudo, pillared-layered structure, where BDC connects along c. UOW-4 (Yb4(BDC)6(H2O)6) forms under the same chemical conditions but upon lowering the temperature to 100 °C, and this material again contains no Yb–O–Yb linkages, but chains of BDC-bridged Yb centres cross-linked to give a dense three-dimensional structure. Upon increasing pH of the synthesis mixture, the material UOW-5 forms, Yb5O(OH)8(BDC)2(HBDC), consisting of dense inorganic layers of ytterbium oxyhydroxide, cross linked by BDC and HBDC pillars. The formulation is supported by infrared spectroscopy, which provides evidence for the HBDC monoanion, and also the presence of a short O–O distance indicative of hydrogen bonding between a carboxylate OH and an oxide anion of the inorganic layer. UOW-3 and UOW-4 both convert to Yb6-MOF upon heating in water above their synthesis temperature, whereas UOW-5 is hydrothermally stable at 240 °C. The structures of the new materials are discussed in terms of ligand binding modes, and connectivity of metal centres, with comparison to other reported Yb-BDC phases in order to relate structural chemistry to their synthesis conditions and the hydrothermal stability of the materials. [ABSTRACT FROM AUTHOR]

The cover page of the journal "ChemCatChem" is presented.

The volumetric properties of 81 different ionic liquids (ILs) have been modeled as a function of temperature and pressure using an extended version of the group contribution method previously reported by our group (Jacquemin et al. J. Chem. Eng. Data 2008, 53, 716-726). Prior to correlating collected data from the literature using this model, the mathematical gnostics was used to critically analyze experimental density data sets as a function of temperature (from 217-473 K) and pressure (from 0.1-207 MPa) to be then able to recommend one data set for each IL. In addition, recommended density data sets were then fitted as a function of temperature and pressure using a series of mathematical equations reported in the literature. These fitting equations were then assessed through the comparison of the calculated mechanical coefficients with the limited directly measured experimental data reported in the literature. Among these recommended data sets, 5399 density data points for 54 different ILs were then used as the training data set to determine the temperature and pressure dependences on the effective molar volume of 31 different cations and 24 different anions. Then 2522 density data points for 27 other ILs were used as a test data set to determine the accuracy of this method. In light of this analysis, excellent agreement was observed between calculated and recommended literature data within the whole temperature and pressure ranges investigated herein as stated by the overall relative average absolute deviation (RAAD) for each volumetric property, which was lower than 0.31% and 3.5% in the case of the density and isobaric thermal expansion coefficient of pure ILs, respectively. Finally, this model was further assessed with other methods reported in the literature in the case of the evaluation of the density of binary mixtures of two ILs as a function of temperature at atmospheric pressure. This analysis demonstrates that the proposed method shows a good ability to evaluate the density even in the case of mixture of ILs with a RAAD lower than 0.25%. [ABSTRACT FROM AUTHOR]

The viscosity of ionic liquids (ILs) has been modeled as a function of temperature and at atmospheric pressure using a new method based on the UNIFAC-VISCO method. This model extends the calculations previously reported by our group (see Zhao et al. J. Chem. Eng. Data 2016, 61, 2160-2169) which used 154 experimental viscosity data points of 25 ionic liquids for regression of a set of binary interaction parameters and ion Vogel-Fulcher-Tammann (VFT) parameters. Discrepancies in the experimental data of the same IL affect the quality of the correlation and thus the development of the predictive method. In this work, mathematical gnostics was used to analyze the experimental data from different sources and recommend one set of reliable data for each IL. These recommended data (totally 819 data points) for 70 ILs were correlated using this model to obtain an extended set of binary interaction parameters and ion VFT parameters, with a regression accuracy of 1.4%. In addition, 966 experimental viscosity data points for 11 binary mixtures of ILs were collected from literature to establish this model. All the binary data consist of 128 training data points used for the optimization of binary interaction parameters and 838 test data points used for the comparison of the pure evaluated values. The relative average absolute deviation (RAAD) for training and test is 2.9% and 3.9%, respectively. [ABSTRACT FROM AUTHOR]

