Search

Zinc-modified alumina catalysts for methyl chloride synthesis were prepared with varying zinc loadings: from 2.4 to 21.1 wt%. The influence of the zinc loading, zinc precursor and the pH of the impregnation on the physico-chemical properties of the catalyst, and on the catalyst activity and selectivity for methyl chloride (MeCl) synthesis was investigated. The prepared catalysts were thoroughly characterized by FTIR, TEM, physisorption and EDX. On the alumina surface, both molecular and bulk zinc species are created upon zinc loading. The surface area of the catalyst decreases steadily with zinc loading. Bulk zinc species dominate on the catalyst starting at a zinc loading of 9.4 wt% and the amount of Lewis acid sites (LAS) decreases. A shift in the acid site type takes place upon zinc modification. Sites assigned to stronger LAS are eliminated while zinc-based weaker acid sites started to predominate. The shift in acidity increases the selectivity and activity of methyl chloride synthesis, which was demonstrated in a series of experiments in a laboratory-scale fixed bed reactor. [ABSTRACT FROM AUTHOR]

Correlative light and electron microscopy (CLEM) is revolutionizing how cell samples are studied. CLEM provides a combination of the molecular and ultrastructural information about a cell. For the execution of CLEM experiments, multimodal fiducial landmarks are applied to precisely overlay light and electron microscopy images. Currently applied fiducials such as quantum dots and organic dye-labeled nanoparticles can be irreversibly quenched by electron beam exposure during electron microscopy. Generally, the sample is therefore investigated with a light microscope first and later with an electron microscope. A versatile fiducial landmark should offer to switch back from electron microscopy to light microscopy while preserving its fluorescent properties. Here, we evaluated green fluorescent and electron dense nanodiamonds for the execution of CLEM experiments and precisely correlated light microscopy and electron microscopy images. We demonstrated that green color emitting fluorescent nanodiamonds withstand electron beam exposure, harsh chemical treatments, heavy metal straining, and, importantly, their fluorescent properties remained intact for light microscopy. [ABSTRACT FROM AUTHOR]

The three-dimensional (3D) structure of the ductal epithelium and the surrounding extracellular matrix (ECM) are integral aspects of the breast tissue, and they have important roles during mammary gland development, function and malignancy. However, the architecture of the branched mammary epithelial network is poorly recapitulated in the current in vitro models. 3D bioprinting is an emerging approach to improve tissue-mimicry in cell culture. Here, we developed and optimized a protocol for 3D bioprinting of normal and cancerous mammary epithelial cells into a branched Y-shape to study the role of cell positioning in the regulation of cell proliferation and invasion. Non-cancerous cells formed continuous 3D cell networks with several organotypic features, whereas the ductal carcinoma in situ (DCIS) –like cancer cells exhibited aberrant basal polarization and defective formation of the basement membrane (BM). Quantitative analysis over time demonstrated that both normal and cancerous cells proliferate more at the branch tips compared to the trunk region of the 3D-bioprinted cultures, and particularly at the tip further away from the branch point. The location-specific rate of proliferation was independent of TGFβ signaling but invasion of the DCIS-like breast cancer cells was reduced upon the inhibition of TGFβ. Thus, our data demonstrate that the 3D-bioprinted cells can sense their position in the branched network of cells and proliferate at the tips, thus recapitulating this feature of mammary epithelial branching morphogenesis. In all, our results demonstrate the capacity of the developed 3D bioprinting method for quantitative analysis of the relationships between tissue structure and cell behavior in breast morphogenesis and cancer. [ABSTRACT FROM AUTHOR]

Titanium silicates of MWW structures with different Si/Ti ratios were prepared via hydrothermal synthesis using piperidine as the structure directing agent and boric acid as the crystallization agent. All the syntheses resulted in highly crystalline materials independent of the Si/Ti ratio. The observed morphology showed MWW-like well-defined thin hexagonal platelets. The synthesized Ti-MWW materials exhibited higher surface areas and partial meso-porosity compared to the commercial TS-1 catalyst. The coordination of the Ti-species was investigated by UV–vis- and IR-spectroscopy. The MWW titanium silicates were tested for the catalytic performance in the epoxidation of propylene in a laboratory-scale trickle bed reactor to compare their clear different physico-chemical properties with the commercial TS-1. The synthesized Ti-MWW materials showed significantly higher catalytic activities, up to 3.5 times, using acetonitrile as the solvent and enhanced epoxide selectivities partially up to 100% in methanol unlike TS-1. The effect of the Ti content in the MWW and the calcination conditions were investigated in propylene epoxidation, revealing the beneficial effect of a lower calcination temperature and an increased Ti content on the activity. The catalytic results were correlated with the physico-chemical properties of the synthesized materials. [ABSTRACT FROM AUTHOR]

• Isoeugenol hydrodeoxygenation was studied over Ni-SBA-15 and Ni-SZ-SBA-15 with sulfated ZrO 2. • 75% yield of propylcyclohexane was obtained over a non acidic Ni-SBA-15. • Ni particles in Ni-SBA-15 (size 20 nm) were mainly located outside SBA-15 promoting HDO. • Ni particles in Ni-SZ-SBA-15 were partially inside the SBA-15 structure, leading a very low HDO activity. • The kinetic model was developed for HDO of isoeugenol based on the proposed reaction network. Hydrodeoxygenation (HDO) of isoeugenol has been investigated over Ni-SBA-15 and Ni-SZ-SBA-15 containing sulfated ZrO 2 with Si/Zr molar ratio of 8.4. The catalysts were prepared via incipient wetness method and characterized by N 2 adsorption, AAS, TPR, X-ray diffraction (XRD), thermal gravimetric/differential thermal analyses (TG-DTA), organic elemental analysis, pyridine adsorption-desorption with Fourier-transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The results revealed that 75% yield of propylcyclohexane was obtained over a non acidic Ni-SBA-15 in isoeugenol HDO at 300 °C under 3 MPa H 2 using dodecane as a solvent. Ni-SZ-SBA-15 gave only very low HDO activity, which is explained by location of the acid sites both inside and outside SBA-15, whereas nickel particles were partially located inside the SBA-15 structure. On the other hand Ni particles in Ni-SBA-15 with the size of 20 nm were located outside SBA-15 promoting HDO. The kinetic model was developed for HDO of isoeugenol based on the proposed reaction network, which took into account formation of intermediate products as well as oligomers. The developed kinetic model was capable of describing well the experimental data with the degree of explanation equal to 91%. The activation energy for hydrogenation of propylcyclohexene and for demethoxylation of dihydroeugenol to 4-propylphenol are equal to 92 kJ/mol and 62 kJ/mol, respectively. [ABSTRACT FROM AUTHOR]

Hydrodeoxygenation (HDO) of isoeugenol was carried out at 200 °C and 30 bar of H2 in a batch reactor using a series of bifunctional catalysts consisting of platinum supported on zeolite H-Beta-25 or H-Beta-300 and Bindzil as a binder. The purpose of the matrix was to understand the effect of the binder on the reaction, emulating the components of industrial catalysts and therefore facilitating catalyst scale-up. The effect of the supports acid strength, the location of metal nanoparticles, and their proximity to acid sites was also studied. The catalysts were characterized by N2 physisorption, inductively coupled plasma atomic emission spectrometry, Fourier transform infrared spectroscopy of adsorbed pyridine and scanning and transmission electron microscopy. It was found that platinum supported only on the zeolite was more active compared to platinum located on the binder. High levels of isoeugenol conversion (ca. 100%), propylcyclohexane yield (56%) and the liquid-phase mass balance (68%) were obtained for the catalyst consisting of Pt supported on both zeolite H-Beta-25 and Bindzil. [ABSTRACT FROM AUTHOR]

