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1

Wpływ temperatury i stężenia wodoru na aktywność i selektywność wybranych katalizatorów heterogenicznych zawierających metale szlachetne w procesie uwodornienia metyloacetylenu i propadienu

Kacprzak Krzysztof, Lewera Adam

Przemysł Chemiczny

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2023

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T. 102, nr 7

700--706

PL

Katalizatory Pd/Al₂O₃, Pd/TiO₂ i Pt/Al₂O₃ otrzymano metodą impregnacji-redukcji i zastosowano do zbadania wpływu nadmiaru wodoru i temperatury prowadzenia procesu na selektywność i aktywność w procesie selektywnego uwodornienia metyloacetylenu i propadienu zawartych we frakcji węglowodorów C₃ z krakingu parowego. Katalizatory zawierające pallad wykazywały wyższą aktywność i selektywność niż Pt/Al₂O₃, ale w obecności nadmiaru wodoru w większym stopniu następował spadek ich selektywności. W niskich temperaturach, w obecności katalizatora Pd/TiO₂ obserwowano większy przyrost propylenu i większe stężenie pozostałego metyloacetylenu i propadienu, a w warunkach zwiększonego stężenia wodoru i w umiarkowanych temperaturach charakteryzował się on wyższą aktywnością (i niewielkim spadkiem selektywności), co czyni z niego interesującą alternatywę dla powszechnie stosowanych w tym procesie katalizatorów Pd/Al₂O₃.

EN

The Pd/Al₂O₃, Pd/TiO₂ and Pt/Al₂O₃ catalysts obtained by the impregnation-redn. method were used for selective hydrogenation of MeC≡CH and CH₂=C=CH₂ (contained in the C₃ fraction stream from the steam cracking process) to MeCH=CH₂. Pd-contg. catalysts showed higher activity and selectivity than Pt/Al₂O₃, but the excess of H₂ caused a decrease in their selectivity to a greater extent. In the presence of Pd/TiO₂, a greater increase in the MeCH=CH₂ content was obsd. than in Pd/Al₂O₃ at low temps., but at the same time higher concns. of residual MeC≡CH and CH₂=C=CH₂ were obsd. Under conditions of increased H₂ concn. and moderate temps., the Pd/TiO₂ catalyst showed higher activity (and a slight decrease in selectivity), which makes it an interesting alternative to the Pd/Al₂O₃ catalysts commonly used in the process.

2

The Role of Boron-Doped Diamond and Platinum Anodes in the Three-Compartment Electrochemical Pretreatment of Stabilized Landfill Leachate – Response Surface Methodological Approach

Bagastyo Arseto Yekti, Anggrainy Anita Dwi, Rosyidah Badriyah

Journal of Ecological Engineering

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2022

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Vol. 23, nr 12

50--60

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.

3

The importance of recovery of PGMS from catalysts - a case study of recycling network in Poland

Generowicz Natalia

Architecture Civil Engineering Environment

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2022

|

Vol. 15, no. 2

149--156

EN

Combustion engines are the main driving force of passenger cars, trucks or buses. Engines burn fuels, and as a side effect, release many pollutions to the atmosphere. Car manufacturers had been aware of a need of lowering the amount of exhaust fumes. This brought on the market the first catalytic converters. Nowadays automobile catalyst manufacturing is the largest sector of demand of PGMs (mainly platinum, palladium and rhodium), and unfortunately consumption and future demand of there critical metals is getting higher. Over the past two decades, most countries around the world have developed and implement solutions that would minimize the impact of the growing number of cars on the environment. One solution contributing to this is the organisation of an end-of-life car collection and recycling network, which is now an integral part of automotive industry. The main drivers for the development of such network were stricter environmental regulations and economic conditions. The development of recycling is also becoming more popular in Poland. However, catalyst recycling system is still not transparent to all stakeholders. Due to the huge variety of catalysts and their different structure and composition of elements from the PGMs group, the valuation of their price before they are recycled is not obvious. This raises a lot of controversy and does not inspire trust among those who recycle their catalysts. The aim of this work is to show how the management of used catalytic converters looks like in Poland and how developed is network of catalysts recycling in Poland. At the same time this will show how important it is in terms of a circular economy and the recovery of valuable raw materials from a group of PGMs.

