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Co–Fe bimetallic nanoparticles-affixed polyvinylidene fluoride-co-hexafluoropropylene (PVdF-HFP) nanofiber membrane is fabricated using the electrospinning and chemical reduction techniques. The semicrystalline polymeric backbone decorated with the highly crystalline Co–Fe bimetallic nanoparticles enunciates the mechanical integrity, while the incessant and swift electron mobility is articulated with the consistent dissemination of bimetallic nanoparticles on the intersected and multi-layered polymeric nanofibers. The diffusion and adsorption of glucose are expedited in the extended cavities and porosities of as-formulated polymeric nanofibers, maximizing the glucose utilization efficacy, while the uniformly implanted Co4+/Fe3+ active centers on PVdF-HFP nanofibers maximize the electrocatalytic activity toward glucose oxidation under alkaline regimes. Thus, the combinative sorts including nanofiber and nanocomposite strategies of PVdF-HFP/Co–Fe membrane assimilate the enzyme-less electrochemical glucose detection concerts of high sensitivity (375.01 μA mM−1 cm−2), low limit of detection (0.65 μm), and wide linear range (0.001 to 8 mM), outfitting the erstwhile enzyme-less glucose detection reports. Additionally, the endowments of high selectivity and real sample glucose-sensing analyses of PVdF-HFP/Co–Fe along with the binder-less and free-standing characteristics construct the state-of-the-art paradigm for the evolution of affordable enzyme-less electrochemical glucose sensors. [ABSTRACT FROM AUTHOR]

Nickel cobalt bimetallic nanoparticles (NiCo NPs) with different molar ratios were stabilized over three-dimensional nitrogen-doped graphene [3D-(N)G] by a chemical coreduction method. Various spectroscopic and microscopic analysis techniques were employed to characterize the resulting NiCo@3D-(N)G samples. The catalytic activity of as-synthesized material was examined for thermal decomposition of ammonium perchlorate (AP) using differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). In presence of NiCo@3D-(N)G nanocomposite, the decomposition temperature was decreased by 140.9 °C and the high-temperature decomposition peak of AP disappeared. Also, the total heat release during decomposition of AP was significantly increased to about 1176.6 J g−1. The presented catalyst exhibits an impressive catalytic effect for thermal decomposition of AP, due to its unique properties including porous structure, good dispersion of NiCo NPs over 3D-(N)G, consolidated interaction between 3D-(N)G and NiCo NPs, and synergistic effect between two metals. [ABSTRACT FROM AUTHOR]

Supported ruthenium nanoparticles were prepared through the chemical reduction of aqueous Ru(III) species previously loaded (1 or 5 wt%) onto DD3 kaolin through an ion-exchanged pathway. Resulting nanoporous materials were characterized by XRF, XRD, TEM, EDX, and N2 sorption measurements, and then used as catalysts in the liquid phase aerobic oxidation of benzyl alcohol. Benzaldehyde was obtained as the main product with a 97% yield at 100% alcohol conversion at 100 °C in the presence of Ru-DD3 (5%) using 10 mL/min O2 flow and 10 mol% of tert-butyl hydroperoxide with respect to the substrate. Oxidation tests were more efficient in the case of Ru-DD3 (5%) than with other Ru-based solids such as Ru-HZSM-5 (5%). It was also shown that, in the presence of Ru-DD3 (5%), the aerobic oxidation of benylalcohol in the presence of an amine (aniline) gives rise to the imine instead of the aldehyde through a one-pot oxidation and condensation process. [ABSTRACT FROM AUTHOR]

The synthesis of (6-ethyl-1,6-dihydropyrrolo[3,2-c]carbazol-2-yl)methanol 5 and (6-ethyl-6,11-dihydro-1H-dipyrrolo[3,2-c:2′,3′-g]carbazole-2,10-diyl)dimethanol 6 were achieved via the reduction of methyl pyrrolo carbazole carboxylate 3 and methyl dipyrrolo carbazole carboxylate 4, respectively. The structures of hydroxymethyl-pyrrolocarbazoles 5 and 6 were supported by FT-IR, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, 1H and 13C NMR spectroscopy. The photophysical properties of the targeted compounds 3-6 were investigated by employing absorption and fluorescence spectroscopy in different common organic solvents. Also, the fluorescence lifetime (τF) of the compounds was measured utilizing a time-correlated single-photon counting technique in tetrahydrofuran. Antioxidant activities of compounds 3-6 were determined by employing three different assays, namely DPPH radical scavenging, ABTS cation radical decolarization and cupric reducing antioxidant capacity. The results revealed that the ABTS cationic scavenging activity assay was found to be the most sensitive method for the determination of inhibition values. [ABSTRACT FROM AUTHOR]

Modified semi-coke catalysts loaded melamine (M) and/or manganese oxides (MnOx) were prepared by the impregnation method for the reduction of NO at low temperature. A fixed-bed reactor, XRD, Raman and XPS were used for the catalytic activity measurement and characterization of modified semi-coke catalysts. The highest denitration rate of 5M-10Mn-ASC was 91.6% at 225 °C and kept the highest level within 200-300 °C. The results of characterization revealed the changes of nitrogen functional groups on the surface of modified semi-coke catalysts. Pyrrolic-like nitrogen (N-5) appeared on the surface of semi-coke catalysts only with M. After loading M and MnOx simultaneously, quaternary nitrogen (N-Q) appeared and the contribution of nitro type complexes (-NO2) declined sharply. During the whole reaction process, melamine as a nitrogen species source can adjust both the contribution of acidic and basic functional groups. The acidic functional groups, like C=O and N-Q, could provide active sites to adsorb NH3 and the basic functional groups, like pyridinic-like nitrogen (N-6) and N-5, could adsorb some O2 and NO. Meanwhile, the sufficient oxygen vacancies and surface chemical oxygen provided by MnOx reinforced denitration efficiency of modified semi-coke catalysts as well. Different modified conditions would result in the changing roles of nitrogen functional groups constantly, which could be beneficial to improve the denitration rate. Based on the results of catalytic activity measurements and analysis of different characterization, the possible denitrification mechanism of modified semi-coke catalysts was built. [ABSTRACT FROM AUTHOR]