Citronellal was converted to menthol in a one-pot approach using H-Beta zeolite-based Ni catalyst in a batch reactor at 80 °C, under 20 bar of total pressure. The effects of H-Beta acidity (H-Beta-25 with the molar ratio SiO2/Al2O3 = 25 and H-Beta-300 with SiO2/Al2O3 = 300) and Ni loading (5, 10 and 15 wt %) on the catalytic performance were investigated. Ni was impregnated on H-Beta support using the evaporation-impregnation method. The physico-chemical properties of the catalysts were characterized by XRD, SEM, TEM, ICP-OES, N2 physisorption, TPR, and pyridine adsorption–desorption FTIR techniques. Activity and selectivity of catalysts were strongly affected by the Brønsted and Lewis acid sites concentration and strength, Ni loading, its particle size and dispersion. A synergetic effect of appropriate acidity and suitable Ni loading in 15 wt.% Ni/H-Beta-25 catalyst led to the best performance giving 36% yield of menthols and 77% stereoselectivity to (±)-menthol isomer at 93% citronellal conversion. Moreover, the catalyst was successfully regenerated and reused giving similar activity, selectivity and stereoselectivity to the desired (±)-menthol isomer as the fresh one. [ABSTRACT FROM AUTHOR]

The purpose of this work was to investigate biomass-derived ethanol dehydrogenation into acetaldehyde using several mono- and multicomponent (CuO, ZnO and Cr 2 O 3 )-containing catalysts supported on industrial size Al 2 O 3 beads. The catalysts, prepared with either solution combustion or incipient wetness method, were characterized by using various physico-chemical methods, such as EDXA, SEM-EDXA, TEM, XRD, XPS, pyridine adsorption desorption FTIR, and ζ-potential measurements. The results revealed that the multicomponent catalysts exhibited superior activity compared to the metal oxide catalysts containing only one metal oxide. In addition, the most selective catalyst towards acetaldehyde formation, with 50% selectivity at 55% conversion of ethanol at 300 °C and WHSV 1 h −1 was CuO Cr 2 O 3 /Al 2 O 3 prepared by using the solution combustion method, indicating that this inexpensive and rapid catalyst preparation method is promising for other applications. [ABSTRACT FROM AUTHOR]

As a proof of concept, here it is established that curcumin integrated chitosan oligosaccharide lactate (COL) self-assembles on silica nanoparticle surface to form nano hybrid particles (NHPs). These NHPs have size in the ranges of 25–35 nm with silica nanoparticle as its core and curcumin-COL as outer layer having thickness of 4–8 nm. The fluorescence intensity of these NHPs are found to be quenched and emission maximum is ~50 nm red shifted compared to free curcumin implying inner filter effect and/or homo-FRET between curcumin molecules present on the surface of individual nano hybrid particle. Although fluorescence of free curcumin is remarkably quenched by Hg 2+ /Cu 2+ ions due to chelation through keto-enol form, the fluorescence of NHPs is unaffected by Hg 2+ /Cu 2+ ion that boosts analytical selectivity. The fluorescence intensity is outstandingly enhanced in the presence of cholesterol but is not influenced by ascorbic acid, uric acid, glucose, albumin, lipid and other potential interfering substances that either obstruct during enzymatic reaction or affect fluorescence of free curcumin. Thus, NHPs outstandingly improve analytical specificity, selectivity and sensitivity during cholesterol estimation compared to free curcumin. The interaction between cholesterol and NHPs is found to be a combination of ground state electrostatic interaction through the free hydroxyl group of cholesterol along with hydrophobic interaction between NHPs and cholesterol and excited state interaction. The proposed cholesterol biosensor illustrates a wider linear dynamic range, 0.002–10 mmol L −1 , (upper limit is due to lack of solubility of cholesterol) needed for biomedical application and better than reported values during enzymatic reaction. In addition, the NHPs are found to be photo-stable potentially making it suitable for simple, quick and cost-effective cholesterol estimation and opening an alternative approach other than enzymatic reaction using nano hybrid structure to tune analytical specificity, selectivity and sensitivity of probe molecule. [ABSTRACT FROM AUTHOR]

[Display omitted] • Co-processing of n-hexadecane with lignin derived isoeugenol. • Mono- and bimetallic iron and nickel supported on H-Y-5.1 zeolite. • Minor quantities of isoeugenol retard hydroisomerization-hydrocracking of hexadecane. Structure sensitivity in HDO. • Hydrogen TPD can serve as a descriptor of hydrodeoxygenation. Co-processing of n-hexadecane with lignin derived isoeugenol as a model compound was investigated in this work using low-cost mono- and bimetallic iron and nickel supported on H-Y-5.1 zeolite. Different Fe-Ni metal ratios in the catalyst led to different reaction rates of processes and product distribution. The presence of just 0.26 wt% isoeugenol in the mixture with n-hexadecane made hydroisomerization-hydrocracking of the latter two-fold less active. Catalysts with smaller metal particle sizes, lower than 6 nm were more efficient pointing out on structure sensitivity. Extremely high activity in co-processing was obtained over 2 wt% Fe – 8 wt% Ni/H-Y-5.1 catalysts with the median metal particle size of 4.6 nm and metals-to-acid site ratio of 8.6. Fe catalyst were much less active in isoeugenol hydrodeoxygenation, while high cracking activity of hexadecane was observed in the presence of Ni. Alkylation of n-hexadecane was a feature of 8 wt% Fe – 2 wt% Ni/H-Y-5.1, whereas, over the 5 wt% Fe – 5 wt% Ni/H-Y-5.1 bifunctional catalyst no undesired oxygen-containing cyclic products were detected. This catalyst exhibited the highest hydrogen consumption according to temperature programmed desorption, which can serve as a marker for efficient hydrodeoxygenation. The spent catalysts contained ca 40 wt% of coke with predominantly aliphatic species. [ABSTRACT FROM AUTHOR]

In this work, the formation of levulinic acid (LA) as one of the top-twelve chemical building blocks from glucose was studied. In particular, the formulations of heterogeneous acid catalysts based on SBA-15, MCM-41 mesoporous silica was carried out and their performance in catalytic conversion of glucose to LA were assessed and compared with commercial H-Beta-25 (SiO2/Al2O3 = 25) microporous zeolite. The high surface area, suitable porosity, balanced acid sites were considered as the main factors of a proper catalytic performance. Thus, essential modification of mesoporous SBA-15 and MCM-41 materials was carried out by introducing Al in their structures for Lewis acid sites improvement. Alumina was introduced to SBA-15 by post synthesis evaporation impregnation method while it was embedded inside the MCM-41 mesoporous material during the synthesis. In addition, Brønsted acidity was introduced via post-synthesis grafting of sulfonic acid groups. The textural and morphological features and acidity of the materials were investigated using N2 physisorption, SEM, EDX, TEM, XRD and pyridine-FTIR. All catalysts were tested for aqueous glucose conversion in an autoclave at 180 °C. Al-MCM-SO3H has shown the best performance with 54% of LA yield after 4 h reaction. According to Py-FTIR introduction of alumina and sulfonic acid groups improved weak and medium Lewis and Brønsted acid sites. However, the Brønsted to Lewis acid site ratio (B/L) was higher for Al-MCM-SO3H compared to SBA-Al-SO3H leading the reaction pathway to LA. H-Beta-25 zeolite displayed a poor performance because of harsh medium and strong acid sites catalyzing humins formation. [ABSTRACT FROM AUTHOR]