4

Kinetic Studies of Pt(IV) Chloride Complex Ions Reduction Reaction Using Potassium Formate

Wojnicki M., Żabiński P., Csapó Edit

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 3

1135--1140

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.

5

Sensitivity enhancement of a nanocomposite-based fiber optics sensor with platinum nanoparticles

Vahed Hamid, Ghazanfari Elham

Optica Applicata

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2019

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Vol. 49, nr 1

65--74

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.

6

Założenia do utworzenia sieci odzysku platynowców ze zużytych katalizatorów samochodowych w Polsce

Święcicka Zofia, Saternus Mariola, Gajdzik Bożena

Gospodarka Materiałowa i Logistyka

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2019

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nr 3

22--32

PL

Rosnące ceny wydobycia metali szlachetnych oraz zmiany przepisów recyklingowych w państwach Unii Europejskiej skutkują wymogiem odzysku platynowców ze zużytych katalizatorów samochodowych. W Polsce przerób zużytych katalizatorów na skalę produkcyjną właściwie nie istnieje, ponieważ tylko nieliczne przedsiębiorstwa zajmują się przerobem platyny jako surowca wtórnego. Proces odzysku platynowców (Pt, Pd i Rh) z katalizatorów pochodzących z recyklingowych części samochodowych na rynku krajowym realizowany jest zagranicą. Wiedza na temat sposobu organizacji sieci odzysku platynowców w trakcie demontażu samochodów w Polsce jest ważnym elementem stworzenia uzupełniającego źródła produkcji platyny na rynku krajowym. W niniejszej pracy przedstawiono konfiguracje możliwej struktury sieci podmiotów współpracujących ze sobą w procesie odzyskiwania platyny ze zużytych katalizatorów samochodowych.

EN

Increasing prices of precious metals extraction and changes in recycling regulations in European Union Member States result in the requirement of Platinum recovery from used car catalysts. In Poland, there is practically no processing of used car catalysts on a production scale, as only a few companies deal with the processing of platinum as a secondary raw material. The process of platinum group metals recovery (Pt, Pd and Rh) from catalytic converters from car recycling on the domestic market is carried out abroad. Knowledge about the organization of the platinum recovery network during the dismantling of cars in Poland is an important element in creating a complementary source of Platinum production on the domestic market. This paper presents configurations of a possible network structure of entities cooperating with each other in the process of Platinum recovery from used car catalysts.

7

The Influence of Steric Stabilization on Process of Au, Pt Nanoparticles Formation

Luty-Błocho M.

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 1

55--63

EN

Nanoparticles are very fascinating area of science not only due to their unique properties but also possibility of producing new more complex materials, which may find an application in modern chemistry, engineering and medicine. In process of nanoparticles formation very important aspect is a rate of individual stage i.e. reduction, nucleation and autocatalytic growth, because this knowledge allows for proper materials design, morphology manipulation, stability. The last one aspect can be realized using proper electrostatic, steric and electrosteric stabilization. However until now nobody reports and measures kinetic rates of all stages during process of particles formation in the presence of steric stabilizers. Thus, the main contribution of this paper is determination of individual rate constants for nanoparticles formation in the presence of steric stabilizers and their comparison to the system without stabilizer. For this purpose, an aqueous solution of Au(III) and Pt(IV) ions were mixed with steric stabilizers like PVA and PVP, and reduced using L-ascorbic acid as a mild and sodium borohydride as a strong reductant. As a results stable nanoparticles were formed and process of their formation was registered spectrophotometrically. From obtained kinetic curves the values of observed rate constants for reduction metal ions, slow nucleation and fast autocatalytic growth were determined using Watzky-Finke model. It was found that the addition of polymer affects the rate of the individual stages. The addition of steric stabilizers to gold ions reduced with L-ascorbic acid causes that the process of nucleation and autocatalytic growth slows down and the value of observed rate constants for nucleation changes from 3.79·10-3 (without polymer) to 7.15·10-5 s-1 (with PVA) and for growth changes from 1.15·103 (without polymer) to 0.48·102 s-1 M-1 (with PVA). However, the rate of the reduction reaction of Au(III) ions is practically unchanged. In case of using strong reductant the addition of polymer effects on the shape of kinetic curve for reduction of Au(III) and it suggests that mechanism is changed. In case of Pt(IV) ions reduction with L-ascorbic acid, the process speeds up a little when PVA was added. Determined values of observed rate constants for nucleation and growth platinum nanoparticles decrease twice comparing to the system without polymer. The reduction of Pt(IV) ions with sodium borohydride accelerates when PVP was added and slows down when PVA was used. Moreover, the size of obtained colloidal gold and platinum was also analysed using DLS method. Obtained results (rate constants) may be useful in the process of nanomaterials synthesis, in particular in microflow.

