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EN
Perovskite catalysts with active phase composed of LaMnO3 or La0.75Ag0.25MnO3 doped with noble metals — platinum or palladium — were tested for activity in oxidation of toluene. Their impregnation with solution of Pt or Pd compounds increased the catalytic activity. LaMnO3 with Pt content displayed the highest activity. LaMnO3 perovskite doped with both noble metals show higher activity than when noble metals were added to La0.75Ag0.25MnO3 perovskite.
EN
The method described in this paper using Dowex Optipore L493 for removal of gold (III), palladium (II), and platinum (IV) ions from hydrochloric solutions is found effective for separation of gold, palladium and platinum. There were carried out laboratory studies of selective removal of platinum (IV), gold (III) and palladium (II) microquantities from 0.1–6 M hydrochloric on the solvent impregnated highly cross-linked styrenic polymer, Dowex Optipore L493 using Cyanex 301. In these experiments the recovery factors % R of gold (III), palladium (II) and platinum (IV) depending on phases contact time were obtained. The gold, palladium and platinum concentrations were determined by the AAS method.
PL
Podano krótko interesujące dane o metalu szlachetnym - platynie.
EN
There are presented, in short, interesting data of the noble metal platinum.
PL
Opisano wydobycie platyny w ośrodkach wydobywczych w świecie oraz jej wykorzystanie w różnych dziedzinach przemysłu w 2002 roku.
EN
The data on the platinum world-wide production volume in 2002 and its application in various industrial sectors have been presented.
EN
The ability of platinum uptake by hydroponically cultivated plants - Indian mustard (Sinapis alba L.) and Anawa maize (Zea mays L.) - was investigated. The efficiency of the transport of platinum compounds from the roots to above ground organs was estimated. For platinum determination in plant samples, digested in closed system with microwave energy, very sensitive analytical methods were applied - adsorptive stripping voltammetry (AdSV) and mass spectrometry with inductively coupled plasma (ICP-MS). For validation of the obtained results the recovery of platinum was examined. The accumulation factors (AF) of platinum: more then 800 and 400 for roots of Indian mustard and Anawa maize, respectively and about 90 and 30 for above ground organs of both species were found.
EN
The results of studies on the separation of platinum(IV) ions by solvent extraction from aqueous solutions after leaching of spent catalysts have been reviewed. The following processes have been discussed: acid leaching of spent catalysts and solvent extraction of platinum(IV) ions by using organophosphorous acids, amines and oximes as the extractants. In hydrometallurgical leaching of spent automobile catalysts many reagents such as aqua regia solutions, aluminum chloride solutions with low concentrations of nitric acid as an oxidant, and sodium cyanide solutions were tested. After leaching, the metal ions in leach solutions have to be separated and purified by solvent extraction. Typical leach liquor contains economically valuable metal ions such as platinum(IV), palladium(II), rhodium(III) nickel(II) and manganese(II). The influence of several factors on the efficiency and selectivity of platinum(IV) ions extraction from leach solutions was shown. The optimum conditions of these processes were also reported on the ground of literature survey.
PL
Wraz ze zwiększającą się ilością samochodów wzrasta zapotrzebowanie na surowce, z których one powstają. O rozwoju motoryzacji może świadczyć ilość samochodów przypadająca na tysiąc mieszkańców. W 2009 r. było to: w Europie – 473, w Japonii – 452, w USA – 437, w Korei Południowej – 270, w Rosji – 235, w Brazylii – 122, w Chinach – 24 i Indiach – 8. Na samym Starym Kontynencie liczba aut jest zróżnicowana. W Luksemburgu przypada 660 aut na tysiąc mieszkańców (statystycznie najwięcej), a w Rumunii, znajdującej się na końcu statystki, 198 aut. W Polsce odnotowano 432 samochodów na tysiąc mieszkańców. Statystki pokazują, że co roku zwiększa się ilość pojazdów poruszających się po drogach świata. Razem ze zwiększającą się ilością aut wzrasta też zapotrzebowanie na surowce, z których powstają nowe pojazdy. Nowe technologie pozwalają na zastosowanie innowacyjnych rozwiązań w procesie projektowania i produkcji aut.