Glucose conversion to 5-hydroxymethylfurfural (HMF) is important to the success of a biorefinery. Herein, metal–organic frameworks (MOFs) with the UiO-66 structure were synthesised with decanoic acid as the modulator and used as the catalyst to optimise HMF yield. PXRD, FTIR, and TGA/DSC techniques were applied to characterise the materials. The analysis results show that the materials assembled from the ligand 2-nitroterephthalic acid and hexameric Zr-oxo clusters contain decanoic acid chemically bound in the framework that influences porosity, Lewis acidity, and hydrophobicity. The materials exhibit excellent catalytic performance for HMF production from glucose in DMSO as solvent, attributed to their abundant defects and high hydrophobicity due to the addition of the decanoic acid modulator. Influences of catalyst dosages, reaction duration, and temperature were comprehensively investigated, leading to 98.1% conversion of glucose and 54.5% HMF yield under optimised reaction conditions. The catalytic conversion shows some deterioration after four cycles, yet the reaction selectivity displays no significant decline. [ABSTRACT FROM AUTHOR]

Composite NiFe 2 O 4 –TiO 2 magnetic catalysts were prepared by mechanochemical synthesis from a mixture of titania supported nickel ferrite nanoparticles and P25 titania (Evonic). The former provides fast and efficient heating under radiofrequency field, while the latter serves as an active catalyst or catalyst support. The highest heating rate was observed over a catalyst prepared for a milling time of 30 min. The catalytic activity was measured over the sulfated composite catalysts in the condensation of aniline and 3-phenylbutyric acid in a stirred tank reactor and in a continuous RF heated flow reactor in the 140–170 °C range. The product yield of 47% was obtained over the sulfated P25 titania catalyst in the flow reactor. [ABSTRACT FROM AUTHOR]

Highlights: [•] Acidity nanolayered ZSM-5 investigated and tested in methanol-to-hydrocarbons reaction. [•] High number of silanol groups and external Brønsted acid sites. [•] Total methanol turnover trends inversely with Brønsted acid sites concentration. [•] Rate of coke deposition mainly controlled by concentration of Brønsted acid sites. [•] Unilamellar ZSM-5: deviant and more stable performance in methanol conversion. [ABSTRACT FROM AUTHOR]

Abstract: A series of nanostructured Ni–Zn ferrites Ni1−x Zn x Fe2O4 (x=0, 0.5 and 1) with a grain size from 24 to 65nm have been prepared with a sol–gel method. The effect of composition and sintering temperature on morphology, magnetic properties, Curie temperature, specific heating rate at 295kHz and hysteresis loss have been studied. The highest coercivity of 50 and 40Oe, were obtained for NiFe2O4 and Ni0.5Zn0.5Fe2O4 samples with the grain size of 35 and 29nm, respectively. The coercivity of Ni and Ni–Zn mixed ferrites decreased with temperature. The Bloch exponent was 1.5 for all samples. As the grain size increased, the Curie temperature of NiFe2O4 increased from 849 to 859K. The highest saturation magnetization of 70emu/g at 298K and the highest specific heating rate of 1.6K/s under radiofrequency heating at 295kHz were observed over NiFe2O4 calcined at 1073K. Both the magnitude of the hysteresis loss and the temperature dependence of the loss are influenced by the sintering temperature and composition. [Copyright &y& Elsevier]

AWRK6 was a synthesized peptide developed based on the natural occurring peptide dybowskin-2CDYa, which was discovered in frog skin in our previous study. Here, a quantitative determination method for AWRK6 analysis in rat plasma by using liquid chromatography-tandem mass spectrometry (LC-MS/MS) was established and validated following U.S. FDA guidelines. A combination of plasma precipitation and liquid–liquid extraction was applied for the extraction. For pharmacokinetics study, the rats were administrated with AWRK6 via intraperitoneal and intravenous injection. The prepared plasma samples were separated on an ODS column and analyzed by tandem MS using precursor-to-product ion pairs of m/z: 533.4→84.2 for AWRK6 and m/z: 401.9→101.1 for internal standard Polymyxin B sulfate in multiple reaction monitoring mode. AWRK6 concentrations in rat plasma peaked at about 1.2 h after intraperitoneal injections at 2.35, 4.7 and 9.4 mg/kg bodyweight. The terminal half-life was around 2.8 h. The absolute bioavailability of AWRK6 was 50% after 3 doses via injection, and the apparent volume of distribution was 4.884 ± 1.736 L. The obtained determination method and pharmacokinetics profiles of AWRK6 provides a basis for further development, and forms a benchmark reference for peptide quantification. [ABSTRACT FROM AUTHOR]