8

Badanie transportu jonów metali w wybranych układach separacyjnych

Rzelewska-Piekut M., Janiszewska M., Staszak K., Regel-Rosocka M.

Przemysł Chemiczny

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2018

|

T. 97, nr 12

2045--2049

PL

Przedstawiono ługowanie, ekstrakcję ciecz-ciecz i ultrafiltrację micelarną jako skuteczne sposoby wydzielania takich pożądanych jonów metali, jak platynowce i kobalt z odpadowych katalizatorów samochodowych i z roztworów wodnych.

EN

Pulverized spent automobile catalyst was leached with acidic solns. (optionally with H₂O₂). The leachates were liq.-liq. extd. with com. org. phase-contg. complexants to remove Fe(III), Mg(II) and Zn(II) ions and to sep. them from Pt group ions present in the raffinate. Co(II) ions were also recovered by using a com. complexant. The ultrafiltration in presence of surface active agents resulted in sepn. of Co(II) ions from Zn(II) ions.

9

Estimation of the chemical specific surface area of catalytic nanoparticles by TEM images analysis

Pawlyta M., Sobel B., Liszka B.

Journal of Achievements in Materials and Manufacturing Engineering

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2018

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Vol. 87, nr 1

5--12

EN

Purpose: The purpose of this article is the development of quantitative methods for assessing the quality of nanocomposite materials used in fuel cells. Design/methodology/approach: latinum is the most commonly used catalyst in fuel cells, commonly in the form of nanoparticles deposited on the surface of carbon black. Due to the nanometric size of platinum particles, transmission electron microscopy can be applied to evaluate the produced catalysts. TEM image also allow to determinate the approximate value of the chemical specific surface area) of platinum nanoparticles, but only in case of spherical particles. Findings: In present work, taking into account additional assumptions resulting directly from the analysis of microscopic images, the method of estimation of the particle diameter and the chemical specific surface area for nonsymmetrical (elongated) nanoparticles is present. Research limitations/implications: The presented work presents a method for determining the specific surface of platinum, when their shape is elongated. It is worth noting that the modified formulas for determining the particle diameter and the value of the chemically active specific surface of the platinum nanoparticles of the elongated shape are equivalent to the formulas previously given for spherical particles, if the particle length and its diameter are equal. In this case, patterns for symmetric particles and more general (modified) patterns can be used interchangeably. Practical implications: Development of new and more effective catalysts for fuel cells. Originality/value: The significance of the presented work results from the possibility of using the described method in the catalyst studies during real catalytic processes. It allows comparing catalytic activity after the process, also in unusual conditions and in an aggressive environment, using minimal amounts of material.

10

Thermodynamic Properties of Ag-Pt Alloy Measured Using a Solid Electrochemical Method

Santoso I., Taskinen P.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 1

191--197

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.

11

Occurrence of platinum group metals in the environment and their use

Trębacz H., Michno P.

Structure and Environment

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2017

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Vol. 9, no. 4

283--298

EN

Monoliths that are part of the automotive catalysts include noble metals: platinum, palladium and rhodium, which acts as a catalyst. During the operation of these devices platinum group elements (PGE) are released into the environment. The characteristics of individual metals belonging to the platinum group are presented in this article. These metals can be found in road sediments as well as in water or food. Platinum resources are constantly shrinking, so one of the ideas is their exploitation from the solar system. This article also presents methods of platinum recovery. The publication provides an overview of the literature on platinum-related issues.

