ICP Methods Research Articles

Nano Ag-doped magnetic-Fe3O4@mesoporous TiO2 core–shell hollow spheres: synthesis and enhanced catalytic activity in A3 and KA2 coupling reactions

Nano Ag-doped Fe3O4@mesoporous TiO2 core–shell hollow spheres (h-Fe3O4@m-TiO2/Ag) were efficiently prepared. They were fully characterized by FT-IR, FE-SEM, EDX, ICP, TGA, XRD, and BET methods. In addition, their magnetic properties were determined by means of the VSM method. Also, the ρ shell of the prepared hollow Fe3O4 micro-particles was calculated, being found just slightly lighter than that of solid sphere-like Fe3O4. The catalytic activity of this novel catalyst system was successfully examined as a novel catalyst system in A3 coupling reactions (aldehyde + amine + acetylene). This highly active magnetic catalyst was easily separated using an external magnet and re-used in five consecutive runs in the model reaction without appreciable loss of its catalytic activity.

Dehydration of fructose and glucose to 5-hydroxymethylfurfural over Al-KCC-1 silica

In this research, the influence of several factors such as reaction time, catalyst weight, temperature and different solvents on dehydration reaction of fructose and glucose to 5-hydroxymethylfurfural (HMF) was surveyed. Nanosphere Al-KCC-1 silica with fibrous morphology was manufactured and used as proficient and recyclable catalyst for this reaction. SEM, TEM, BET, XRD, EDX, elemental mapping, ICP and FT-IR spectroscopy methods were applied for characterization of the Al-KCC-1 (molar ratio Si/Al= 5, 40) catalysts. 162°C and 1h are the best conditions for the fructose dehydration. Under this situation HMF yield and selectivity are 92.9% and 94.5% respectively and fructose conversion is 98.4%. Also 170°C and 2h are the best conditions for the glucose dehydration. In this situation HMF yield and selectivity are 39.0% and 39.9% respectively and glucose conversion is 97.8%.

Effects of porosity and pore size distribution on mechanical strength reliability of industrial-scale catalyst during preparation and catalytic test steps

ABSTRACTThis paper investigates the effects of porosity and pore size distribution on crushing strength reliability of industrial-scale catalysts during their preparation and after reactor tests. Six supports, fabricated from two types of γ-alumina (type A, 119 m2/g; and type B, 343 m2/g), were used as starting materials. The supports were impregnated using a copper/zinc nitrate solution. The supports and catalysts, before and after the reactor tests, were characterized using XRD, ICP, SEM, and BET methods and were subjected to single particle crushing strength tests. The results revealed that the strength and Weibull modulus of all samples were decreased after the impregnation process due to the emergence of new flaws. In contrast, the partial sintering/necking of the interparticles during the reaction led to an increase of the crushing strength of the used catalysts. Furthermore, the porosity of the supports and catalysts from type A to type B γ-alumina were increased, leading to the strength decrease. Nevertheless, their Weibull modulus and strength reliability were increased due to the narrowing of pore size distribution in the range of mesopores.

The “Particle Proximity Effect” in Three Dimensions: a Case Study on Vulcan XC 72R

The “particle proximity effect” is a hypothesis claiming that Pt nanoparticles have higher ORR activity when they get closer to one another. In order to put this hypothesis under scrutiny, the “tool-box” approach was investigated in each process step by electron microscopy, ICP, and surface science methods. It is shown that particle size stability is brought about by a NaCl shell which can effectively be removed by washing with water. I.e., the “tool-box” synthesis with an additional washing step produces clean, closely spaced, and well-separated particles with interparticle distances necessary for the effect to occur. Despite this powerful synthesis route, a conclusive proof of the “proximity effect” could not be obtained. This is due to difficulties with catalyst film formation at higher platinum loadings on Vulcan XC 72R, suggesting that film deposition and drying methods have to be optimized for each catalyst loading separately and that a holistic approach is not very realistic.