Abstract: The crystallization of hierarchical ZSM-5 in the presence of the organosilane octadecyl-dimethyl-(3-trimethoxysilyl-propyl)-ammonium chloride as the mesoporogen was investigated as a function of time and temperature. The synthesis by this method proceeds in two steps. The rapid formation of a predominantly amorphous disordered mesoporous aluminosilicate precursor phase is followed by the formation of globular highly mesoporous zeolite particles involving dissolution of the precursor phase. It is difficult to completely convert the initial phase into the final hierarchical zeolite. This limits the amount of aluminium built into the MFI network and the resulting Brønsted acidity. In the presence of iron, more crystalline hierarchical zeolite is obtained. These Fe-containing zeolites are excellent catalysts for the selective oxidation of benzene to phenol. Their hierarchical pore structure leads to higher reaction rates due to increased mass transfer and increased catalyst longevity despite more substantial coke formation. [Copyright &y& Elsevier]

Lignocellulosic biomass, a cheap and plentiful resource, could play a key role in the production of sustainable chemicals. The simple sugars contained in the renewable lignocellulosic biomass can be converted into commercially valuable products such as 5-hydroxymethyl furfural (HMF). A platform molecule, HMF can be transformed into numerous chemical products with potential applications in a wide variety of industries. Of the hexoses contained in the lignocellulosic biomass, the successful production of HMF from glucose has been a challenge. Various heterogeneous catalysts have been proposed over the last decade, ranging from zeolites to metal organic frameworks. The reaction conditions vary in the reports in the literature, which makes it difficult to compare catalysts reported in different studies. In addition, the slight variations in the synthesis of the same material in different laboratories may affect the activity results, because the selectivity towards desired products in this transformation strongly depends on the nature of the active sites. This poses another difficulty for the comparison of different reports. Furthermore, over the last decade the new catalytic systems proposed have increased profoundly. In this article, we summarize the heterogeneous catalysts: Metal Organic Frameworks (MOFs), zeolites and conventional supported catalysts, that have been reported in the recent literature and provide an overview of the observed catalytic activity, in order to provide a comparison. [ABSTRACT FROM AUTHOR]

Metal organic framework UiO‐66 is studied as an adaptable heterogeneous catalyst for glucose conversion. UiO‐66 was modified by; i) partial linker substitution, ii) particle size modulation and iii) linker defects. We studied the effect of crystallinity and functional groups on the glucose conversion and product yields. The main products are: i) fructose from the isomerisation of glucose, ii) mannose from the epimerisation of glucose and iii) 5‐hydroxymethyl furfural from the dehydration of fructose. We found that defective and nano crystalline UiO‐66 catalyst performs best for isomerisation. When 50 % of the linkers of UiO‐66 are replaced by a sulfonate‐containing linker, the catalyst shows higher isomerisation activity than other UiO‐66 catalysts. Naphthalene‐dicarboxylate linkers were introduced to induce hydrophobicity and this catalyst further increased isomerisation activity showing 31 % fructose selectivity. Finally, the promising catalysts were tested in a flow reactor and a bifunctional mixed linker catalyst possessing both hydrophobic and acidic functional groups is shown to be stable in a time‐on‐stream study. [ABSTRACT FROM AUTHOR]

A mechanism of CO oxidation by a thin surface oxide of Rh supported on ceria is proposed: CO is oxidized by the Rh-oxide film, which is subsequently reoxidized by a ceria surface O atom. The proposed mechanism is supported by in situ Raman spectroscopic investigations. [ABSTRACT FROM AUTHOR]