PL

Monolity, które są częścią katalizatorów samochodowych, zawierają metale szlachetne: platynę, pallad i rod, które pełnią funkcję katalityczne. W trakcie eksploatacji tych urządzeń następuje emisja platynowców do środowiska. Przedstawiono charakterystykę poszczególnych platynowców. Metale te możemy odnaleźć w osadach drogowych, jak i w wodzie czy żywności. Zasoby platynowców stale się kurczą, dlatego jednym z pomysłów jest ich eksploatacja z Układu Słonecznego. Zaprezentowano również metody odzysku platynowców. W publikacji przedstawiono przegląd literatury dotyczącej zagadnień związanej z platynowcami.

12

Wpływ wilgotności na odpowiedź rezystancyjnego czujnika chloru domieszkowanego platyną

Fiedot M., Rac-Rumijowska O., Suchorska-Woźniak P., Stafiniak A., Teterycz H.

Przegląd Elektrotechniczny

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2017

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R. 93, nr 8

110--113

PL

W artykule przedstawiono właściwości rezystancyjnego czujnika gazowego chloru z warstwą aktywną wykonaną z tlenku cynku domieszkowanego platyną. Materiał gazoczuły syntezowano metodą hydrotermalną (CBD). Badania za pomocą skangowego mikroskopu elektronowego (SEM) oraz metodą dyfrakcji rentgenowskiej (XRD) wykazały, że otrzymano mikropręty tlenku cynku domieszkowane metaliczną platyną. Analizę właściwości sensorowych przeprowadzono w obecności 2 ppm Cl2 w atmosferze o różnej wilgotności. Uzyskane wyniki wykazały, że konduktancja warstwy gazoczułej maleje w obecności gazowego chloru a jej wartość zależy od wilgotoności badanej atmosfery. W atmosferze o wilgotności względnej 75% czułość sensora jest na podobnym poziomie jak w powietrzu o wilgotności 30% RH, natomiast w 90% RH znacznie maleje.

EN

This article shows the resistive chlorine sensor with active layer made of zinc oxide doped with platinum. The sensing material was synthesized by hydrothermal methode (CBD). Scanning electron microscope (SEM) and X-ray diffraction (XRD) showed that zinc oxide microrods doped with platinum were obtained. Sensing analysis was performed in the presence of 2 ppm of Cl2 in atmospheres of varying humidity. The obtained results have shown that the conductivity of the active layer decreases in the presence of chlorine and its value depends on the moisture content of the tested atmosphere. At 75% RH the system sensitivity is similar to 30% RH, while 90% RH is significantly reduced.

13

Kinetics of the reaction of platinum (IV) chloride complex Ions in aqueous solution, in the presence of C2H5OH

Pacławski K., Karczewski K.

Rudy i Metale Nieżelazne Recykling

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2016

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R. 61, nr 8

337--343

EN

In this work, the kinetic studies of the reaction of platinum (IV) chloride complexes ([PtCl6 ] 2-) with ethyl alcohol in aqueous solution were carried out. Obtained data suggest the complex character of the reaction which is sensitive to pH of the solution. It was found that in the alkaline solution two parallel reaction paths are present: hydrolysis and the redox reaction of [PtCl6 ] 2-. It leads to [PtCl5 (H2O)] - and [PtCl4 ] 2- ions formation in the system. Both reactions has bimolecular character and at 55oC and at pH =12, are described by the second-order rate constants: k1 = 0.085.10 -3 [M -1s -1] (for the hydrolysis) and k2 = 3.55.10 -3 [M -1s -1] (for the redox reaction). Experimentally determined values of enthalpy and entropy of activation for the hydrolysis reaction are equal to 23.654 [kJ mol -1] and -187.16 [J mol -1 K -1], respectively. The same parameters for the redox reaction are as follows: 24.016 [kJ mol -1] and -166.591 [J mol -1 K -1], respectively. As a result of data analysis it was also suggested that the ethyl alcohol may play a catalytic role during [PtCl6 ] 2- hydrolysis. Its presence leads to slight acceleration of this reaction and to slow Pt 4+ reduction.