Heavy metals screening of rice bran oils and its relation to composition

Rice bran oil contains beneficial compounds that contribute to its resistance to oxidation, as well as the health of consumers. However, concerns have surfaced in recent years related to the heavy metal content of rice and rice‐derived products. Rice is known to take up arsenic at a higher rate than other grain crops. The United Nations Food and Agriculture Organization recently set an acceptable limit of 0.2 μg/g of arsenic in rice, but no limits have been set for other edible products such as rice bran oil. Furthermore, arsenic levels in rice bran oil have not been thoroughly investigated. In this work we characterized both crude and refined rice bran oils, including detailed chemical composition, analysis of bioactive lipids, and a multi‐faceted approach for assessing prior oxidative history and stability of rice bran oils. We also analyzed levels of arsenic, lead, mercury, cadmium, and zinc. Metal concentrations were verified through two independent analytical laboratories. Concentrations of lead and cadmium in rice bran oils were generally low. Zinc concentrations were detectable but low relative to daily dietary allowances. Arsenic and mercury concentrations differed between the methods used to collect the data. We explore in this work the origins of these differences.Practical applications: Rice absorbs arsenic at a high rate relative to other crops, which has lead to increased consumer concern regarding toxic metal contaminants in rice and rice products. Despite the recent interest in this topic and limited work by the US FDA to test arsenic levels in rice, metal concentrations in rice bran oils have remained unexplored. In this work, we offer a complete characterization of crude and refined rice bran oils, including analysis of arsenic, lead, mercury, cadmium, and zinc. This work explores the utility of different ICP methods for heavy metals analysis, and the work described here may provide context for much of the recent press surrounding metal contaminants in rice.Heavy metal concentrations in eight different rice bran oils (µg/g). The relative sizes of metal ions are proportional to their most common ionic radius.

Mioceńskie poziomy tufitowe z otworów wiertniczych Busko (Młyny) PIG-1 i Kazimierza Wielka (Donosy) PIG-1

MIOCENE TUFFITE LEVELS FROM THE BUSKO (MŁYNY) PIG-1 AND KAZIMIERZA WIELKA (DONOSY) PIG-1 BOREHOLES Abstract. The paper presents detailed description of the tuffite levels from the Busko (Mlyny) PIG-1 and Kazimierza Wielka (Donosy) PIG-1 boreholes (Miocene, Carpathian Foredeep). Mineral and petrographic composition of the tuffites was examined with a polarizing microscope and a scanning electron microscope (SEM-EDS). Chemical composition of whole rock samples was determined with the ICP and INAA methods. Research has shown that the tuffite levels differ in terms of the chemical composition of glass, alkaline plagioclase content, grain size of the components and content of typical rock-forming minerals (e.g. biotite, pyroclastic quartz and potassium feldspar). Normal gradations and lamination of the tuffites indicate that they originated as a result of sedimentation of volcanic ash in marine conditions. Degree of preservation of pyroclastic minerals in the tuffites reflects changes in the geochemical environment of deposition. The first tuffite level above the evaporites, the most widespread and with characteristic chemical composition of pyroclastic components, can be applied in the correlation of deposits in the Carpathian Foredeep.

One-pot synthesis of core-shell Cu@SiO2 nanospheres and their catalysis for hydrolytic dehydrogenation of ammonia borane and hydrazine borane

Ultrafine copper nanoparticles (Cu NPs) within porous silica nanospheres (Cu@SiO2) were prepared via a simple one-pot synthetic route in a reverse micelle system and characterized by SEM, TEM, EDX, XRD, N2 adsorption-desorption, CO-TPD, XPS, and ICP methods. The characterized results show that ultrafine Cu NPs with diameter of around 2 nm are effectively embedded in the center of well-proportioned spherical SiO2 NPs of about 25 nm in diameter. Compared to commercial SiO2 supported Cu NPs, SiO2 nanospheres supported Cu NPs, and free Cu NPs, the synthesized core-shell nanospheres Cu@SiO2 exhibit a superior catalytic activity for the hydrolytic dehydrogenation of ammonia borane (AB, NH3BH3) and hydrazine borane (HB, N2H4BH3) under ambient atmosphere at room temperature. The turnover frequencies (TOF) for the hydrolysis of AB and HB in the presence of Cu@SiO2 nanospheres were measured to be 3.24 and 7.58 mol H2 (mol Cu min)−1, respectively, relatively high values for Cu nanocatalysts in the same reaction. In addition, the recycle tests show that the Cu@SiO2 nanospheres are still highly active in the hydrolysis of AB and HB, preserving 90 and 85% of their initial catalytic activity even after ten recycles, respectively.