Abstract: We synthesized the reproducible heterogeneous catalyst of graphene oxide (GO)-supported palladium nanoparticles (NPs) via a simple and green process. The structure, morphology and physicochemical properties of the synthesized heterogeneous catalyst were characterized by the latest techniques such as high-resolution transmission electron microscopy (TEM), scanning TEM, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, and X-ray photoelectron spectroscopy. The GO-supported Pd NPs (Pd/GO nanocatalyst) exhibited excellent catalytic activity for the reduction of nitroaromatics to aminoaromatics in aqueous sodium borohydride. The nitroaromatics were converted to corresponding aminoaromatics with high yields (up to 99%) using Pd/GO nanocatalyst in aqueous solution. The hybrid heterogeneous catalyst showed 83% of conversion after six cycles in the reduction of nitrobenzene to aminobenzene. These features ensured the high catalytic activity of the introduced graphene oxide supported Pd nanocatalysts.Graphical abstract: [ABSTRACT FROM AUTHOR]

Abstract: In this study, an efficient route for graphene oxide (GO) and reduced GO (RGO) synthesis was developed by using an ultrasonic probe and bath alternatively. RGO was prepared in acidic and neutral conditions. The products were characterized via FTIR, XRD, Raman spectroscopy, SEM and AFM. Well-exfoliated and smooth sheets without crumples are observed in GO. The RGO synthesized in acidic media had fewer layers and smaller crystallite size than that derived from neutral condition. Electrochemical investigations revealed higher effective surface area and better electrocatalytic activity for the RGO synthesized in acidic media (RGO1). The electrochemical sensing ability of the glassy carbon electrode modified with RGO1 (RGO1/GCE) towards dopamine (DA) was examined using cyclic and differential pulse voltammetry methods. The evaluation of the pH and scan rate effect on the DA electrochemical response confirmed a reversible electrocatalytic pH-dependent oxidation reaction, controlled by a mixed adsorption-diffusion process at the RGO1/GCE. Retained low disorders on the basal plane and high defect on the edge sites of the layers have provided high electrocatalytic activity for RGO1 that make it suitable for (bio) sensing applications.Graphical abstract: [ABSTRACT FROM AUTHOR]

Bimetallic Co-Ni catalysts in the composition range Co(1−x)Nix with x = 0.0, 0.2, 0.3, 0.4, 0.5, 0.6, 0.8 and 1.0, with total metal loading of 15% w/w and supported on TiO2-P25, have been prepared by chemical reduction of the metal acetates by glucose in aqueous alkaline medium and characterized by XRD, TEM, TPR, XPS and H2-TPD techniques. Selective hydrogenation of cinnamaldhyde (CAL) to hydrocinnamaldehyde (HCAL), cinnamyl alcohol (COL) and hydrocinnamyl alcohol (HCOL) has been investigated at 20 bar pressure, in the temperature range 120-140 °C. Co/Ni crystallite sizes in the range 6.0 ± 1 nm are observed by TEM. TPR and XPS results indicate the formation of nanoscale Co-Ni alloys, which tend to weaken M-H bond strength, as revealed by H2-TPD measurements. Ni/TiO2 displays very high conversion of CAL (86.9%) with high selectivity (78.7%) towards HCAL formation at 140 °C. Co/TiO2, on the other hand, exhibits relatively lower CAL conversion (55%) and higher selectivity (61.3%) for COL formation at the same temperature. However, bi-metallic Co-Ni catalysts in the composition range x = 0.3-0.6 display very high conversion (> 98%) due to alloy formation and weakening of M-H bonds. Bimetallic Co0.7Ni0.3 catalyst displays high conversion of CAL (98.1%) and high selectivity (82.9%) towards HCOL. Overall CAL hydrogenation activity at 140 °C, when expressed as TOF, displays a maximum value at the composition Co0.5Ni0.5. Activity and selectivity patterns have been rationalized based on the reaction pathways observed on the catalysts and the influence of Co-Ni alloy formation and M-H bond strength. Thus, a synergetic effect, originating from an appropriate composition of base metal catalysts and reaction conditions, could result in hydrogenation activity comparable with noble metal based catalysts. [ABSTRACT FROM AUTHOR]

Highly-dispersed copper nanoparticles (Cu NPs) were fabricated on the surface of reduced graphene oxide via direct hydrazine hydrate reduction of Cu2+ in aqueous solution. Scanning electron microscope and transmission electron microscope images show that the Cu NPs are distributed on the surface of graphene nanosheets, and the average particle size was about 40 nm. The Cu NPs supported on graphene have high reaction activity for the oxidation of toluene to corresponding benzaldehyde. It was found that the selectivity reached 66.5% and the conversion of toluene reached 11.5%. [ABSTRACT FROM AUTHOR]