Yb6(BDC)7(OH)4(H2O)4 contains both bridging hydroxyls and metal-coordinated waters, possessing Brønsted and Lewis acid sites. The material crystallises from water at 200 °C. Using the solid as a heterogenous catalyst, glucose is converted into 5-hydroxymethylfurfural, via fructose, with a total selectivity of ∼70% after 24 hours at 140 °C in water alone: the material is recyclable with no loss of crystallinity. [ABSTRACT FROM AUTHOR]

Abstract: Heterogeneous catalysts are desired for the conversion of glucose, the most abundant sugar in renewable biomass, but presently their synthesis requires highly toxic chemicals with long synthesis times. We report the conversion of glucose into fructose and 5‐hydroxymethylfurfural on a heterogeneous catalyst that is stable and selective and operates in the most environmentally benign solvent, water. We used a bifunctional solid with Lewis and Brønsted acid sites by partially replacing the organic linker of the zirconium organic framework UiO‐66 with 2‐monosulfo‐benzene‐1,4‐dicarboxylate. This catalyst showed high product selectivity (90 %) to 5‐hydroxymethylfurfural and fructose at 140 °C in water after a reaction time of 3 h. It was recyclable and showed only a minor loss in activity after the third recycle, offering a realistic solution for the bottleneck glucose isomerization reaction for scale‐up and industrial application of biomass utilization. [ABSTRACT FROM AUTHOR]

Utilisation of lignocellulosic agricultural waste biomass could provide a carbon net zero alternative for production of valuable chemicals. However, the progress is hindered because there's no catalyst to carry out a selective and efficient conversion process. In this study a new promising catalyst for this challenging conversion is reported. It is prepared by sulfonation of activated carbon followed by the impregnation of tin (Sn). The catalyst has been characterized by NH 3 -TPD, FTIR, XRF and N 2 physisorption. The catalyst was tested at 120 °C for the conversion of model carbohydrate mixtures prepared in the laboratory and real biomass mixtures of apple fruit biomass waste. The catalytic performance for the conversion of a model carbohydrate mixture resulted in a 5-hydroxymethylfurfural (5-HMF) yield of 30% in 80 min. On the other hand, catalytic testing of real apple pomace biomass showed a 5-HMF yield of 24% in 80 min. The Sn catalyst was also shown to maintain the 5-HMF yield in recycle experiments using a model carbohydrate mixture. Conversely, stability was lower when the Sn catalyst was tested in real apple pomace mixture, which is likely due to the presence of other impurities. • Low temperature (120 °C) conversion of carbohydrates rich agricultural apple fruit waste to 5-HMF. • Cheap and easy method for the preparation of tin doped sulfonated carbon catalysts. • Characterization revealed that the Sn-Fn-Ac catalyst contained both Lewis and Brønsted acidity. • Sn-Fn-AC showed for glucose, fructose and sucrose mixtures 30% 5-HMF yield at conversion of 60%. • Catalytic conversion of carbohydrate mixtures from biomass yielded 24% of 5-HMF respectively. [ABSTRACT FROM AUTHOR]

The effect of periodic changes in particle velocity on mass transfer to the reacting surface of a magnetic particle with a diameter 225 μm in laminar flow has been investigated in a microfluidic reactor. The periodic particle motion in a fluid was investigated under a sinusoidal magnetic field generated by a quadrupole arrangement of electromagnets around the reactor. The effect of operating frequency of the rotating magnetic field, intensity of the magnetic field, and phase shift between the two sets of magnets on particle dynamics has been studied. Three particle motion modes have been observed depending on the frequency of the applied field. The mass transfer rate was estimated under steady velocity and variable velocity of the particle using a mass transfer correlation by Feng and Michaelides (2001). The validity of this correlation for the case of variable particle velocity has been confirmed with a 2D numerical model, describing actual hydrodynamics and mass transfer towards the particle surface. The mass transfer coefficient depends both on the mean particle velocity and the deviation of velocity from the mean value. The periodic movement with variable particle velocity reduces the mass transfer coefficient by 7.6% as compared to steady state motion with the same mean velocity. [ABSTRACT FROM AUTHOR]