EN
Polyaniline (PANI), an electroactive polymer having amine (-NH-) and imine (-N=) groups in structure is used as the support for platinum and palladium catalysts. They are prepared, characterized by number of techniques (FTIR, XRD, XPS, SEM, TEM) and tested in the hydrogenation of alkyne, 2-butyne-1,4-diol (B3-D), reaction of industrial importance. Catalysts are prepared using aqueous solutions of PdCl2 and H2PtCl6 of pH = 2-3. In these conditions redox mechanism is involved resulting in partial reduction of Pd2+ to Pd0 and Pt4+ to Pt2+. In the as-prepared 2%Pd/PANI and additionally reduced 2%Pt/PANI catalysts the particles of Pd, Pt metal of size in nano-scale are formed. Performance of Pt and Pd-doped PANI in the hydrogenation of 2-butyne-1,4-diol (B3-D) strongly varies. In particular they differinability for selective hydrogenation of unsaturated C Identical to C bond in B3-D to 2-butene-1,4-diol. Catalytic performance of 2%Pt/PANI is found to be similar to that observed for typical, in organic carrier supported platinum catalysts. 2%Pd/PANI catalyst of fers much higher activity and almost se lectively reduces C Identical to C bond in B3-D to C Identical to C in B2-D. This advantageous performance of Pd/PANI catalyst can be related to an influence of electroactive matrix on properties of palladium centres.
EN
Human promyelocytic leukemia cells,. HL-60, were treated with cisplattn [cis-diamminedichloroplatinum (II)] (2 itiM, 1 h). DNA- eisplatin-protein complexes were isolated and exposed to thiourea (1M), NaCN (100 mM), diethyldithio-carbamate (500 mM), or tf-methyl-D- glucamine dithiocarbamate (500 mM) for 12 h. The release of platinum was measured by atomic absorption spectroscopy. Sodium cyanide was the most effective agent, releasing about 90% of the DNA-bound platinum. Thiourea was the least effective agent, while dithiocar- bamates exhibited an intermediate. The ability of the same group of agents to split the proteins off from the protein-cisplatin-DNA complex was also evaluated and similarly dithiocarbamate were also the most effective.
EN
This review classifies and analyzes over thirty heterooligonuclear platinum clusters with a wide variety of metal frameworks, from twelve to forty-four. There are thirteen heterometals (Ge, Sn, Hg, W, Mo, Ru, Rh, Pd, Os, Ni, Cu, Ag, Au) which are the partners of platinum. The clusters mostly crystallize in monoclinic (36,4%) and triclinic (30,3%) crystal classes. Their structures are complex, with platinum most commonly preferring interstitial sites, such as the centroids of icosahedrons. There are examples of distortion isomerism. The most common ligands are CO and PPh3, and it is interesting that the mean Pt-CO and M-CO bond distances are identical at 1.84 Å. In contrast, the mean Pt-μCO and M-μCO are of values of 2.02 and 1.97 Å, respectively, while the Pt-PPh3 and M-PPh3 bond distances are 2.30 and 2.28 Å, respectively. The shortest Pt-Pt, Pt-M (non-transition) and Pt-M (transition) bond distances are 2.559(2) Å, 2.412(2) Å (M = Ge) and 2.510(2) Å (M = Ni).