Recent developments in catalytic reduction with H2 of glycerol, which is a by-product of biodiesel manufacture, and the involved chemistry are summarized and reviewed. There are more than ten potential C3 products of glycerol reduction. Among them, 1,2-propanediol can be obtained in very high yield and the production from glycerol is now commercialized. Production of 1,3-propanediol, allyl alcohol and propylene are now possible in > 60%, > 90% and > 80% yield, respectively. Key reaction steps are metal-catalyzed dehydrogenation/hydrogenation, acid-catalyzed dehydration, carbonyl-induced dehydration, metal-catalyzed direct hydrogenolysis and deoxydehydration. The 2-Propanol and small-ring compounds (oxetane, propylene oxide) cannot be produced from glycerol by combinations of these key reaction steps, and no catalytic system is known at present, although the conversion reactions have minus ∆G°. [ABSTRACT FROM AUTHOR]

New materials based on electric arc furnace (EAF) dust have been produced via temperature-programmed reduction using hydrogen gas at different temperatures. Scanning electron microscopy, thermal analysis, X-ray diffraction, and Mössbauer spectroscopy suggested that the EAF dust is reduced by hydrogen at 600 and 700 °C producing reduced iron, e.g., iron (II) and iron metallic, magnetics and more active catalytic phases. The new materials show magnetic behavior as well as EAF starting material. Electron paramagnetic resonance studies using N-t-butyl-α-phenylnitrone as a trapped radical agent were performed showing characteristic signals related to paramagnetic species produced exclusively by the interaction of catalysts with hydrogen peroxide (H2O2). The new magnetic materials were successfully used for pollutant removal by adsorption followed by oxidation of model dyes such as methylene blue and indigo carmine. In addition, the great advantage of these materials is that they may be easily recovered magnetically and reused. [ABSTRACT FROM AUTHOR]

Ni-Zn alloy with various compositions of zinc was synthesised using a sodium borohydride-assisted chemical reduction method. The as-synthesised Ni-Zn alloy samples were annealed at 673 K for 2 h in nitrogen atmosphere. The atomic absorption spectroscopy measurement reveals the zinc-rich composition in all alloy samples. Field emission scanning electron microscopy shows that the surface morphology of Ni-Zn alloys has a flake-like nature. The X-ray diffraction pattern of as-synthesised samples shows the presence of nickel hydroxide while the annealed samples show formation of Ni2Zn11 phase. The phase transition temperature of as-synthesised Ni-Zn alloy was observed using differential scanning calorimetry and crystallization temperature changes with zinc composition was also examined. The room temperature magnetic behaviour of both as-synthesised and annealed samples was studied using vibrating sample magnetometer. This shows that as-synthesised samples have a weak ferromagnetic nature and annealed samples have a soft ferromagnetic nature. The decreasing magnetization value and Curie temperature with zinc composition was observed. The catalytic activity of Ni-Zn alloy was studied for the reduction of 4-nitrophenol. The rate constant value changes with zinc composition in the alloy. [ABSTRACT FROM AUTHOR]

The electrochemical reduction of S-phenyl benzenethiosulfonate (1) was investigated by cyclic voltammetry at different scan rates (0.1–60 V/s) using glassy carbon electrodes in three different solvents; acetonitrile, dimethyl sulfoxide, and dimethyl formamide. The initial electron transfer (ET) to the investigated compound follows a concerted process with the formation of a radical/ion pair before complete dissociation (“sticky” dissociative ET mechanism). Application of classical and “sticky” dissociative electron transfer theories, as well as theoretical calculations supported the proposed ET mechanism. The theoretical calculations showed that the LUMO of S-phenyl benzenethiosulfonate and SOMO of its reduced form are homed on the S-SO2 chemical bond with a low contribution on the rest of the molecule. This indicates that the incoming electron is directly injected to the chemical bond causing its cleavage. The controlled potential electrolysis of the investigated compound, monitored by high performance liquid chromatography and cyclic voltammetry, indicated the consumption of one electron per molecule, and final formation of diphenyl disulfide and phenyl sulfinate. All experimental and theoretical findings were used to propose the full reduction mechanism. Also, a solvent effect was observed on certain parameters including reduction peak potentials, transfer coefficient values, the strength of the interaction between the ion/radical fragments, and the chemical reaction processes following the first ET. This solvent effect was rationalized by comparison of the solvent’s properties. [ABSTRACT FROM AUTHOR]

Cobalt nanocrystals with different morphologies and magnetic properties were prepared from three cobalt(II) heterocyclic amine precursors in alcoholic solution by a chemical reduction route. Complexes of cobalt(II) with heterocyclic amines such as pyridine, piperidine, and piperazine were reacted with hydrazine at 70 °C and pH 10-12. The obtained cobalt metallic nanocrystals (Co1-Co3) were characterized by using infrared (IR) spectroscopy, X-ray powder diffraction analysis, scanning electron microscopy, and vibrating-sample magnetometry. Powder X-ray diffraction patterns revealed the presence of two phases of hcp-Co and fcc-Co nanocrystals in the resulting cobalt metal. By changing the precursors, significant variation of magnetic properties and crystallite size was observed in Co1-Co3. This work provides new insight into the synthesis of metallic nanocrystals via chemical reduction of metal complexes and their magnetic properties. Graphical Abstract: [ABSTRACT FROM AUTHOR]

The acidity of Zr-incorporated large pore cubic mesoporous silicate, KIT-5, with Fm3m symmetry was explored as catalyst in the Hantzsch reaction for preparation of 1,4-dihydropyridine (DHP) derivatives, Meerwein-Ponndorf-Verley (MPV) reduction of 4- tert-butylcyclohexanone, and Prins reaction of citronellal. The catalyst showed ~82-94 % selectivity for formation of DHP derivatives based on substituted benzaldehydes. For the intramolecular cyclization of citronellal, the activity and isomer selectivity increased with Zr content. Both these reactions proceeded to nearly total conversion in relatively short reaction times of 3 h and 30 min, respectively. In sharp contrast, MPV reduction of 4- tert-butylcyclohexanone yielded 95 % conversion in 4 days, similar to those reported for Zr-TUD-1. [ABSTRACT FROM AUTHOR]