The influence of the size and oxidation state of Au nanoparticles (AuNPs) as electrocatalysts for the electro-oxidation of cellulose was studied. Carbon paper electrodes modified with AuNPs were used as the electrocatalysts for the electro-oxidation of cellulose dissolved in 1.3 m NaOH. The size and oxidation state of the AuNPs were determined by using SEM, TEM, and X-ray photoelectron spectroscopy. Both the size and the oxidation state of the AuNPs were found to influence the electrocatalytic properties of the electrode, as studied by using cyclic voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy. The carbon paper electrodes decorated with AuNPs (less than 25 nm) that consist of metallic Au gave rise to a significantly higher electrocatalytic activity than a bare polycrystalline Au electrode. [ABSTRACT FROM AUTHOR]

Plastics are one of the most widely used polymeric materials. However, they are often undegradable and non‐recyclable due to the very stable covalent bonds of macromolecules, causing environmental pollution and health problems. Here, we report that liquid‐liquid phase separation (LLPS) could drive the formation of robust, stable, and sustainable plastics using small molecules. The LLPS process could sequester and concentrate solutes, strengthen the non‐covalent association between molecules and produce a bulk material whose property was highly related to the encapsulated water amounts. It was a robust plastic with a remarkable Young's modulus of 139.5 MPa when the water content was low while became adhesive and could instantly self‐heal with more absorbed water. Finally, responsiveness enabled the material to be highly recyclable. This work allowed us to understand the LLPS at the molecular level and demonstrated that LLPS is a promising approach to exploring eco‐friendly supramolecular plastics that are potential substitutes for conventional polymers. [ABSTRACT FROM AUTHOR]

Plastics are one of the most widely used polymeric materials. However, they are often undegradable and non‐recyclable due to the very stable covalent bonds of macromolecules, causing environmental pollution and health problems. Here, we report that liquid‐liquid phase separation (LLPS) could drive the formation of robust, stable, and sustainable plastics using small molecules. The LLPS process could sequester and concentrate solutes, strengthen the non‐covalent association between molecules and produce a bulk material whose property was highly related to the encapsulated water amounts. It was a robust plastic with a remarkable Young's modulus of 139.5 MPa when the water content was low while became adhesive and could instantly self‐heal with more absorbed water. Finally, responsiveness enabled the material to be highly recyclable. This work allowed us to understand the LLPS at the molecular level and demonstrated that LLPS is a promising approach to exploring eco‐friendly supramolecular plastics that are potential substitutes for conventional polymers. [ABSTRACT FROM AUTHOR]

Viruses play a major role in modern society and create risks from global pandemics and bioterrorism to challenges in agriculture. Virus infectivity assays and genome copy number determination methods are often used to obtain information on virus preparations used in diagnostics and vaccine development. However, these methods do not provide information on virus particle count. Current methods to measure the number of viral particles are often cumbersome and require highly purified virus preparations and expensive instrumentation. To tackle these problems, we developed a simple and cost-effective time-resolved luminescence-based method for virus particle quantification. This mix-and-measure technique is based on the recognition of the virus particles by an external Eu3+-peptide probe, providing results on virus count in minutes. The method enables the detection of non-enveloped and enveloped viruses, having over tenfold higher detectability for enveloped, dynamic range from 5E6 to 3E10 vp/mL, than non-enveloped viruses. Multiple non-enveloped and enveloped viruses were used to demonstrate the functionality and robustness of the Protein-Probe method. [ABSTRACT FROM AUTHOR]

In the present work, the formulation and performance of the silica-aluminosilicate-based composites were studied for catalytic conversion of sugars to levulinic acid. Tailoring the acidity, surface area and the porosity of the catalysts were the main goal of the work. The acidities of the catalysts were provided by ZSM-5 zeolite and were modulated by microwave assisted solid state ion-exchange with copper. The high surface area and porosity of the catalysts were guaranteed by mesopores silica type HMS. The composites of HMS and CuZSM-5 with different contents of 30%, 50%, 60% and 70% were synthesized and the morphological and textural features and acidity of the materials were assessed using XRD, EDX, SEM, TEM, N 2 -physisorption, and FTIR, FTIR with pyridine and NH 3 -TPD. CuZ(60%)@H composite acted as the best catalyst with production of 45% yield and 30% yield of LA from glucose and cellulose conversion, respectively. High surface area, large pore size and volume of HMS in the best composite structure favored mass transfer of the substrates and products and higher performance of the catalyst especially in cellulose hydrolysis. In addition, tuned and balanced concentration, strength and type of CuZSM-5 acidity in the composite promoted the desired pathway, favored formation of levulinic acid and suppressed humins formation. [Display omitted] • Ion-exchanged CuZSM5 with optimum acidity for sugars conversion to levulinic acid. • HMS with high surface area and suitable porosity for facile cellulose mass transfer. • The composite of CuZSM5 and HMS with suitable acidity and porosity. • CuZ(60%)@H composite as a promising catalyst for sugars conversion to levulinic acid. [ABSTRACT FROM AUTHOR]

Formic acid is one of the key components in green chemistry being involved in energy storage, production of chemical intermediates and fuel components. Therefore the knowledge of its stability is of crucial importance and a systematic study of its decomposition is needed. The kinetics of formic acid decomposition to hydrogen and carbon dioxide was investigated in a laboratory-scale fixed bed reactor at 150–225 °C and atmospheric pressure. Palladium nanoparticles deposited on porous active carbon Sibunit were used as the heterogeneous catalyst. The catalyst was characterized by nitrogen physisorption and high-resolution transmission electron microscopy. The average palladium nanoparticle size was 5–6 nm. The impacts of mass transfer resistance and formic acid dimerization were negligible under the reaction conditions. Prolonged experiments revealed that the catalyst had a good stability. Hydrogen and carbon dioxide were the absolutely dominant reaction products, whereas the amounts of carbon monoxide and water were negligible. The experimental data were described with three kinetic models: first order kinetics, two-step adsorption-reaction model and multistep adsorption-decomposition model of formic acid. The multistep model gave the best description of the data. [Display omitted] • Formic acid is very important molecule in large-scale production, biomass conversion and energy storage • Catalytic decomposition of formic acid was studied from kinetic, mass transfer and reactor perspectives • A model for the decomposition process in a fixed bed reactor was developed • The model gave a good description of experimental data [ABSTRACT FROM AUTHOR]

[Display omitted] • Prins cyclisation from isovaleraldehyde and isoprenol to tetrahydropyranol. • Zeolites with varying acidity and hierarchical materials as catalysts. • H-Beta-300 zeolite giving 72% selectivity to the desired product at 99% conversion. • The cis/trans ratio of tetrahydropyranols depends on porous structure. • Parallel formation of tetrahydropyranol and dihydropyran confirmed by DFT. In this work, several heterogeneous micro- and mesoporous, acidic catalysts were tested for the selective synthesis of Florol®, an industrial product formed via condensation and rehydration starting from isoprenol and isovaleraldehyde in dimethylcarbonate as a solvent. The results showed that a mildly acidic, microporous H-Beta-300 with SiO 2 /Al 2 O 3 ratio of 300 was the best catalyst, giving 72% selectivity with 99% conversion at 40 °C when using the molar ratio isoprenol to isovaleraldehyde of 1:5. More acidic zeolites gave slightly lower selectivity, while the lowest selectivity (up to 52%) was obtained with mesoporous catalysts exhibiting mild acidity and no strong Brønsted acid sites. Selectivity to pyranols was nearly constant when changing temperature, while a larger excess of isovaleraldehyde promoted formation of tetrahydropyranol. H-Beta-300 catalyst was successfully after calcination at 400 °C. DFT calculations pointed out on the parallel formation of tetrahydro pyranols and dihydropyrans, which are the corresponding dehydration products. [ABSTRACT FROM AUTHOR]