The Sytykanskaya kimberlite pipe: Evidence from deep-seated xenoliths and xenocrysts for the evolution of the mantle beneath Alakit, Yakutia, Russia

Mantle xenoliths (>150) and concentrates from late autolithic breccia and porphyritic kimberlite from the Sytykanskaya pipe of the Alakit field (Yakutia) were analyzed by EPMA and LAM ICP methods. In P-T-X-f(O2) diagrams minerals from xenoliths show widest variations, the trends P-Fe#-CaO, f(O2) for minerals from porphyric kimberlites are more stepped than for xenocrysts from breccia. Ilmenite PTX points mark moving for protokimberlites from the lithosphere base (7.5 GPa) to pyroxenite lens (5–3.5 GPa) accompanied by Cr increase by AFC and creation of two trends P-Fe#Ol ∼10–12% and 13–15%. The Opx-Gar-based mantle geotherm in Alakit field is close to 35 mW/m2 at 65 GPa and 600 °C near Moho was determined. The oxidation state for the megacrystalline ilmenites is lower for the metasomatic associations due to reduction of protokimberlites on peridotites than for uncontaminated varieties at the lithosphere base. Highly inclined linear REE patterns with deep HFSE troughs for the parental melts of clinopyroxene and garnet xenocrysts from breccia were influenced by differentiated protokimberlite. Melts for metasomatic xenoliths reveal less inclined slopes without deep troughs in spider diagrams. Garnets reveal S-shaped REE patterns. The clinopyroxenes from graphite bearing Cr-websterites show inclined and inflected in Gd spectrums with LREE variations due to AFC differentiation. Melts for garnets display less inclined patterns and Ba-Sr troughs but enrichment in Nb-Ta-U. The 40Ar/39Ar ages for micas from the Alakit mantle xenoliths for disseminated phlogopites reveal Proterozoic (1154 Ma) age of metasomatism in early Rodinia mantle. Veined glimmerites with richterite – like amphiboles mark ∼1015 Ma plume event in Rodinia mantle. The ∼600–550 Ma stage manifests final Rodinia break-up. The last 385 Ma metasomatism is protokimberlite-related.

Improving hydrogen production via water splitting over Pt/TiO2/activated carbon nanocomposite

Mesoporous TiO2/AC, Pt/TiO2 and Pt/TiO2/AC (AC = activated carbon) nanocomposites were synthesized by functionalizing the activated carbon using acid treatment and sol–gel method. Photochemical deposition method was used for Pt loading. The nano-photocatalysts were characterized using XRD, SEM, DRS, BET, FTIR, XPS, CHN and ICP methods. The hydrogen production, under UV light irradiation in an aqueous suspension containing methanol has been studied. The effect of Pt, methanol and activated carbon were investigated. The results show that the activated carbon and Pt together improve the hydrogen production via water splitting. Also methanol acts as a good hole scavenger. Mesoporous Pt/TiO2/AC nanocomposite is the most efficient photocatalyst for hydrogen production compared to TiO2/AC, Pt/TiO2 and the commercial photocatalyst P25 under the same photoreaction conditions. Using Pt/TiO2/AC, the rate of hydrogen production is 7490 μmol (h g catal.)−1 that is about 75 times higher than that of the P25 photocatalyst.

ChemInform Abstract: Ruthenium Hydride Complex Supported on Multi‐Wall Carbon Nanotubes for Catalytic C—C Bond Formation via Transfer Hydrogenation.

Abstract In this work, the preparation, characterization and investigation of catalytic activity ruthenium hydride catalyst, [RuHCl(CO)(PPh3)3], supported on MWCNT in the synthesis of β,γ-unsaturated ketones via carbon–carbon bond formation are reported. In the first reaction step, the MWCNTs were modified with 1,2-ethanedithiol, and in a second reaction step, the catalyst was attached to MWCNTs via this linker. The catalyst was characterized by diffuse reflectance UV–vis and FT-IR spectroscopic techniques, SEM, ICP and elemental analysis methods. The catalyst was reused several times without significant loss of its catalytic activity.