This study deals with reduction of ortho and para-nitroaniline by NaBH with silver nanoparticles (AgNPs), synthesized by use of a green method, as catalyst. In the synthesis of the AgNPs an aqueous extract of Tamarindus indica ( T. indica) seed coat was used as a reducing and capping agent. The effects of extract concentration and reaction time on formation of the AgNPs were studied by use of UV-visible (UV-Vis) spectroscopy. The stable AgNPs were characterized by dynamic light scattering (DLS), measurement of zeta potential, Fourier-transform infrared (FTIR) spectroscopy, and high-resolution transmission electron microscopy (HRTEM) with energy-dispersive spectrum analysis. Appearance of a yellow color and generation of a surface plasmon resonance peak in UV-Vis spectroscopy confirmed formation of the AgNPs. The FTIR results suggested that the phytoconstituents of T. indica seed coat extract are responsible for reduction of the Ag and protection of the AgNPs. HRTEM studies showed the size of the AgNPs was approximately 30-50 nm; their shape was distorted spherical. The TEM results were consistent with DLS study. The catalytic efficacy of stable AgNPs in the reduction of o and p-nitroaniline was studied by UV-Vis spectroscopy. The calculated rate constants ( k) for catalytic reduction of o and p-nitroaniline by AgNPs were 2.43 × 10 and 6.22 × 10 S. [ABSTRACT FROM AUTHOR]

An approach for significantly suppressing NO formation in reduction of NO by NH over VO-WO/TiO (VWT) catalyst has been studied by coating different amounts of a Fe-exchanged zeolite (FeZ) onto the catalyst. FeZ-promoted VWT samples were characterized using N sorption, X-ray diffraction (XRD) analysis, and NH adsorption/desorption techniques to understand the primary role of FeZ in lowering NO production levels. At high temperatures (≥450 °C), VWT gave NO production with high concentrations, while NO formation was noticeably reduced when using FeZ-promoted catalysts, which also showed somewhat lower NO removal activities (<5 %) at all temperatures. N sorption and XRD measurements revealed no perceptible physical or chemical alterations of each constituent, even in VWT catalysts after FeZ coating following high-temperature calcination. Adsorption of NH on unpromoted and FeZ-promoted catalysts and subsequent desorption yielded very complicated spectra for NO that might primarily come from NH oxidation, and the interaction between V-NO species at temperatures >580 °C. NO on neighboring sites seems to be produced via decomposition of NO generated at lower temperatures. The FeZ in the promoted VWT catalysts could be responsible for NO decomposition and NO reduction with unreacted NH at temperatures >400 °C, thereby significantly lowering NO emission levels. This promotional effect bodes well for use in many industrial deNO applications. [ABSTRACT FROM AUTHOR]

Synthesized magnetite (FeO) nanoparticles, with an average crystallite size of 8 and 22 nm, were investigated for Fischer-Tropsch synthesis reaction to clarify the effects of iron crystallite size and a potassium promoter. The larger crystallite size of FeO without the potassium promoter showed an increased CO conversion with a lower selectivity of C+ and olefinic hydrocarbons. This was mainly attributed to the enhanced reduction degree and an abundance of active edge sites of cube-like morphology. However, a modification of FeO nanoparticles with the potassium promoter significantly changed the product distribution by increasing C+ and olefinic hydrocarbons with much higher CO conversions. The enhanced activity on the large crystallite size of K-modified FeO was mainly attributed to an enhanced secondary reaction of olefins formed on the active iron carbide sites. The positive effect of the potassium promoter was much significant on the larger FeO nanoparticles due to an abundant presence of potassium promoter on the outer surface of the large FeO nanoparticles with a bigger inter-particular pore diameter for an easy mass transport. [ABSTRACT FROM AUTHOR]

Consecutive reduction of acetic acid to ethanol was investigated looking for advantageous bimetallic catalysts for the processing of volatile fatty acids that can be produced by thermochemical or biological biomass degradation. The reactant acid was hydrotreated in a flow-through reactor at 21 bar total pressure and 200-380 °C over fumed silica loaded with Ni main metal and Cu, Zn, Cd, Ga, In, Sn modifying metals. By varying these bimetallic composites prepared by solid-state co-reduction of admixed metal oxide precursors, the characteristic hydrodecarbonylation activity of nickel can be completely eliminated and a high ethanol yield can be attained selectively with the exception of Zn and Cd. The low boiling point and high volatility of these two elements in group IIb exclude formation of stable bimetallic composition. Indium and tin doping were found to be the most efficient. The lower reduction temperature of the InO was found to be the advantage of novel In doping compared to well-known Sn-admission using oxide precursors for introduction of the second metal. [ABSTRACT FROM AUTHOR]