Several bimetallic Ni Co catalysts supported on θ-Al2O3 together with 10 wt% Ni and 10 wt% Co on θ-Al2O3 were prepared via the incipient wetness method, characterized by X-ray diffraction (XRD), nitrogen adsorption, transmission electron microscopy, temperature programmed reduction, temperature programmed CO2 desorption, Fourier Transformed Infrared Spectroscopy (FTIR) with pyridine adsorption-desorption and tested in dry methane reforming at 700°C in a fixed bed reactor. According to XRD the metal oxide crystallite sizes decreased from 20 nm for 10 wt% Co/θ-Al2O3 to 13 nm for 5 wt% Ni-5 wt% Co/θ-Al2O3, which also showed formation of a mixed oxide alloy. The unit cell parameters for spinel in the fresh catalyst and fcc metal formed during the reaction followed the Vegard’s rule. Although monometallic 10 wt% Co/ θ-Al2O3 exhibited high hydrogen consumption, desorption temperature was also high resulting in a rather low activity of 10 wt% Co/θ-Al2O3 in comparison to bimetallic 5 wt% Ni5 wt% Co/θ-Al2O3. The latter exhibited the highest initial activity for hydrogen formation due to its relatively small metal particle size. This catalyst suffered, however, from extensive coking. The most stable catalyst was 10 wt% Ni/θ-Al2O3 for which the hydrogen yield decreased form 56% to 45% during 100 h time-on-stream. For this s catalyst no sintering occurred, opposite to 10 wt% Co/θ-Al2O3. [ABSTRACT FROM AUTHOR]

Three-dimensional correlative light and electron microscopy (3D CLEM) is attaining popularity as a potential technique to explore the functional aspects of a cell together with high-resolution ultrastructural details across the cell volume. To perform such a 3D CLEM experiment, there is an imperative requirement for multi-modal probes that are both fluorescent and electron-dense. These multi-modal probes will serve as landmarks in matching up the large full cell volume datasets acquired by different imaging modalities. Fluorescent nanodiamonds (FNDs) are a unique nanosized, fluorescent, and electron-dense material from the nanocarbon family. We hereby propose a novel and straightforward method for executing 3D CLEM using FNDs as multi-modal landmarks. We demonstrate that FND is biocompatible and is easily identified both in living cell fluorescence imaging and in serial block-face scanning electron microscopy (SB-EM). We illustrate the method by registering multi-modal datasets. [ABSTRACT FROM AUTHOR]

• A clear impact of the precursor on physico-chemical properties of solution impregnated Ni in zeolite 5A and 13X was shown. • Significant differences were also observed in activity and selectivity of the prepared catalysts in CO 2 methanation. • Besides the choice of precursor, the calcination temperature also influenced clearly the performance of the catalysts. • Detailed catalyst characterization was performed. • 13X was concluded to be the superior support and nickel citrate was the best precursor. Zeolite 13X and 5A supported Ni catalysts were synthesized for CO 2 methanation using the evaporation impregnation method. The influence of using different Ni precursors (nitrate, citrate, and acetate) as well as calcination temperatures on the catalyst properties and performance were investigated. XRD, SEM-EDX, TEM, STEM-EDX, N 2 physisorption, H 2- TPR, TPD-NH 3 and TG/DTA were used for detailed characterization of the catalysts. The parent structure of the zeolites did not change during catalyst synthesis. Using nickel citrate and acetate resulted in smaller NiO particle size compared to nitrate. STEM-EDX results showed that all the Ni-precursor complexes entered more efficiently the 13X zeolite structure, which is mainly due to steric hindrance resulting from the smaller pore size of 5A. Methanation experiments revealed that the 13X catalysts synthesized using nickel citrate (5% Ni) displayed clearly higher activity, compared to the catalysts synthesized using nickel nitrate or nickel acetate. A 79% conversion at 320 °C was obtained with 100% selectivity towards CH 4 and the catalyst showed excellent stability during 200 h testing. Overall, it can be concluded that the Ni precursor significantly influences the physico-chemical characteristics and catalytic properties of Ni 13X and Ni 5A zeolite catalysts in CO 2 methanation: complex size and pore size matter. [ABSTRACT FROM AUTHOR]

Molecular self‐assembly has been widely used to develop nanocarriers for drug delivery. However, most of them have unsatisfactory drug loading capacity (DLC) and the dilemma between stimuli‐responsiveness and stability, stagnating their translational process. Herein, we overcame these drawbacks using dynamic combinatorial chemistry. A carrier molecule was spontaneously and quantitatively synthesized, aided by co‐self‐assembly with a template molecule and an anti‐cancer drug doxorubicin (DOX) from a dynamic combinatorial library that was operated by disulfide exchange under thermodynamic control. The highly selective synthesis guaranteed a stable yet pH‐ and redox‐ responsive nanocarrier with a maximized DLC of 40.1 % and an enhanced drug potency to fight DOX resistance in vitro and in vivo. Our findings suggested that harnessing the interplay between synthesis and self‐assembly in complex chemical systems could yield functional nanomaterials for advanced applications. [ABSTRACT FROM AUTHOR]

Molecular self‐assembly has been widely used to develop nanocarriers for drug delivery. However, most of them have unsatisfactory drug loading capacity (DLC) and the dilemma between stimuli‐responsiveness and stability, stagnating their translational process. Herein, we overcame these drawbacks using dynamic combinatorial chemistry. A carrier molecule was spontaneously and quantitatively synthesized, aided by co‐self‐assembly with a template molecule and an anti‐cancer drug doxorubicin (DOX) from a dynamic combinatorial library that was operated by disulfide exchange under thermodynamic control. The highly selective synthesis guaranteed a stable yet pH‐ and redox‐ responsive nanocarrier with a maximized DLC of 40.1 % and an enhanced drug potency to fight DOX resistance in vitro and in vivo. Our findings suggested that harnessing the interplay between synthesis and self‐assembly in complex chemical systems could yield functional nanomaterials for advanced applications. [ABSTRACT FROM AUTHOR]

Kinetics of guaiacol hydrodeoxygenation (HDO) was studied using supported MoxC–SBA-15 and as a comparison 5 wt% Pt/C under 30 bar hydrogen at 200 °C and 300 °C. Catalyst characterization was done by a range of physical methods including also determination of the amount of coke and the nature of adsorbed species. Pt/C gave 2-methoxycyclohexanol as the main product, whereas Mo2C–SBA-15 promoted direct deoxygenation exhibiting also strong adsorption of guaiacol on the catalyst surface and formation of oligomers. Thermodynamics of guaiacol HDO was elucidated and the reaction network was proposed based on which kinetic modelling was done. [ABSTRACT FROM AUTHOR]

Transition metal nitrides, carbides and phosphides have the potential to replace the expensive and hazardous catalysts typically used for the conversion of fatty acids. However, there has been little research on the influence of treatment conditions and precursor nature on the properties of such catalytic systems. To better understand these dependencies, we synthesized a number of Mo catalysts by temperature‐programmed reduction (700‐900 °C; CH4/N2, N2/H2) using ammonium heptamolybdate, diammonium phosphate and hexamethylenetetramine (HMT) as Mo, C, N and P sources. The presence of HMT in the precursor mixtures ensured the synthesis of pure phase Mo2C, Mo2N and MoP. Catalytic activity in the (hydro)deoxygenation of stearic acid (240 min; 360 °C; 50 bar of H2) decreased in the following order: Mo2C>Mo2N>MoP. However, all of the studied Mo‐based catalysts showed good deoxygenation efficiency and, thus, represent excellent alternatives to traditional noble and sulfur‐containing catalysts. [ABSTRACT FROM AUTHOR]