A modified UNIFAC-VISCO group contribution method was developed for the correlation and prediction of viscosity of ionic liquids as a function of temperature at 0.1 MPa. In this original approach, cations and anions were regarded as peculiar molecular groups. The significance of this approach comes from the ability to calculate the viscosity of mixtures of ionic liquids as well as pure ionic liquids. Binary interaction parameters for selected cations and anions were determined by fitting the experimental viscosity data available in literature for selected ionic liquids. The temperature dependence on the viscosity of the cations and anions were fitted to a Vogel-Fulcher-Tamman behavior. Binary interaction parameters and VFT type fitting parameters were then used to determine the viscosity of pure and mixtures of ionic liquids with different combinations of cations and anions to ensure the validity of the prediction method. Consequently, the viscosities of binary ionic liquid mixtures were then calculated by using this prediction method. In this work, the viscosity data of pure ionic liquids and of binary mixtures of ionic liquids are successfully calculated from 293.15 K to 363.15 K at 0.1 MPa. All calculated viscosity data showed excellent agreement with experimental data with a relative absolute average deviation lower than 1.7%. [ABSTRACT FROM AUTHOR]

In this study, we use zeolite Y as a support for the synthesis of Sn and Ga doped zeolites aimed at the isomerization of glucose to fructose. Though these materials are inactive in water, they are active in methanol and we could ascertain a reaction pathway involving a hydride shift for the interconversion of glucose to fructose and mannose, and a Brønsted acid pathway with the formation of a methyl fructoside intermediate and its hydrolysis to fructose if water was added afterwards. By using characterizations comprising: chemisorption, XPS, XRD, HAADF-STEM and EXAFS; it was possible to demonstrate that a straightforward impregnation protocol for the preparation of our catalysts, led to Sn/Y mainly consisting of small SnO 2 clusters on the external surface of the zeolite, whereas Ga/Y consisting of highly dispersed Ga species mostly inside the zeolite pores; and a catalytic activity that appears to be dominated by Brønsted acid sites. [Display omitted] • Ga and Sn-doped zeolites Y are active for the isomerization of glucose to fructose. • The isomerization reaction occurs with sugars interconverting each other. • The catalysts are active in methanol via a methyl fructoside intermediate. • The same catalyst's preparation leads to SnO 2 clusters and Ga dispersed species. • Lewis and Brønsted acid pathways are both operating but dominated by Brønsted. [ABSTRACT FROM AUTHOR]

• Effect of rapid devolatilization on carbonaceous materials investigated for the HIsarna alternative ironmaking process. • Chars produced under high temperature and rapid heating via drop tube furnace (DTF) • Explained the reactivity behaviour of chars from different carbon sources produced under rapid heating. • Revealed the effect of temperature on the physical structure for coal and biomass materials. • To measure the real-time structural changes via high temperature confocal scanning laser microscope (HT- CSLM) To evaluate the potential of using renewable biomass in the novel HIsarna technology, reactivity of thermal coal (TC), charcoal (CC), Bana grass char (BGC) before and after rapid devolatilization at 1500 °C in a drop tube furnace (DTF) was investigated. Thermogravimetric (TG) was used for CO 2 gasification study, and high temperature confocal scanning laser microscope (HT-CSLM), Brunauer-Emmett-Teller (BET) and scanning electron microscopy (SEM) were used to characterise the morphology of all three raw carbonaceous materials and their chars produced by rapid devolatilization. CC has fastest gasification reaction before and after rapid heat treatment, and BGC raw is more reactive than TC raw but BGC 1500 °C and TC 1500 °C have very similar gasification behaviour. The reactivity index of the rapidly devolatilized char is reduced to 84.21% (BGC), 92.11% (TC) and 94.23% (CC) compared to their raw materials. This shows that BGC is more severely affected by the rapid devolatilization, and this behaviour is likely to be governed by the high ash content which will melt and cause pore blockage during heat treatment. According to HT-CSLM results the average particle sizes decreased by 28%, 24% and 20 % for TC, CC and BGC respectively. While the SEM images shown that TC has gone through significant structural changes during the rapid devolatilization, but CC and BGC maintained their parent structural shapes. The BET results indicate that TC is non-porous, but both CC and BGC contain a large number of constricted micropores with significantly larger surface area. [ABSTRACT FROM AUTHOR]