This study aims is to investigate the influence of different concentrations of Kappaphycus alvarezii ( K. alvarezii) for the synthesis of Cu@CuO core-shell nanoparticles (NPs) in aqueous solution. The core-shell NPs were prepared by a chemical reduction method using K. alvarezii, CuSO·5HO, NaOH, ascorbic acid, hydrazinium hydroxide, as stabilizer, copper precursor, pH moderator, antioxidant and reducing agent under 120 °C temperature, respectively. Formation of Cu@CuO-NPs was determined by UV-Vis spectroscopy where surface plasmon absorption maxima can be observed at 390-590 nm. The synthesized core-shell NPs were also characterized by X-ray diffraction. Moreover, the morphology and structure of the K. alvarezii/Cu@CuO-NPs were investigated by TEM, FESEM and EDXRF. The Fourier transform infrared spectrum suggested the complexation present between K. alvarezii and Cu@CuO-NPs. The study clearly showed that using various amounts of K. alvarezii leads to produce different ratios and sizes of Cu@CuO NPs. The size of the Cu@CuO-NPs decreased as the amount of K. alvarezii was increased. The ratio of Cu@CuO increases with the increasing concentration of K. alvarezii until 0.2 wt%. [ABSTRACT FROM AUTHOR]

2,3-Dihydro-5,8-dihydroxynaphthalene-1,4-dione (naphthazarin) (2) is used for the first time as a biologically important reagent in the synthesis of gold nanoparticles in water-methanol medium through the chemical reduction of HAuCl at room temperature without using any capping agents other than naphthazarin. The ratio of HAuCl and naphthazarin played a vital role in controlling the shape and size of gold nanoparticles. Three samples with significant differences in sizes (range of 10-200 nm) have been prepared through increasing the initial naphthazarin/HAuCl molar ratio from 50 to 200. The size, distribution, and formation of gold nanoparticles were confirmed by transmission electron microscopy, Fourier transform infrared spectroscopy, and UV-Visible absorption spectroscopic measurements. Graphical Abstract: 2,3-Dihydro-5,8-dihydroxynaphthalene-1,4-dione (naphthazarin) as a green reagent is introduced for the first time in the synthesis of gold nanoparticles in water-methanol medium through chemical reduction of AuCl by a suitable molar ratio of this reagent to HAuCl at room temperature without using any capping agents other than naphthazarin. The ratio of HAuCl and naphthazarin played a vital role in controlling the shape and size of gold nanoparticles. The size, distribution, and formation of gold nanoparticles were confirmed by transmission electron microscopy and Fourier transform infrared spectroscopy. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A series of Ni-B amorphous alloys supported on γ-AlO was prepared by an impregnation chemical reduction method and tested in the selective hydrogenation of ethyl benzoate to ethyl cyclohexane carboxylate. The effect of different metal additives on the activity of the supported Ni-B amorphous alloys was investigated. It was found that the addition of small amounts of Pd to Ni-B amorphous alloy supported on γ-AlO could markedly improve its activity and the yield of ethyl cyclohexane carboxylate can reach 88.1 % under the optimal reaction conditions. Furthermore, this catalyst could be recycled eight times without appreciable loss of its initial activity, much better than the unsupported one. The Ni-Pd-B amorphous alloy was proven to be highly dispersed on the surface and in the pores of γ-AlO, resulting in its larger BET area, more active Ni species, better stability, and hence accounting for its good catalytic performance. [ABSTRACT FROM AUTHOR]

In this study the alkoxide-independent pathway of reductive elimination of C-O from palladium ( p-cyanophenyl) neopentoxide complex in THF at 47 °C was investigated theoretically by use of density functional theory and the solvent polarized continuum model. On the basis of experimental results a two-pathway mechanism had been proposed: a concerted process (path a) and a two-step process (path b) initiated by inner-sphere attack of the alkoxide ligand on the ipso-carbon atom of the palladium-bound aryl group (step 1) then Pd-C heterolysis to form p-neopentoxybenzonitrile (step 2). The activation energies of the two pathways were calculated by use of the quantum mechanical approach and compared with each other and with experimental results. [ABSTRACT FROM AUTHOR]

A facile and efficient method for reductive N-alkylation of nitrobenzenes with alcohols catalyzed by the bimetallic catalyst CuCr/γ-AlO, in a fixed-bed reactor, was successfully established. X-ray diffraction, temperature-programmed reduction, and X-ray photoelectron spectroscopy were used to characterize the catalyst. Introduction of Cr to Cu/γ-AlO was found to substantially enhance the dispersion of Cu particles, which are believed to be the active sites for the reductive N-alkylation. The reaction conditions were optimized and a series of alcohols and nitrobenzenes were converted into N-alkylated anilines in more than 90 % yield by use of this catalyst. [ABSTRACT FROM AUTHOR]

Supported Ni-B and Ni-B-K amorphous alloy catalysts were prepared by chemical reduction method and characterized by nitrogen adsorption-desorption, power X-ray diffraction, selected area electron diffraction, and scanning electron microscopy. The prepared catalysts were tested in liquid phase hydrogenation of adiponitrile in the absence of ammonia under mild condition. Ni-B-K/SiO exhibited high activity and selectivity toward 6-aminocapronitrile and 1,6-hexanediamine. [ABSTRACT FROM AUTHOR]

To increase the folding rate and gain insight into the folding process, the lysozyme was selected as a model protein and refolded by the aromatic thiols (ArSH) alone and by redox buffers glutathione/glutathione disulfide (GSH/GSSG). The optimum folding conditions, including the concentration of aromatic thiols, and the composition and pH of buffer solutions, were investigated. Attempts were first made to understand how aromatic thiols alone affect the folding performance of disulfide-containing proteins. The results showed that redox buffers of both aliphatic thiols and aromatic thiols can enhance the folding rate and yield of denatured reduced proteins effectively. However, the folding rates by aromatic thiols were up to 2-15 times greater than those with GSH/GSSG under various pH values (6.0-9.0). More importantly, the research demonstrated that the aromatic thiols alone can also increase the rate of proteins folding significantly at wide pH values, which has never been previously reported. It is expected that the research will provide a novel method for the folding of disulfide-containing proteins. [ABSTRACT FROM AUTHOR]