Groundwater Formation Below Chernozem Soils - Effect of Mineral Fertilization, Rainy and Dry Periods

Abstract Chernozem soil samples from the east of Austria have been packed into columns in order to investigate the effects of mineral fertilization on the composition of water, released to deeper layers. A solution imitating NPK fertilization was added on top of water-saturated columns, and washed down with 150 cm3 portions (about 0.1 pore volumes) every day except weekends, for 2 months. The eluates were collected and analyzed by ICP and AAS methods. After about one pore volume, a strong peak in alkali, alkaline earths, and sulfate occurred in the eluates, due to ion exchange with the fertilizer solution. After this, most concentrations in the eluates approached a steady state again, but lower than the levels met before. After a period of drying, the release of K and S, as well as P in 2 of 3 cases, increased, whereas the release of Fe and Mn decreased. Before the eluates entered the sample collection vessels, ochre precipitation scavenged many solutes (Cr > Al > Pb > P > V > Fe), but left Mo-Sr-Mg-K-Se-B rather untouched.

Ruthenium hydride complex supported on multi-wall carbon nanotubes for catalytic C–C bond formation via transfer hydrogenation

In this work, the preparation, characterization and investigation of catalytic activity ruthenium hydride catalyst, [RuHCl(CO)(PPh3)3], supported on MWCNT in the synthesis of β,γ-unsaturated ketones via carbon–carbon bond formation are reported. In the first reaction step, the MWCNTs were modified with 1,2-ethanedithiol, and in a second reaction step, the catalyst was attached to MWCNTs via this linker. The catalyst was characterized by diffuse reflectance UV–vis and FT-IR spectroscopic techniques, SEM, ICP and elemental analysis methods. The catalyst was reused several times without significant loss of its catalytic activity.

Coordination ability of silver(I) with antimycins and actinomycins – Properties of the T-shaped chromophores

A comprehensive study of the coordination ability of the Ag(I) ion with biologically oriented synthetic derivatives of naturally occurring molecular targets of antimycins and actinomycins, with potential anticancer activity, is presented. The physical properties and molecular structures of the isolated series of 15 coordination compounds, depending on the experimental conditions, modelling the unique in vivo physiological environment, within relatively common utilized factors such as the pH of the medium, the type of solvent, the molar ratio of the metal to ligand (M:L) and more, were discussed. Electronic absorption, fluorescence, CD and vibrational spectroscopy, including IR- and Raman methods, nuclear magnetic resonance, mass spectrometric, X-ray diffraction, ICP and thermal methods were applied. Quantum chemical DFT calculations and NBO analysis were performed as well. The competitive contribution of the peptide residues in the naturally occurring antimycins and actinomycins to the observed polydentate chelation and the effect on the spectroscopic properties and unique T-shaped AgIX2Y, and AgIX3 polyhedra of the metal-chromophores were discussed.

Ozone Initiated Ni/Metal Oxide Catalyzed Conversion of 1,2-Dichlorobenzene to Mucochloric Acid in Aqueous Solutions

In aqueous systems, chlorinated hydrocarbons exhibit low chemical reactivity and nonbiodegradability due to its toxicity. Relative efficiencies of 1% and 5% Ni loaded on alumina, silica and titania as catalysts for conversion of 1,2-dichlorobenzene to muchochloric acid (MCA) were investigated at (20 ± 1) °C and ∼1 atm as function of time. All nickel loaded metal oxides gave good conversions and product selectivity toward MCA, with little mineralization. Ni/SiO2 showed superior conversion with selectivity of 89.9–100% toward MCA. The ozonation products were characterized by 1H NMR, IR, Mass and GC-MS, while the catalyst materials were characterized by BET, SEM, FT-IR, ICP, and XRD methods.