HIsarna ironmaking process is one of the emerging technologies being developed to mitigate the increasing carbon footprint from the steel making industry. This innovative process offers flexibility with the type of reductants used in the smelting reduction vessel for the conversion of iron ore to liquid hot metal. Natural gas is well known for being a relatively clean fossil fuel producing carbon black and hydrogen when it undergoes thermal decomposition. The gasification reactivity of carbon black compared to the carbonaceous materials used in HIsarna process is investigated in this work using isothermal gravimetric analysis (TGA) method at 1250 °C, 1350˚C and 1450 °C under atmospheric pressure. Furthermore, physical-chemical characteristics of the individual carbonaceous materials, which may influence the reactivity, are evaluated systematically. The experimental results show that carbon black is the least reactive followed by thermal coal and charcoal. It was found that the effect of the morphology of the carbonaceous materials on the reactivity is dominant compared to the surface area of the materials. In addition, the reactivity increases with the alkali index (AI) and the level of the amorphousness of the material's structure. Three well-known kinetic models, i.e. the volumetric model (VM), the grain model (GM) and the random pore model (RPM) were applied to predict the gasification behaviour of the three carbonaceous materials. The random pore model best describes the gasification reaction of the selected samples due to the influence of the pore diffusion on the reaction. It is observed that the activation energy of the samples are not following the order of reactivity, this can be explained by the kinetic compensation effect. [ABSTRACT FROM AUTHOR]

The inclusion of ethylene methyl acrylate copolymer (EMA) during the melt mixing of composites of poly(ethylene terephthalate) (PET) and graphene nanoplatelets (GNP) results in increased melt viscosity and shear stresses acting on the molten composite. This is due to ester groups of the acrylates in the co-monomer unit of EMA reacting via transesterification with PET creating cross-linked structures, as confirmed by solid state 13C magic-angle-spinning, nuclear magnetic resonance spectroscopy (13C MAS NMR), Fourier transform infrared (FTIR) spectroscopy and, isothermal time sweep oscillatory rheology measurements. The increase in shear stresses assists the exfoliation of the GNP in the PET matrix, resulting in lower electrical and percolation threshold values. The electrical percolation decreased from a volume fraction of 0.017 to 0.005 GNP and an AC conductivity of the PET-GNP composite on inclusion of EMA as high as 10 S/m attained. The rheological percolation threshold value halved from a volume fraction of ~0.0237 to ~0.0117. Both EMA and GNP had a nucleating effect on the PET, as the crystallization temperature (T c) of PET increased by > 20 °C and the crystalline content (X c) by >25%. Image 1 • EMA reacts with PET to assist exfoliation of graphene during extrusion. • EMA and PET form cross-linked structures. • Cross-linked structures increase melt viscosity and shear stresses during mixing. • Few-layer graphene (GNP) highly dispersed and distributed in the PET matrix. • Very low electrical and rheological percolation threshold values attained. [ABSTRACT FROM AUTHOR]

• Gallium and Tin can be doped in zeolite Y framework successfully. • Ga has similar activity to Sn in the reaction of glucose conversion to HMF. • Ga zeolite Y catalyst can be recycled and regenerated in DMSO. • Ga-Y zeolite gives fructose yield of 5% at 17 % glucose conversion and Sn-Y zeolite gives 17 % yield at 36 % conversion. This study demonstrates the use of gallium and tin modified Y zeolites as catalysts for the conversion of glucose into fructose, mannose and 5-Hydroxymethyl furfural. These catalysts can be synthesised via a simple and scalable procedure that uses commercially available Y zeolite. The catalysts were characterised by various techniques including elemental analysis, electron microscopy, nitrogen physisorption, X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy, solid state nuclear magnetic resonance spectroscopy and X-ray absorption near edge spectroscopy. It is found that tin containing Y zeolite generate a glucose conversion of 36 % and total product yield of 17 % in water. Meanwhile, gallium containing Y zeolite shows an HMF yield of 33 % when reactions were conducted in DMSO. The recyclability of tin and gallium containing Y zeolites were studied in DMSO and the activities of both materials were shown to remain stable. Furthermore, the spent catalysts can be regenerated via calcination in air. [ABSTRACT FROM AUTHOR]