Several Cu-based catalysts were prepared and investigated for reductive alkylation of p-nitroaniline with butanone. Performance of Cu-Cr-Ca/γ-AlO was excellent. N, N'-di- sec-butyl- p-phenylenediamine was obtained in approximately 98.0 % yield under mild conditions. Results from XRD, XPS, and NH-TPD characterization revealed that introduction of Cr remarkably improved the dispersion of Cu active sites whereas addition of Ca partly reduced the strong acid capacity of the catalyst. The reaction conditions, including reaction temperature and hydrogen pressure, were also optimized and the catalyst performed well for 100 h under the optimized conditions. [ABSTRACT FROM AUTHOR]

Three novel 1,8-naphthalimide derivatives containing indole and indoline were synthesized through Fischer indole synthesis, reduction, and alkylation. Two reference dyes with similar structures to the three novel dyes were also prepared. The absorption and fluorescence spectra of these dyes in a variety of solvents were investigated. In addition, fluorescence of these dyes in solid state was also measured. Intramolecular charge transfer was confirmed within the new dyes by virtue of shifts in emission maximum with increasing solvent polarity. Intermolecular close contacts and lateral intermolecular hydrogen bonding interactions between neighboring columns lead to fluorescence wavelength shift, short in the solution and long in the solid state. [ABSTRACT FROM AUTHOR]

Sn nanoparticles (NPs) were synthesised via chemical reduction. Trisodium citrate dihydrate and mixtures of trisodium citrate dihydrate and 1,10-phenanthroline monohydrate were used as capping agents for the synthesis. When a specific amount of trisodium citrate dihydrate (3.4 × 10mM) was solely added, very fine particle sizes and excellent suppression of aggregation were achieved in the dried samples. When 5 mM of 1,10-phenanthroline monohydrate was used in combination with trisodium citrate dihydrate (at the optimum concentration of 3.4 × 10mM), the particle refining and the suppression of aggregation were further improved. The nano-solder paste prepared by mixing the synthesised Sn NPs with a commercial flux exhibited stable reflow soldering characteristics. The formation of an intermetallic layer, similar to that observed when commercial solder pastes containing micron-sized powders were used, was seen when soldering was carried out with the solder paste containing the synthesised Sn NPs. [ABSTRACT FROM AUTHOR]

A series of platinum(II) complexes of reduced amino acid esters Schiff bases were synthesized as potential anticancer agents and characterized by H NMR, EA, IR, and molar conductivity. These compounds were tested for their DNA interaction with salmon sperm DNA by ultraviolet spectrum and CD spectrum, and their in vitro anticancer activities have been validated against HL-60, KB, BGC-823, and Bel-7402 cell lines by MTT assay. The cytotoxicity of complexes 5d and 5f are better than cisplatin against Bel-7402 cell lines, and show a close cytotoxic effect against HL-60 cell line. [ABSTRACT FROM AUTHOR]

Ruta chalepensis extract (Ruta) was tested as a corrosion inhibitor for steel in 1 M HCl. Weight loss measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) were used. The inhibiting action increases with increasing concentration of the tested inhibitor. Efficiency is highest, 87 %, for 3.5 g/L Ruta extract. It acts on the cathodic domain without modifying the reduction mechanism. We note good agreement between gravimetric and electrochemical methods (potentiodynamic polarisation and EIS). Polarization measurements also show that Ruta extract is a good mixed inhibitor. The effect of temperature on the corrosion behaviour of steel in 1 M HCl was also studied in the temperature range 298-338 K. Thermodynamic data for activation were determined. Ruta extract is adsorbed on the steel surface in accordance with a Temkin adsorption model. [ABSTRACT FROM AUTHOR]

Acid hydrolysis of corn stover under microwave radiation by adding four metal salt co-catalysts (ferrous sulfate, copper sulfate, zinc sulfate, and manganese sulfate) to produce reducing sugar was investigated. The influences of microwave power, reaction time, sulfuric acid concentration, and co-catalyst concentration on the yield of reducing sugar were studied. The results show that the catalytic effects of ferrous sulfite and copper sulfate are more obvious for the yield of reducing sugar compared with only dilute acid hydrolysis with microwave radiation. Long-time microwave irradiation resulted in secondary hydrolysis, generating small-molecule compounds and decreasing the yield of reducing sugar. The reducing sugar yield was increased by decreasing the hydrolysis reaction time and microwave radiation power. In terms of reducing sugar yield, the four kinds of metal salt co-catalyst act in the order: ferrous sulfate > copper sulfate > sulfuric acid zinc sulfate > manganese sulfate. At concentration of 3.0 %, the best was ferrous sulfate, producing yield of 35.10 %. [ABSTRACT FROM AUTHOR]

A simple and sensitive spectrophotometric method for the determination of nimesulide in bulk, in pharmaceutical dosage form, and in biological fluids was developed. The method is based on the reduction of the nitro group of nimesulide by zinc and hydrochloric acid followed by diazotization, and coupling with orcinol in basic medium to form a stable chromophore, which absorbs at 465 nm. The method showed a good linearity in the range 0.4-4.0 μg mL. Partial least square modeling as a powerful multivariate statistical tool is also applied, compiled, and compared for determination of nimesulide. The experimental matrix for the partial least square calibration method was designed with 24 samples. The cross-validation was used for selecting the number of factors. The root mean square error prediction (RMSEP) and the relative error of prediction (REP %) were 0.089 and 3.95, respectively. The developed method is free from the interference of common excipients used in pharmaceutical dosages. The method was also used for the determination of nimesulide in pharmaceutical dosages as well as in human serum and urine samples. [ABSTRACT FROM AUTHOR]