Synthesis and High Photocatalytic Activity of Zn-doped TiO2Nanoparticles by Sol-gel and Ammonia-Evaporation Method

Photocatalysis has been applied to decompose the waste and toxic materials produced in daily life and in the global environment. Pure TiO2 (Zn-TiO2-0) and Zn-doped TiO2 (Zn-TiO2-x, x = 3-10 mol %) samples were synthesized using a novel sol-gel and ammonia-evaporation method. The Zn-doped TiO2 samples showed high photocatalytic activity for the degradation of methylene blue (MB). The physicochemical properties of the samples were investigated using XRD, SEM, ICP, DLS and BET methods. In addition, the most important measurement of photocatalytic ability was investigated by a UV-vis spectrophotometer. The effects of the mol % of zinc ion doping in TiO2 on photocatalytic activity were studied. Among the mol % Zn ions investigated, the Zn-TiO2-9 sample showed the highest photoreactivity. This sample removed 91.4% of the MB after 4 h, while the pure TiO2 only removed 46.4% of the MB.

Efficient conversion of 1,2-dichlorobenzene to mucochloric acid with ozonation catalyzed by V2O5 loaded metal oxides

Ozone initiated oxidation of 1,2-dichlorobenzene (DCB) in aqueous system catalyzed by different loadings of V2O5 supported on metal oxides namely; Al2O3, SiO2 and TiO2 was investigated. Catalyst materials were characterized by different surface techniques including BET, TPD, SEM, FT-IR, ICP, and XRD methods. Mucochloric acid (MCA) was identified to be main oxidation product. The conversion and selectivity of MCA were compared. With 5% V2O5, all three supports gave 100% conversion and 100% selectivity after 5h ozonation. Conversion efficiency of the support was SiO2>Al2O3>TiO2 for 2h ozonation duration and 5% V2O5 loaded catalysts registered higher conversions than with 1% loaded. Probable reaction scheme is described.

Structural, Optical and Dielectric Studies On Pure and Doped LAlaninium Maleate Single Crystals

Good optical quality single crystals of pure and doped L-Alaninium Maleate (LAM) crystals have been grown. The crystals have been grown by slow evaporation method at a constant temperature of 35 C from its aqueous solution. The grown single crystals of pure and doped LAM were characterized by employing FTIR, SHG, ICP, Dielectric study and Xray diffraction methods.

Photodegradation of Pentachlorophenol Using NiO-Coupled NiTiO<sub>3</sub> Nanocomposites from Layered Precursor as Photocatalysts

NiO-coupled NiTiO3 nanocomposites have been synthesized by calcining a precursor dodecylbenzensulfonate (DBS) modified Ni-Ti LDH (DBS-Ni5Ti) and characterized by XRD, ICP, TG/DTA, SEM and DRS methods. The results show that the photocatalytic activity is gradually enhanced with increasing calcination temperatures, consistent with the marked increase in the content of NiTiO3 phase. The pentachlorophenol (PCP) degradation percentage over DBS-Ni5Ti-800 is up to 66%. The NiTiO3 phase in the nanocomposites may act as a major one of the photocatalytic active phases in the degradation of PCP under UV-light irradiation.

Structural and spectroscopic study of novel Ag(I) metal–organic complexes with dyes – Experimental vs. theoretical methods

Sixteen new metal–organic AgI-compounds of organic dyes are synthesized, isolated spectroscopic and structurally elucidated by means of single crystal and powder X-ray diffraction, high resolution ESI mass spectrometry (MS), electronic absorption (EAs) and vibrational spectroscopy, diffuse reflectance (Ds) and fluorescence (Fs) spectroscopy in condense phases, nuclear-magnetic resonance, ICP, and thermal methods. Quantum chemical DFT calculations, as well as NBO analysis are performed of the novel complexes and ligands. Structurally related model metal–organic chromophores are also studied. The obtained correlation between the theoretical and experimental data marked the studied complexes as promising novel nonlinear optical (NLO) materials.

Morphological and Adsorptive Characteristics of Hydrogen Sulphide on Zinc Oxide Nanoparticles Modified SBA-15

Using microwave-assisted solid-state method, a series of zinc oxide-modified mesoporous SBA-15 materials were synthesized. The desulphurization test with a gas mixture containing 0.1 vol % hydrogen sulfide was carried out on these materials. Chemicals before and after the desulphurization test were analyzed using nitrogen adsorption, XRD, EDS, TEM, ICP and other standard methods. The results suggest that zinc oxide modification can accelerate the transformation from a mesoporous to a zeolite phase. The different zinc loading results in different zinc-phase dispersions on the materials.