Kinetics of the cross aldol condensation of valeraldehyde with cyclopentanone was investigated in a batch reactor under atmospheric pressure at 130 °C using heterogeneous metal modified oxides, such as CeO2-MgO, FeO-MgO, FeO-CaO as well as pristine CaO as catalysts. The catalysts were prepared either by evaporation impregnation or deposition precipitation methods and characterized by XRD, TEM, SEM, nitrogen adsorption, ammonia and CO2 TPD. The results revealed that an optimum amount of strong basic sites gives the highest ratio between cross condensation and self-condensation products of valeraldehyde. The highest yield of the desired product 2-pentylidenecyclopentanone (66%) was obtained with FeO-MgO prepared by the deposition precipitation methods.Graphical Abstract: Cross-condensation of valeraldehyde with cyclopentanone was investigated over heterogeneous Fe-CaO, CeO-MgO, FeO-CaO and CaO catalysts at 130 °C using cyclopentanone as a solvent and reactant. The highest yield of the desired product, 2-pentylidene-cyclopentanone, finding applications as fragrances, flavours and pharmaceuticals, was 66% obtained over FeO-MgO catalyst exhibiting both acid and basic sites. [ABSTRACT FROM AUTHOR]

• Ethene oxychlorination over CeO 2 was performed in a microreactor. • CeO 2 catalyst was prepared without any promotors by deposition-precipitation. • The effect of the reactant concentration on the activation energy was revealed. • The previously developed reaction network over ceria was completed. • Kinetic modelling was successfully carried out based on the proposed mechanism. Oxychlorination of ethene was conducted in a microreactor (150–375 °C) over a thin layer of CeO 2 prepared in the current work with the specific surface area of 80 m2/g and compared with the same reaction in millireactors (250–500 °C). The kinetic analysis revealed influence of the ethene concentration on the apparent activation energy which was different in micro- and millireactors. The previously developed reaction network was completed by including two parallel reactions for formation of ethylchloride and vinylchloride and two consecutive reactions accounting for formation of dichloroethane and vinylchloride via ethyl chloride. The reaction orders with respect to HCl and O 2 in the microreactor were comparable with the literature data for millireactors. Kinetic modeling was successfully carried for all reactants by using a steady state model of a packed bed reactor. [ABSTRACT FROM AUTHOR]

Synthesis of materials with combined chemistry and textural properties of carbon and silica aerogels was studied. The synthesized support was modified with ruthenium using evaporation impregnation and deposition-precipitation methods. The ruthenium modification methods were observed to influence the particle size, dispersion, surface area, pore volume and acidity of Ru-C-SiO2 catalysts. Ruthenium particles of 1-2 nm were obtained with a simple impregnation-evaporation method, while deposition precipitations technique gave ruthenium particles ranging from 1 to 8 nm. Small Ru nanoparticles (1-2 nm) were stable even after being exposed at 700 °C or washed with ethanol for regeneration. Furthermore, the catalytic properties of Ru-C-SiO2 catalysts in sugar hydrogenation were also observed to be influenced by the synthesis methods. The catalysts were tested in hydrogenation of sugars with different molecule sizes (i.e. glucose and cellobiose). D-Glucose was more reactive than D-cellobiose when they were studied separately. For the mixture of sugars higher reactivity of both sugars was observed in comparison with neat substrates for the catalyst made by evaporation-impregnation. On the contrary no significant differences between kinetics of the separated sugars and their mixture were observed for the catalyst prepared by deposition-precipitation. The results can be attributed to acidity and a combination of meso and microporosity of the catalysts. The support composite material could also be produced as a monolith, being a promising candidate for future industrial applications.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Oxychlorination of ethene was performed over CuCl 2 /γ-Al 2 O 3 catalyst in a microreactor (460 µm in diameter) and for comparison in a millireactor (1 cm in diameter). A copper-modified catalyst was prepared by a conventional evaporation–impregnation method without any promotors (e.g., K, Na, La) using copper (II) chloride as a precursor. The catalyst was characterized by nitrogen physisorption, Fourier transform infrared spectroscopy using pyridine, temperature-programmed desorption of CO 2 , scanning electron microscopy, energy-dispersive X-ray microanalysis, and transmission electron microscopy. Different reactor types led to notable differences in catalytic performance at the same partial pressures in terms of both activity and selectivity. A higher reaction rate was achieved in the microreactor, which was 4.5 times faster. The activity decline and different selectivity to the desired product are explained by a change in the oxychlorination mechanism due to a different ratio of reagents in the mixture during the reaction. [ABSTRACT FROM AUTHOR]

Hydrodeoxygenation of isoeugenol was investigated at 200 °C under 3 MPa total pressure in dodecane as a solvent, in hydrogen, over bifunctional Pt‐ and Ir‐modified Beta zeolites and mesoporous materials. As a comparison, Pt and Ir supported on Al2O3, SiO2 and mesoporous MCM‐41 were also tested. The catalysts were characterized by XRD, CO pulse chemisorption, transmission electron microscopy, scanning electron microscopy, nitrogen adsorption and FTIR pyridine adsorption desorption. The results revealed that the most active and selective catalyst was Pt‐H‐Beta‐300, which exhibits the lowest acidity and largest crystal size of Beta zeolite among the studied Pt‐ and Ir‐modified Beta zeolites. Complete conversion of isoeugenol and 89 % selectivity to propylcyclohexane was obtained with this catalyst in 240 min. The overall deoxygenation selectivity was 100 %, giving dialkylated cyclohexanes as the second major product. The catalyst was regenerated, reduced and reused in the hydrodeoxygenation of isoeugenol with almost the same performance as the fresh catalyst. Thermodynamic analyses and kinetic modelling of the data were also performed. [ABSTRACT FROM AUTHOR]

Five different support materials were modified with 5 wt.% Cu, using an evaporation impregnation method. The synthesized CuCl 2 /γ-Al 2 O 3 , CuCl 2 /TiO 2 (Hombikat), CuCl 2 /TiO 2 (Alfa Aesar), CuCl 2 /SiO 2 and CuCl 2 /H-Beta-25 materials were characterized by nitrogen physisorption, X-ray powder diffraction, scanning electron microscopy, energy dispersive Xray microanalysis, transmission electron microscopy, Fourier transform infrared spectroscopy and CO 2 -temperature programmed desorption. The physical-chemical characterization was correlated with catalytic activity, stability and selectivity in the ethylene oxychlorination. It was found that γ-Al 2 O 3 and TiO 2 support materials demonstrate very good activity and 1,2dichloroethane selectivity compare to other catalysts. Zeolite H-Beta-25 and SiO 2 support materials proved to be unusable for this reaction. [ABSTRACT FROM AUTHOR]