The effect of the impregnation and co-precipitation-kneading methods on the catalytic performance of the Ni/H-ZSM-5 catalyst was evaluated via catalytic reductive deoxygenation of cyclohexanone in a fixed bed. The catalysts were characterized by X-ray diffraction, nitrogen adsorption, and NH-temperature programmed desorption. A sharply acidic and textural change was observed on the catalysts prepared by the different methods, while the metal active phase structure was almost the same. The results of the cyclohexanone reductive deoxygenation reaction indicated that the catalyst based on the co-precipitation-kneading method afforded a higher yield of cyclohexane, and thus proved that the co-precipitation-kneading method is suitable for the preparation of a bi-functional catalyst. [ABSTRACT FROM AUTHOR]

The electrochemical behavior of complexes of fatty amides, synthesized from vegetable oil, with Cu(II) has been investigated. In this study, a platinum electrode was used in presence of DMSO as a medium. Reduction of Cu(II)/fatty amides complex was found with quasi-reversible reaction. The peak potential of voltammetric behavior of fatty amides is about −0.77 V at a scan rate v = 0.1 V s versus Ag|Ag electrode. This study shows that Cu(II)-fatty amides complex is poorly adsorbed on the electrode surface. Additionally, the copper complex form of fatty amides has a more stable structure than pure fatty amides to form the electrochemical reduction of the complex. [ABSTRACT FROM AUTHOR]

An improved method was developed for preparation of 5,6,7,8-tetrahydrofolic acid (THF) and calcium-5-methyltetrahydrofolate (5-MTHF-Ca) by reduction of folic acid using KBH catalyzed by Pb(NO). The yields of THF and 5-MTHF-Ca were 56.5 and 42.7 %, respectively. A convenient method for measurement of THF and 5-MTHF-Ca using liquid chromatography-mass spectrometry (LC-MS) was also established, enabling analysis of those folates within 10 min without application of gradient elution. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis of SmInTaO and its photocatalytic activity on the degradation of crystal violet dye and reduction of Cr(VI) ions in aqueous solution. SmInTaO was prepared by sol-gel method at 1,200 °C. For comparison purposes, SmInTaO was prepared also by solid-state reaction at 1,400 °C. The evolution of the crystalline phases of the sol-gel sample with the annealing temperature was followed by X-ray diffraction. The cubic crystalline structure of SmInTaO was determined by Rietveld refinement method. Specific surface area was 5 mg for sol-gel sample and 1 mg for solid-state sample, whereas energy band gap was around 3.5 eV. SmInTaO prepared by sol-gel method showed better photocatalytic activity than SmInTaO prepared by solid-state reaction for the mineralization of crystal violet dye and reduction of Cr(VI) solution under UV-light irradiation. [ABSTRACT FROM AUTHOR]

This paper characterizes the integrated activity of fresh and used catalysts on the selective catalytic reduction of NO x using CH. The synthesised K-Ag/AlO catalysts exhibited a promotional effect on deNO x activity in the presence of SO. In addition, 130 h of time-on-stream reactions demonstrated the thermal and mechanical stability of the synthesised materials. A TEM analysis and diffraction patterns demonstrated the sintering of finely dispersed particles to ~0.5 micron size clusters by sulphation. Furthermore, under reaction conditions, the de-sulphation initiated the re-dispersion of the Ag clusters to different sized particles. The TPD studied demonstrated the strong adsorption sites for methane and formation of R-SO x compounds. This surface modification in the SO feed stream is considered to be the reason for the promotional effect on the deNO x reaction. [ABSTRACT FROM AUTHOR]

VMoO powder was obtained by reducing acidified vanadate and molybdate solution at 60 °C by passing hydrogen sulfide gas through the solution. The obtained multicomponent mixed oxide was used as an anode material for the first time in the literature and tested in the solid oxide fuel cell for the temperatures of 700, 750, and 800 °C and the values of 0.38 ± 0.06 A/cm and 0.18 ± 0.03 W were respectively obtained as current density and power at 800 °C in the cell. [ABSTRACT FROM AUTHOR]

Chemoselective synthesis of 2-nitroalkanols catalyzed by electro-generated base (EGBs) in the presence of acetonitrile and lithium perchlorate has been studied by cyclic voltammetry and controlled potential electrolysis techniques. Cathodic reduction of nitromethane at platinum cathode produces organic anion which acts as EGBs and undergoes condensation with carbonyl group of substituted aldehydic substrate to produce 2-nitroalkanols in 75-85 % yields. The controlled nucleophilicity of EGBs in organic solvent during electrochemical reaction makes it chemoselective which is a unique feature of this work. [ABSTRACT FROM AUTHOR]

An efficient synthesis of N-mono-substituted β-amino tertiary thiols by reductive ring-opening of 3-thiazolines, obtained by use of the Asinger reaction, is described. This synthesis be regarded as a complementary approach for aminolytic ring-opening of thiiranes. [ABSTRACT FROM AUTHOR]

A series of water-soluble platinum(II) complexes of reduced amino acid Schiff bases were synthesized as potential anticancer agents and characterized by H NMR, EA, MS, IR, and molar conductivity. These compounds were tested for their DNA interaction with salmon sperm DNA, and their in vitro anticancer activities have been validated against HL-60, KB, BGC-823, and Bel-7402 cell lines by the MTT assay. The cytotoxicity of one complex ( 5g) is better than that of cisplatin against BGC-823 and HL-60 cell lines, and show close cytotoxic effect against Bel-7402 cell line. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The reduction of dodecyl iodide, as model compound, with a series of lanthanoid (Ln) metals in the presence of catalytic amounts of samarium diiodide (SmI) has been investigated in detail. The reducing activity of SmI/Ln and the kinds of reduced products were found to be dependent on the individual Ln, but not on SmI. [ABSTRACT FROM AUTHOR]