• Cheap catalyst for the conversion of sugars to 5-HMF at 120 °C. • Facile preparation via SnCl 2 exchange to acidic Amberlyst-15 resin. • Catalysts show high stability in continuous flow 5-HMF production. This report discusses the easy and cheap preparation of SnCl 2 exchanged Brønsted acidic Amberlyst-15 ion exchange resin prepared by ion exchange of an aqueous SnCl 2 solution at room temperature. The prepared materials were tested in the conversion of sugars, being glucose, fructose and saccharose to 5-HMF at low temperature conditions (120 °C) and high sugar concentrations (30 wt. %). Materials showed activity in the conversion of glucose, fructose and saccharose. The effect of the repeating exchange procedures on the catalytic performance was studied under batch and continuous flow conditions. The physicochemical properties of the Amberlyst materials were characterized by various techniques, among them NH 3 -TPD, N 2 physisorption and XRF experiments. The superior stability over 120 h and the selectivity towards 5-HMF of the SnCl 2 exchanged Amberlyst material under continuous flow conditions was partially attributed to a reduced concentration of the total acid site concentration, preventing products to react further towards poorly defined humin-type products. [ABSTRACT FROM AUTHOR]

Herein, Zeolitic imidazolate framework-8 (ZIF-8) is considered as an easy and cheap to prepare alternative catalyst for the isomerization of glucose and production of 5-hydroxymethyl furfural (HMF). For the synthesis of the ZIF-8 catalysts two preparation methods were evaluated, being room temperature and hydrothermal synthesis at 140 °C. Of these, the hydrothermal synthesis method yields a material with exceptionally high surface area (1967 m2·g−1). As a catalyst, the ZIF-8 materials generated excellent fructose yields. Specifically, ZIF-8 prepared by hydrothermal synthesis yielded a fructose selectivity of 65% with a glucose conversion of 24% at 100 °C in aqueous reaction medium. However, this selectivity dropped dramatically when the reactions were repeated at higher temperatures (~140 °C). Interestingly, greater quantities of mannose were produced at higher temperatures too. The lack of strong Brønsted acidity in both ZIF-8 materials resulted in poor HMF yields. In order to improve HMF yields, reactions were performed at a lower pH of 1.0. At 140 °C the lower pH was found to drive the reaction towards HMF and double its yield. Despite the excellent performance of ZIF-8 catalysts in batch reactions, their activity did not translate well to the flow reactor over a continuous run of 8 h, which was operating with a residence time of 6 min. The activity of ZIF-8 halved in the flow reactor at 100 °C in ~3 h, which implies that the catalyst's stability was not maintained in the long run. [ABSTRACT FROM AUTHOR]

The metal–organic framework MIL-101(Cr) is known as a solid–acid catalyst for the solution conversion of biomass-derived glucose to 5-hydroxymethyl furfural (5-HMF). We study the substitution of Cr3+ by Fe3+ and Sc3+ in the MIL-101 structure in order to prepare more environmentally benign catalysts. MIL-101(Fe) can be prepared, and the inclusion of Sc is possible at low levels (10% of Fe replaced). On extended synthesis times the polymorphic MIL-88B structure instead forms.Increasing the amount of Sc also only yields MIL-88B, even at short crystallisation times. The MIL-88B structure is unstable under hydrothermal conditions, but in dimethylsulfoxide solvent, it provides 5-HMF from glucose as the major product. The optimum material is a bimetallic (Fe,Sc) form of MIL-88B, which provides ~70% conversion of glucose with 35% selectivity towards 5-HMF after 3 hours at 140 °C: this offers high conversion compared to other heterogeneous catalysts reported in the same solvent. [ABSTRACT FROM AUTHOR]