PL

W pracy przedstawiono wyniki badań kinetycznych reakcji kompleksów chlorkowych platyny (IV) ([PKI6]2') z alkoholem ety/owym, w roztworach wodnych. Otrzymane dane sugerują złożony charakter reakcji, czuły na pH roztworu. Wykazano, że w roztworach alkalicznych obecne sq dwie rów¬noległe ścieżki reakcji: hydroliza i reakcja redoks [PtCI6]2'. Prowadzi to do utworzenia jonów [PtCI5(H20)]~ i[PtCIJ2' w układzie. Obydwie reakcją mają charakter dwucząsteczkowy i w temperaturze 55°Coraz przy pH= 12 sq opisane przez drugorzędowe stałe szybkości reakcji: kt = 0,085.10'3 [M'1 s'1] (dla hydrolizy) ik2 - 3,55.10~3 [M~1s~1] (dla reakcji redoks). Wyznaczone doświadczalnie wartości entalpii i entropii aktywacji dla reakcji hydrolizy są odpowiednio równe 23,89 [kj-mol1] i -152,9 [l-mol''-K'']. Te same parametry dla reakcji redoks wynoszą: 24,016 [kj-mol~'] i -166,6 [l-mol^-K1]. lako wynik analiz danych doświadczalnych sugeruje się również, że alkohol etylowy pełni rolę katalizatora w czasie hydrolizy [PtCIJ2'. lego obecność prowadzi do nieznacznego przyspieszenia tej reakcji oraz do powolnej redukcji Pt4+.

14

MWCNT-Pt nanocomposite as the active element of harmful gas sensors

Dobrzańska-Danikiewicz A. D., Łukowiec D., Wolany W., Procek M., Sękala A.

Archives of Materials Science and Engineering

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2016

|

Vol. 81, nr 1

14--21

EN

Purpose: The goal of this paper is presentation of the variations in MWCNTs-Pt nanocomposite resistance which were examined in the presence of hydrogen with a rising concentration of, respectively, 1, 2, 3 and 4% H2 as well as nitrogen dioxide with a rising concentration of, respectively, 20, 100, 200, 400 ppm of NO2. Design/methodology/approach: Variations in electrical conductivity for the MWCNTs-Pt composite placed, alternately, in the atmosphere of gas and in the atmosphere of selected gases, were measured with a measuring station equipped with precision and inert gas reducers, mass flow meters, filtration systems of gas mixture and the studied mixture’s humidity and temperature control. An active layer of the transducer consisted of MWCNTsPt nanocomposite deposited thereon. All the measurements were carried out in the atmosphere of synthetic air (20% of O2 and 80% of N2) at 22.5°C. Findings: It was found based on the results obtained that system resistance is rising as hydrogen concentration is rising in the atmospheric air. The results of analogous examinations of variations in MWCNTs-Pt nanocomposite resistance carried out for a varying concentration of nitrogen dioxide in the atmosphere of synthetic air are opposite, because lowering system resistance was noted along with a heightening concentration of NO2. The best results were achieved for the nanocomposite presented in the article having a 5% mass concentration of platinum and with uniformly dispersed Pt particles on the surface of carbon nanoparticles. Practical implications: The outcomes presented signify the selectiveness of the applied system consisting of carbon nanotubes decorated with platinum nanoparticles. It means that this material can be used as the active element of harmful gas sensors. Originality/value: A carbon-metal MWCNTs-Pt nanocomposite with special electrical properties was fabricated in the course of research works, whose originality is based on the appropriately selected composition and the specific morphology.

15

Woltamperometryczna metoda oznaczania platynowców na stałej elektrodzie bizmutowej

Hołowiak D., Baś B., Węgiel K.