The promoting effect of ultrasound on the selective reduction of nitroarenes to N-arylhydroxylamines by use of Zn in an environmentally benign CO-HO system has been demonstrated. The yield of N-phenylhydroxylamine reaches 95 % when the reaction is carried out with a Zn-to-nitrobenzene molar ratio of 2.2 under ultrasound (40 kHz) at 25 °C and normal pressure of CO for 60 min. Application of ultrasound to the reaction has the advantages of higher yield of N-arylhydroxylamines, shorter reaction time, and consumption of less Zn. [ABSTRACT FROM AUTHOR]

A continuous process for reduction of aromatic ketones to the corresponding aromatic alkanes over CuCr/γ-AlO was established in a fixed-bed reactor. A series of aromatic ketones were examined, and all of the corresponding aromatic hydrocarbons were obtained in more than 95% yield. The catalysts were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and H-temperature programmed reduction. Cu is believed to be the active center of the catalyst. Cr was found to have an important effect on catalytic activity and stability. [ABSTRACT FROM AUTHOR]

Effective diffusivity of gases is an important property when modeling the physicochemical processes occurring in a pellet. Calculating effective diffusivity in a pellet composed of a mixture of particles is a difficult task. In this paper, a theoretical model is presented in order to describe the diffusion of gases in a porous pellet made up of a mixture of two kinds of solid grain. Solid grains can either be fully dense and thus non-porous or contain pores, with a grain being sub-divided into sub-grains. The results predicted by the model have been evaluated and validated by use of experimental data obtained by reduction of cuprous sulfide in the presence of lime. Finally, the effects of structural properties and operating conditions on the effective diffusivity of the gases in the pellet have been evaluated. [ABSTRACT FROM AUTHOR]

The effects of Ru on the self-reducibility of Ru-doped Ni/MgAlO catalysts, which do not need pre-reduction treatment with H, were investigated in the steam reforming of methane (SRM). The Ru-promoted Ni/MgAlO catalysts with various amounts of Ru (0-0.5 wt%) were prepared by stepwise impregnation and co-impregnation methods using hydrotalcite-like MgAlO support. For comparison, Ru/MgAlO catalysts with the same amount of Ru were also prepared by the impregnation method. The catalysts were characterized by the N-sorption, XRD, H-TPR, H-chemisorption, and XPS methods. Ni/MgAlO catalyst in the presence of even the trace amount of Ru (Ru content ≥0.05 wt%) showed higher conversion without pre-reduction as compared to Ru/MgAlO catalysts in SRM under the same conditions. The self-activation of Ru-Ni/MgAlO catalysts is mainly attributed to the spillover of hydrogen, which is produced on Ru at first and then reduces NiO species under reaction conditions. Besides, Ru doping makes the reduction of NiO easier. The stepwise impregnated Ru/Ni/MgAlO catalyst produced superior performance as compared to co-impregnated Ru-Ni/MgAlO catalyst for SRM. [ABSTRACT FROM AUTHOR]

Dealumination of the small-pore zeolite chabazite (CHA) was performed with ammonium hexafluorosilicate under solid and liquid-state conditions to increase the Si-to-Al ratio from 2.0 to 6.0. In the solid state, the mesopore fraction increased with repeating hydrothermal synthesis at 423 K, which was confirmed by nitrogen adsorption-desorption. In the liquid state, the formation of mesopores decreased substantially and the resulting CHA had an Si-to-Al ratio of ca. 5. The result of desorption of NO-NO from the Cu ion-exchanged dealuminated CHA in the solid state indicated that the presence of mesopores reduced NO-NO adsorption and desorption of NO occurred at 383 and 683 K whereas for the high-silica analog SSZ-13 desorption of NO occurred mostly at 473 and at 673 K. [ABSTRACT FROM AUTHOR]

A(PO)(OH) (A = Ca and Sr)-supported Pt catalysts were prepared and their catalytic activity in NO reduction were investigated. The Sr(PO)(OH)-supported catalyst had high catalytic activity in the CH-NO-O reaction; the activity was higher than that of the γ-AlO-supported catalyst at 300 °C. The basicity of the apatite supports would affect the chemical state of Pt on catalyst, resulting in promotion of NO reduction. [ABSTRACT FROM AUTHOR]

A series of LaSrCrRuO (0.1 ≤ x ≤ 0.5, 0.05 ≤ y ≤ 0.15) materials was prepared by the sol-gel method to develop alternative catalysts for propane steam reforming. Catalyst characteristics were evaluated using physicochemical methods including X-ray diffraction, Brunauer-Emmett-Teller methods, H temperature-programmed reduction, and thermogravimetry analysis (TGA). Effects of the amount of ruthenium (Ru) and strontium and the steam-to-carbon ratio (S/C) were investigated. An increase in Ru content led to increased propane conversion and H yield, especially below 700 °C. Dramatic enhancement of catalytic activity was observed with LaSrCrRuO under 600 °C, achieving propane conversion over 79% between 600 and 800 °C with maximum propane conversion and H yield of 98.3% and 63.3%, respectively. Also, good resistance to carbon formation for the LaSrCrRuO catalyst was confirmed by long-term testing and TGA analysis. [ABSTRACT FROM AUTHOR]