Abstract: Synthesis of multi-component cobalt based catalysts with different metal precursors and thermal treatment was performed. A special emphasis was put on promotion with ceria. Catalysts, which were synthesized from thermally pre-activated CoCO3·mCo(OH)2·nH2O as a precursor and thereafter underwent reduction in flowing hydrogen, have a clear tendency for decomposition of mixed aluminum–cobalt containing complexes, inevitably formed during thermal treatment. The catalysts were tested in steam reforming of hydrocarbons. The size of metal particles in reduced catalysts was determined by TEM and related to catalytic activity.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Correlative light and electron microscopy (CLEM) allows combining the advantages of fluorescence microscopy and electron microscopy for cell imaging. Rare phenomenon expressing cells can be studied by specifically tagged fluorophores with fluorescence microscopy. Subsequently, cells can be fixed and ultra-structural details can be studied with transmission electron microscopy (TEM) at a higher resolution. However, precise landmarks are necessary to track the same cell throughout the CLEM process. In this technical report, we present a high contrast inkjet-printed gold nanoparticle patterns over commercial glass coverslip to facilitate cell tracking with correlative microscopy. High contrast and strong reflection from nano gold pattern can be used as a fixed landmark for cell identification with fluorescence microscopy. Nano gold printed letters over coverslips are visible in resin blocks, which can be further used to identify the cell of interest for performing sectioning of embedded cell blocks for TEM. [ABSTRACT FROM AUTHOR]

Biofilm formation and dipeptidyl peptidase IV (DPPIV) enzyme activity contribute to the virulence of oral bacteria, and these virulence factors are partly regulated by quorum sensing signaling system. We recently demonstrated that estradiol regulates growth properties and DPPIV activity of Prevotella intermedia , Prevotella nigrescens , and Prevotella pallens . Here, we examined the DPPIV dependency of biofilm formation of Prevotella aurantiaca. Three strains (two clinical strains AHN 37505 and 37552 and the type strain CCUG 57723) were incubated in three estradiol concentrations (30, 90, and 120 nmol/L). Regulation of DPPIV activity, biofilm and fimbria formation, and coaggregation of bacterial strains were analyzed after incubation with four concentrations (10 nM, 100 nM, 1 μM, 10 μM) of dihydroxy-2,3-pentaedione (DPD), the universal precursor of autoinducer -2 (AI-2), and analogs (ethyl-DPD, butyl-DPD, and isobutyl-DPD) for 24 h. Estradiol enhanced the planktonic growth, coaggregation, and biofilm formation of P. aurantiaca strains. The whole cell extract of AHN 37505 had the highest DPPIV activity, followed by CCUG 57723 and AHN 37552. Inhibition of DPPIV activity with di-isopropylfluorophosphate suppressed the effect of estradiol on biofilm formation. At 100 nM and 10 μM concentrations of DPD, butyl DPD, and isobutyl DPD, biofilm formation of P. aurantiaca was significantly inhibited. Fimbriae formation was enhanced up to concentrations of 100 nM and 1 μM followed by a significant inhibition at higher concentrations of DPD and all analogs. A slight but significant inhibitory effect of DPD and analogs on DPPIV activity was observed. Our results indicate that DPPIV plays a key role in the estradiol-regulated biofilm formation of P. aurantiaca. Quorum sensing autoinducer DPD and C1-alkyl analogs could inhibit biofilm-related virulence of P. aurantiaca . [ABSTRACT FROM AUTHOR]

Partial oxidation of ethanol to acetaldehyde was carried out over gold catalysts supported on various oxides and zeolites by deposition precipitation. The special focus of this work was on the influence of H-Y zeolite surface charge on Au cluster size and loading linking it to activity and selectivity in ethanol oxidation and comparing with other studied catalysts. The catalysts were characterized by nitrogen physisorption, transmission electron microscopy (TEM), scanning electron microscopy/energy dispersive X-ray analysis (SEM/EDXA), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and zeta potential measurements. pH of the solution governed the Au NPs size within the range of 5.8–13.2 nm with less negatively charged surfaces leading to formation of smaller clusters. Au loading on H-Y zeolite with silica to alumina ratio of 80 was increased by raising the pH. In fact, H-Y-12 and H-Beta-25 were selective towards diethyl ether while acetaldehyde was the prevalent product on less acidic H-Y-80. The results demonstrated strong dependency of the catalytic activity on the Au cluster size. Namely turn over frequency (TOF) decreased with an increase in metal size from 6.3 to 9.3 nm on H-Y-80. Selectivity towards acetaldehyde and ethyl acetate did not change significantly on H-Y-80 within 6.3–9.3 nm Au particle size range. On Al 2 O 3 support, however, selectivity towards acetaldehyde increased considerably upon diminishing Au average particle size from 3.7 to 2.1 nm. [ABSTRACT FROM AUTHOR]

Stearoyl ethanolamine was synthesized by amidation of stearic acid with ethanolamine in solventless conditions. Iron containing heterogeneous catalysts supported on SiO 2 , Al 2 O 3 , Beta (BEA), ZSM-12 (MTW) and Ferrierite (FER) were used in this work. Sn-modified Ferrierite and H-Ferrierite were also studied for comparison. Fe-modified catalysts synthesized using solid state ion-exchange and evaporation impregnation methods, were thoroughly characterized with X-ray powder diffraction, scanning electron microscope, FTIR with pyridine, nitrogen adsorption, energy dispersive X-ray microanalysis and Mössbauer spectroscopy. The highest conversion was obtained with Fe-H-FER-20 at 140 °C in 1 h giving 61% conversion and 98% selectivity towards the desired amide. The catalytic performance in terms of turnover frequency per mole of iron was achieved with the catalyst exhibiting the largest amount of Fe 3+ species, optimum acidity and a relatively low Brønsted to Lewis acid site ratio. [ABSTRACT FROM AUTHOR]

Kinetics in the hydrodeoxygenation of stearic acid was investigated over Ni-γ-Al 2 O 3 catalyst. The main variables were catalyst prereduction mode, reaction atmosphere and hydrogen pressure in the total pressure range of 7–30 bar. The results revealed that high conversion, 99% in 360 min and high selectivity to heptadecane, 97% were achieved at 300 °C under 30 bar total pressure. The yield of an intermediate hydrogenation product, stearyl alcohol increased with increasing hydrogen pressure as expected. Higher reaction rates and conversion levels were also achieved with the prereduced catalyst and carrying out the reaction in the presence of hydrogen. As a comparison to stearic acid, hydrodeoxygenation of tall oil fatty acids, an industrial feedstock was successfully demonstrated with Ni-γ-Al 2 O 3 under the same conditions. A kinetic model including the pressure effect was derived and applied for data with Ni-γ-Al 2 O 3 as well as for Pd/C, Ni-H-Y-80 and Ni/SiO 2 catalysts. The model described well the kinetic data. [ABSTRACT FROM AUTHOR]

Persistent luminescence (PeL) materials are used in everyday glow-in-the-dark applications and they show high potential for, e.g., medical imaging, night-vision surveillance, and enhancement of solar cells. However, the best performing materials contain rare earths and/or other heavy metal and expensive elements such as Ga and Ge, increasing the production costs. Here, (Li,Na)8Al6Si6O24(Cl,S)2:Ti, a heavy-metal- and rare-earth-free low-cost material is presented. It can give white PeL that stays 7 h above the 0.3 mcd m−2 limit and is observable for more than 100 h with a spectrometer. This is a record-long duration for white PeL and visible PeL without rare earths. The material has great potential to be applied in white light emitting devices (LEDs) combined with self-sustained night vision using only a single phosphor. The material also exhibits PeL in aqueous suspensions and is capable of showing easily detectable photoluminescence even in nanomolar concentrations, indicating potential for use as a diagnostic marker. Because it is excitable with sunlight, this material is expected to additionally be well-suited for outdoor applications. [ABSTRACT FROM AUTHOR]