EN
This review classifies and analyzes over fifty heterohepta- and heterooctanuclear platinum clusters. There are eight types of metal combinations in heteroheptanuclear: Pt6M, Pt5M2, Pt4M3, Pt3M4, Pt2M5, PtM6, Pt3Hg2Ru2 and Pt2Os3Fe2. The seven metal atoms are in a wide variety of arrangements, with the most common being one in which the central M atom (mostly M(I)) is sandwiched by two M3 triangles. Another arrangement often found is an octahedron of M6 atoms asymmetrically capped by an M atom. The shortest Pt-M bond distances (non-transition and transition) are 2.326(1) Å (M = Ga) and 2.537(6) Å (M = Fe). The shortest Pt-Pt bond distance is 2.576(2) Å. In heterooctanuclear platinum clusters there are eight types of metal combinations: Pt6M2, Pt4M4, Pt3Ru5, Pt2M6, PtM7, Pt2W4Ni2, PtAu6Hg and PtAu5Hg2. From a structural point of view, the clusters are complex with bicapped octahedrons of eight metal atoms prevailing. The shortest Pt-M bond distances (non-transition and transition) are 2.651(3) Å (M = Hg) and 2.624(1) Å (M = Os). The shortest Pt-Pt bond distance is 2.622(1) Å. These values are somewhat longer than those in the heteroheptanuclear clusters. Several relationships between the structural parameters were found, and are discussed and compared with the smaller heterometallic platinum clusters
EN
This review covers heteropolynuclear platinum complexes. There are over sixty examples with heterometal atoms as partners including non- transition metals, K, Cs, Mg, Ca, Sr, Tl, Sn, Pb, Zn, Cd, and transition metals: Cu, Ag, Fe, Co, Ni, Rh and Pd. In addition, there are examples for the lanthanides, Eu and Yb. The most common are Ag (x16) and K (x14). The predominant geometries for Pt(II) is square-planar and for Pt(IV) is octahedral. The overall structures are complex. In spite of the wide variety of heterometal atoms partners of platinum, there is “real” Pt-M bonds only with silver, ranging from 2.678 to 2.943(I) Å (ave 2.855 Å). The mean Pt-Pt bond distance is 2.869 Å.
EN
This review classifies and analyses fifty heteronona- and heterodecanuclear Pt clusters of metal composition: Pt4Ru5, Pt3Ru6, Pt20sr PtRh8, PtAu8; Pt6M4, Pt5M5, Pt4M6, Pt3M2, Pt2M8, PtM9, Pt3Ru6M and PtAu8M. There are nine different heterometals: M = Ru, Au, Ag, Cu, Hg, Os, Rh, Ir and Fe, of which Ru and Au are the most frequent. The clusters crystallize mostly into two crystal classes, monoclinic (74%) and triclinic (18%), and their structures are complex. Three triangular layers of nine metal atoms arranged in the form of a face-shared bioctahedron are common in the series of heterononanuclear clusters. In the series of heterodecanuclear clusters distorted skeletal icosahedrons, where a central platinum atom is surrounded by nine metal atoms, and face (edge) shared (fused) bioctahedral cluster of the metal atoms are the most common. The most frequent ligands are CO and PPh3. The shortest metal-metal bond distances are: 2.540(4) Å (Pt-Fe), 2.580(2) Å (Ru-Ru), 2.584 Å (Pt-Pt) and 2.629(4) Å (Cu-Au). Several relationships between the structural parameters were found and are discussed. Some clusters contain two crystallographically independent molecules within the same crystal and are examples of distortion isomerism.
EN
For several decades an increase of platinum in the environment was recorded. This is connected with the release of platinum from automobile catalytic converters and pharmaceutical industries. In the conducted experiments the effect of various forms and concentrations of platinum on the germination and roots growth of different plants (oat, garden cress and tomato) was investigated. Two separate experiments were performed with lower (experiment 1st: 1, 5 and 10 mg/L) and higher (experiment 2nd: 10, 20 and 40 mg/L) [Pt(NH3)4](NO3)2 or PtCl4 dosages. There was no significant effect of dose and form of platinum on the germination of seeds (experiment 1st and 2nd). The effect of platinum containing substances dose on root growth of young seedlings was observed during experiment, dependent on the species of tested plants. The root length of oat plants was similar in all treatments in experiment 1st. The shortest tomato roots were observed in the case of a 10 mg/L of PtCl4, it was statistically shorter than the control plants (treated with water) as well. The roots of the tomato treated with [Pt(NH3)4](NO3)2 were the same length as observed for the control sample. The garden cress root growth was not affected by [Pt(NH3)4](NO3)2, but a solution containing Pt4+ stimulated the root growth. The roots of tomato and oat treated with [Pt(NH3)4](NO3)2 had similar length as the control plants in contrast to the far shorter roots treated with PtCl4 (experiment 2nd). Moreover, the treatment with [Pt(NH3)4](NO3)2 stimulated the growth of garden cress roots compared to the control, while only the lowest dose of PtCl4 stimulated the root growth.