Sulfur-free Ni supported on H-Y zeolites, γ-Al 2 O 3 and SiO 2 synthesized by the wet impregnation method, and Pd/C were tested in hydrodeoxygenation (HDO) of stearic acid. The catalysts were forming n- heptadecane except Ni/H-Y-80, which was producing n- heptadecane and n- octadecane. Ni/H-Y 80 and Pd/C were tested on HDO of fatty acid methyl esters from chlorella, tall oil fatty acids, and animal fat. The reactions converting the substrates to the final products followed the path from unsaturated esters to acids, with hydrogenation of the latter into alcohols (i.e., stearyl alcohol), and finally formation of hydrocarbons. Ni/H-Y-80 permitted rapid and complete conversion into hydrocarbons, while Pd/C displayed 5–20 times lower turnover frequency, producing saturated intermediates along with hydrocarbons. The catalyst reusability of Ni supported on Y zeolites was studied by recycling and regenerating the spent catalyst from fatty acid HDO. The catalysts demonstrated the possibility of restoring the rates per unit of surface area after regeneration. Catalysts used in HDO of different feedstocks were investigated by thermogravimetric analysis, inductively coupled plasma-optical emission spectroscopy, transmission electron microscopy, surface area measurements, and pore size analysis. [ABSTRACT FROM AUTHOR]

Sn–Al-Beta zeolite was prepared through a hydrothermal method and further modified by alkali and alkaline earth (e.g. Sr and Ba) metals not practically altering the textural properties of the catalyst. The catalytic materials were tested in glucose transformation to methyl lactate in a batch reactor at 180 °C allowing to correlate catalytic activity and selectivity with the strength and type of acid sites. The results showed that by suppressing the Brønsted acidity of the modified catalyst with different promoters the yield of methyl lactate can be increased from ca. 20% to over 50%. Modification of Sn-Beta zeolite by alkali and alkaline earth (e.g. Sr and Ba) metals not practically altering the textural properties of the catalyst was essential for catalytic properties. The yield of methyl lactate can be increased from ca. 20% to over 50% by suppressing the Brønsted acidity of the modified catalyst with different promoters. [Display omitted] • Modification of Sn-Beta zeolite with alkali and alkaline earth (e.g. Sr and Ba) metals. • Glucose transformations to methyl lactate over these catalysts. • Catalytic activity and selectivity correlated with the strength and type of acid sites. • Suppressing Brønsted acidity increased methyl lactate yield from ca. 30% to over 50%. [ABSTRACT FROM AUTHOR]

• Higher activity of smaller gold nanoparticles (AuNPs) towards glucose and xylose hydrogenation and oxidation was observed. • Higher extent of HER observed with xylose solution compared to glucose when moving towards more negative potentials (in-situ FTIR-ATR). Electrocatalytic conversion of hemicellulose-derived glucose and xylose presents a sustainable approach to utilize renewable energy (e.g. solar, wind) to produce value-added chemicals. In this work, the electrochemical hydrogenation and oxidation of glucose and xylose at ambient conditions were studied using dispersed, mesoporous Sibunit Carbon (SC)-supported Au nanocatalysts (SC/AuNPs) with different cluster sizes (4.4 nm, 5.9 nm, 10-30 nm), providing novel results on the cluster size - activity relation. For the electrocatalytic hydrogenation (ECH) of glucose and xylose into sorbitol and xylitol, respectively, higher conversion rates were obtained when more negative potentials were applied. This indicates that the hydrogenation reaction proceeds concurrently with hydrogen evolution reaction (HER). SC/AuNPs with smaller Au clusters were more active towards glucose or xylose ECH at all potentials applied. The selectivity (Faradaic efficiency) increased towards more negative potentials for glucose ECH but followed an opposite trend for xylose ECH. Analysis using in-situ FTIR-ATR spectroscopy showed that water adsorption which leads to HER, was more extensive in xylose solution than in glucose solution at lower potentials. This would indicate greater inhibition of xylose ECH than glucose ECH at more negative potentials. The electrocatalytic oxidation (ECO) of glucose and xylose to gluconic acid and xylonic acid, respectively, was observed to occur at -0.05, +0.3, and +0.4 V (vs Ag/AgCl) using the present electrocatalytic set up. Constant-potential electrolysis at these potentials showed differences in ECO rate depending on the applied potential and average Au cluster size. The highest glucose and xylose ECO rate was obtained for the SC/AuNPs with the smallest average Au cluster size (4.4 nm) at +0.3 V. Constant-potential electrolysis of the sugars at +0.3 V using this catalyst resulted in 42 % yield of gluconic acid and 32 % yield of xylonic acid in 6 hours, both with a very low Au loading of 0.08 % wt.. These results show the strong influence of Au cluster size on the catalytic activities of SC/AuNPs toward sugar ECH or ECO. [Display omitted] [ABSTRACT FROM AUTHOR]

Extraction of lipids from Chlorella algae with supercritical hexane resulted in the high lipids yield of approximately 10% obtained at optimum conditions in terms of extraction time and agitation compared to the total content of lipids being 12%. Furthermore, an easiness of hexane recovery may be considered as economically and ecologically attractive. For the first time, in the current work catalytic hydrodeoxygenation (HDO) of Chlorella algal lipids was studied over 5 wt % Ni/SiO2 at 300 °C and under 30 bar total pressure in H2. The conversion of lipids was about 15% as the catalyst was totally deactivated after 60 min. The transformation of lipids proceeded mostly via hydrogenation and hydrogenolysis with formation of free fatty acid (FFA). Lower activity might be attributed to deactivation of catalysts caused by chlorophylls and carotenoids. Even though the conversion is low, future studies in HDO of lipids extracted from other algae species having higher lipid content could be proposed. A coke resistant catalyst might be considered to improve catalytic activity. [ABSTRACT FROM AUTHOR]

• Microreactor channels were coated with Au/γ-Al 2 O 3 catalyst. • The presence of active gold nanoparticles was confirmed. • Selective oxidation of methanol, ethanol, propanol and butanol was successfully conducted and modelled mathematically. • The role of intrawashcoat diffusion in the catalyst layer was revealed. Selective oxidation of methanol, ethanol, 1-propanol and 1-butanol to corresponding aldehydes was performed in a microreactor in the presence of a Au/γ-Al 2 O 3 coated catalyst. Nanoparticle size distribution, acidity, specific surface area and the average pore size as well as uniformity and thickness of the coating layer were evaluated with relevant characterization techniques. The experiments were designed to reveal the effect of temperature, residence time and oxygen-to-alcohol ratio on both alcohol conversion and product distribution. Stability and repeatability of the coating procedure was successfully demonstrated. To describe the reaction kinetics, plausible kinetic equations were implemented in a pseudo-homogeneous plug flow model, which turned out to be an adequate approximation to describe the flow pattern in the microreactor. Non-linear regression analysis enabled the determination of the rate and adsorption parameters included in the kinetic model. An advanced kinetic and mass transfer model was developed to reveal the impact of the diffusion inside the catalytic washcoat layer, confirming that molecular diffusion is not a limiting factor for alcohol oxidation in the microreactor. [ABSTRACT FROM AUTHOR]