EN
Although Ag-Pt system is crucial for several technological applications, investigations of the thermodynamic properties of this system are limited. In the present study, activity of silver at various temperatures in the platinum rich solid solution was measured by a solid electrochemical method and employing AgI as the solid electrolyte. The EMF was determined using a galvanic cell (–)|Ag|AgI|Ag – Pt alloy|C|Pt (+), which provided novel experimental data on thermodynamic properties of a Ag-Pt alloy. Activity, partial molar of Gibbs energy, enthalpy and entropy of silver in a solid solution containing 1 at % Ag between 573 and 673 K have been calculated. The results indicated that the activity of silver obtained in the present study shows a large positive deviation from the ideal Raoultian behavior. Microstructures of alloys with different compositions were also compared.
EN
Stabilized landfill leachate contains high fractions of refractory organics that cannot be effectively degraded by simple biological or physicochemical treatment. Thus, primary treatment was required to improve biodegradability and enhance treatment efficiency. This study investigated the role of Boron-Doped Diamond (BDD) and platinum (Pt) anodes at a current density of 29.2 and 33.3 mA/cm2 in the electrochemical processes for the pretreatment of stabilized leachate. A three-compartment electrochemical reactor was used in the research to enhance the removal of ionic pollutants. The pollutants were measured as total dissolved solids (TDS), chemical oxygen demand (COD), ammonium-nitrogen (NH4–N), and nitrite (NO2–). The reactor performance was then analyzed using a regular two-level factorial design. The results showed that the electrochemical process effectively removed organic and inorganic pollutants. The highest removal was obtained at 33.3 mA/cm2 using the BDD, measured around 48, 82, 60, and 79% for TDS, COD, NH4–N, and NO2–, respectively. Meanwhile, the specific energy consumption for COD removal was estimated to reach 1.5 and 1.55 Wh/g for BDD and Pt, respectively. These results imply that the type of anodes and applied current densities significantly influence the treatment efficiency.
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88%
EN
The ability of hydroponically cultivated Indian mustard plants (Sinapis alba L.) to accumulate platinum was investigated. The Pt-bioaccumulation in leaves, stem and shoots of plants growing for 2 and 4 weeks at Pt-concentration of 50 and 500 ěg/L was compared. The relation between dry and fresh weight was also estimated. Adsorptive stripping voltammetry (AdSV) and mass spectrometry with inductively coupled plasma (ICP-MS) were applied for determination of Pt. Increasing Pt-concentration from 50 to 500 ěg/L in the medium causes: (1) reduction of the root tissue hydration level at unchanged modification in aboveground parts of the plants and (2) decrease of the Pt transfer factor (TF) for roots and increase for leaves and stem. Duration of the culture influenced on Pt-accumulation in roots and in aboveground organs of mustard plants. Transfer factor for Pt between 560 and 1600 makes Indian mustard plants one at Pt-hyperaccumulators. Distribution of Pt-bioaccumulation in the plant organs may be useful for biomonitoring of platinum in the environment.
EN
In this paper, the kinetics of the platinum(IV) chloride complex ions reduction reaction was studied. It was shown that the mechanism exhibits autocatalytic character. The presence of metallic platinum in the system significantly increases the reaction rate. The influence of the initial concentration of precursor, reductant, ionic strength, initial concentration of the chloride ions as well as the temperature on the process rate was investigated. The activation energy was determined and is equal to 93.57 kJ/mol. Moreover, the obtained metallic phase was analyzed, and it was observed that it has a micrometric size.
EN
In this paper, sensitivity enhancement of a nanocomposite-based optical fiber sensor with platinum nanoparticles is investigated. This optical fiber sensor is based on the surface plasmon resonance in the nanocomposite layer coating the core of optical fiber. A comparison is carried out for sensitivity between an optical fiber sensor based surface plasmon resonance with platinum layer and the one with nanocomposite layer. The nanocomposite layer consists of platinum nanoparticles with varying volume fraction which is arrayed in a host dielectric material of InN or TiO2. We show that the sensitivity of the sensor with a nanocomposite layer containing platinum nanoparticles is bigger than the sensitivity of the sensor with a platinum layer for all the values of refractive index of sample media. Also, the effect of the thickness of the nanocomposite layer and the volume fraction of platinum nanoparticles on the spectrum of the transmitted power has been investigated.
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