• Different AuNPs size distribution among CF/AuNPs catalysts resulting from different pre-treatment methods of the CF support (chemical and thermal pre-treatment) prior to Au deposition. • Higher reaction rates of glucose and xylose toward ECH over a CF/AuNPs catalyst than polycrystalline Au. • Variation of ECSA-normalized ECH activity and Faradaic Efficiency (FE) of CF/AuNPs catalysts depending on the catalyst Au cluster size. Recent evidences have shown catalyst structure sensitivity of electrocatalytic hydrogenation (ECH) of organic molecules in aqueous phase. In this study, ECH of glucose and xylose was investigated using gold nanoparticles (AuNPs) on activated carbon fiber (CF) support as catalyst. CF supported AuNPs catalysts (CF/AuNPs) were synthesized by deposition-precipitation method and were characterized by physicochemical (SEM, TEM, XRD, N 2 physisorption, ICP-OES) and electrochemical methods. Chemical or thermal pre-treatment of CF prior to Au deposition resulted in different AuNPs size distributions. The activity towards glucose or xylose ECH were observed to be dependent on the particle size of AuNPs and the applied potential. Compared to a polycrystalline Au catalyst, higher reaction rates for glucose and xylose ECH were observed for a CF/AuNPs catalyst with a higher surface area. This indicates that the activity of Au towards glucose and xylose ECH is dependent on the surface area and particle size, and particle size control can be achieved by simple chemical or thermal pretreatment of the catalyst support. [Display omitted] [ABSTRACT FROM AUTHOR]

Catalytic synthesis of a dioxinol compound, (2 S ,4a R ,8 R ,8a R )-4,4,7-trimethyl-2-phenyl-4a,5,8,8a-tetrahydro-4 H -benzo[d][1,3]dioxin-8-ol, exhibiting analgesic activity was demonstrated over Fe-modified beta zeolite. During interactions between cis-verbenol oxide and benzaldehyde, two main reactions occurred. In the first reaction, namely isomerization of verbenol oxide both cyclopentenic hydroxyketone, oxetane as well as a cyclohexyl compound, (1 R ,2 R ,6 S )-3-methyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diol were formed. In the second parallel reaction the target compound was generated. The highest yield of the target compound was achieved in the reaction between verbenol oxide and benzaldehyde at their molar ratio of 1:133 with the bifunctional iron modified Fe-H-Beta-150 catalyst at 70 °C giving a much higher yield than reported earlier in the literature, being 46 mol-% at complete conversion of verbenol oxide. [ABSTRACT FROM AUTHOR]

One-pot continuous synthesis of menthols both from citronellal and citral was investigated over 5 wt% Ni supported on H-Beta-38-sepiolite composite catalyst at 60–70 °C under 10–29 bar hydrogen pressure. A relatively high menthols yield of 53% and 49% and stereoselectivity to menthol of 71–76% and 72–74% were obtained from citronellal and citral respectively at the contact time 4.2 min, 70 °C and 20 bar. Citral conversion noticeably decreased with time-on-stream under 10 and 15 bar of hydrogen pressure accompanied by accumulation of citronellal, the primary hydrogenation product of citral, practically not affecting selectivity to menthol. A substantial amount of defuctionalization products observed during citral conversion, especially at the beginning of the reaction (ca. 1 h), indicated that all intermediates could contribute to formation of menthanes. Ni/H-Beta-38-sepiolite composite material prepared by extrusion was characterized by TEM, SEM, XPS, XRD, ICP-OES, N 2 physisorption and FTIR techniques to perceive the interrelation between the physico-chemical and catalytic properties. [Display omitted] • one-pot continuous synthesis of menthols from citronellal and citral. • 5 wt% Ni supported on H-Beta-38-sepiolite composite catalyst. • menthols yield of 53% and 49% from citronellal and citral. • stereoselectivity to menthol ca. 70–75%. [ABSTRACT FROM AUTHOR]

[Display omitted] • One-pot citral to menthol transformations over bifunctional Ru/H-Y-80 extrudates. • Long-term experiments in a continuous reactor. • Menthol isomers distribution and Z/E-citral ratio were influenced by Ru size. One-pot transformations of citral were investigated over Ru-catalysts in a batch and a continuous mode over a powder catalyst and extrudates, respectively. Ru/H-Y-80 catalysts were prepared by different impregnation methods to obtain different particle sizes of Ru. The highest yield of isopulegols was 15% and yield of menthols was 3% with stereoselectivity to the desired (±)-menthol isomer of 42% after 5 h over the Ru/H-Y-80 powder catalyst with the smallest metal particles prepared by the incipient wetness impregnation method with six impregnation steps using Ru(NO)(NO 3) 3 as a precursor. This catalyst was synthesized with the Bindzil binder and shaped by extrusion. For comparison, also a catalyst with Ru deposited on the binder was prepared. Addition of 30 wt% Bindzil binder to Ru/H-Y-80 catalyst caused significant catalyst deactivation. Z/E-citral ratio decreased with increasing Ru particle size. Citral conversion and the yield of acyclic hydrogenation products were higher over the powder catalysts containing a mixture of zeolite and binder with a larger distance between the metal and the acid sites, i.e. with Ru deposited on the Bindzil binder. Long-term experiments in the continuous mode revealed comparable catalytic behaviour of both Ru-extrudates with the controlled metal location due to the presence of diffusion regime. The maximum yield of menthols, 6%, with stereoselectivity to the desired (±)-menthol of 73% was obtained during the transient state, below 2 h of time-on-stream. The reuse of Ru/H-Y-80 extrudates was successfully demonstrated. [ABSTRACT FROM AUTHOR]

Four clay materials, namely, bentonite, bleaching earth, attapulgite and sepiolite, were shaped into the cylindrical body by extrusion. Clays were characterized in depth by TEM, SEM-EDX, N 2 physisorption, pyridine FTIR, pH measurements, contact angle measurements, 27Al MAS NMR, and the crush test. Catalytic properties were investigated in the citronellal cyclization as a model reaction. The reaction was performed in the trickle-bed reactor at 70 °C, 10 bar of Ar with 0.086 M initial citronellal concentration in cyclohexane. The best results were obtained over attapulgite with isopulegols yield of 24% and stereoselectivity to the desired isopulegol isomer of 61%. Attapulgite had the highest meso-to-micropore volume ratio, the highest basicity, a low Brønsted-to-Lewis acid sites ratio, and the lowest amount of Brønsted acid sites compared to other extrudates. In addition, same clay exhibited the highest mechanical strength of extrudates. [Display omitted] • Extrusion of bentonite, attapulgite and sepiolite and detailed characterization. • citronellal cyclization as a model reaction in trickle-bed at 70 °C. • Over attapulgite selectivity to isopulegols of 92%. • Catalytic behavior linked to the micro-to-mesopore volume ratio, basicity, Brønsted-to-Lewis acid sites ratio. [ABSTRACT FROM AUTHOR]

The present work is focused on the improvement of an effective approach to tailor the acidity of silica alumina composite. SBA-15 was selected based on high surface area, uniform porosity and large mesopores. Modification of SBA-15 was performed to improve both Lewis and Brønsted acidities and hence catalyst activity. Therefore, introduction of alumina as a co-catalyst was carried out to enhance Lewis acid sites through its incorporation into the silica network. Evaporation impregnation method was evaluated for incorporation of aluminium to SBA-15 and materials with different SiO 2 /Al 2 O 3 ratios were prepared. Acidity and morphological features of the materials were assessed using XRD, EDX, SEM, TEM, N 2 -physisorption, 27Al MAS-NMR and FTIR with pyridine. Brønsted acidity was attained by the introduction of sulfonic acid groups in the final catalyst via the post-synthesis grafting method. Therefore, the balanced Lewis and Brønsted acidities and proper porosity of modified SBA-15 led to its efficient performance in the conversion of glucose as a biomass-based model component to levulinic acid. [Display omitted] • Acid sites modification of siliceous-based mesoporous material (SBA-15). • Alumina introduction as Lewis acid sites by evaporation impregnation technique. • Sulfonic acid groups incorporation as Brønsted acid sites by post-grafting method. • Obtaining the balanced acidity for biomass-based glucose transformation to levulinic acid. [ABSTRACT FROM AUTHOR]