Analit

|

2016

|

Nr 2

164--169

PL

W pracy zaprezentowano nowatorski opis woltamperometrycznej procedury oznaczania jednego z metali z grupy platynowców, Pd(II), przy użyciu pierścieniowej elektrody bizmutowej (RBiABE) z elektrochemicznie aktywowaną powierzchnią. Praca dotyczy niezwykle istotnych zagadnień związanych z oznaczaniem śladowych ilości platynowców w próbkach środowiskowych. Badanie przeprowadzono przy wykorzystaniu katalityczno-adsorpcyjnej woltamperometrii stripingowej CAdSV. W opracowaniu zawarto niezbędne informacje o źródłach zanieczyszczenia środowiska związkami palladu i platyny, a także opisano inne metody analityczne stosowane do oznaczania śladowych zawartości Pd(II) i Pt(II). Analiza obejmowała oznaczenie jonów Pd(II) w dotowanych próbkach wód (z rzeki Rudawa oraz wody wodociągowej), dokładność metody potwierdzono przez badanie odzysku. Uwagę skupiono na doborze najkorzystniejszych parametrów instrumentalnych rejestracji woltamogramów oraz optymalizacji składu elektrolitu podstawowego. W optymalnych warunkach pomiaru, dla proponowanej procedury oznaczania Pd(II) uzyskano limit detekcji LoD = 3·10-3 μg/L, liniową odpowiedź w zakresie 2–180 μg/L i powtarzalność w granicach od 0,1 do 7,7%. W celu oceny zakresu liniowości metody sporządzono krzywą kalibracji, dla której uzyskano współczynnik korelacji r = 0,9997. Stwierdzono, iż przedłożona procedura analityczna pozwala na precyzyjne i dokładne oznaczenie jonów Pd(II) w próbkach wód rzecznych. Stąd wniosek, że metoda może znaleźć zastosowanie w rutynowych oznaczeniach jonów palladu w wodach.

EN

This work describes application a novel type of renewable bismuth bulk annular band working electrode (RBiABE) for adsorptive stripping voltammetric (AdSV) determination ions of platinum group metals - Pd (II). Measurements were performed using catalytic-adsorptive stripping voltammetry (CAdSV). The usefulness of the electrode RBiABE in environmental analysis was demonstrated by studying the recovery of Pd(II) from spiked tap and river water samples (Rudawa - Kraków, Poland). Considerable attention is focused on the selection of instrumental parameters (composition of the electrolyte, pH, time and potential). The proposed method was successfully applied in determination of the ion Pd (II), the limit of detection was LoD = 3 · 10-3 mg / L, a linear response in the range of 2-180 mg / L and repeatability in the range of 0.1 to 7.7% . The effectiveness of the procedure was tested by studying the linearity of the method (r = 0.9997). The analytical procedure allows for precise and accurate determination of Pd (II) ions in the samples of river water. Therefore, it can successfully be used in routine assays of palladium ions in water samples.

16

Various forms of platinum deposited on carbon nanotubes

Dobrzańska-Danikiewicz A. D., Wolany W., Łukowiec D., Cichocki D., Burda M.

Archives of Materials Science and Engineering

|

2015

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Vol. 75, nr 2

53--62

EN

Purpose: The main purpose of the article is to present interesting forms of platinum at a nanometric scale. There are multiple fabrication methods of nanoparticles, nanowires and other forms of platinum, and the methods proposed in the article are simple and effective. They employ carbon nanotubes in the form of a so-called forest, manufactured by CVD methods and nanotubes dispergated (in a water or ethylene glycol solution) as templates for deposition of Pt nanoforms. Design/methodology/approach: Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were applied for showing the structure and morphology of platinum nanoforms deposited on carbon nanotubes, and Energy Dispersive Spectroscopy (EDS) was used for confirming the chemical composition of the analysed structures. Findings: The microscope examinations carried out with scanning electron microscopy have shown that platinum may crystallise by assuming the form of, notably, nanoparticles, nanowires and nanocubes. The structure of carbon nanotubes covered with nanoparticles of Pt at a nanoscale could have been observed by applying high-resolution transmission electron microscopy. Practical implications: Carbon nanotubes decorated with Pt nanoparticles and platinum at a nanometric scale are used as, in particular, an active layer of chemical and biochemical sensors. In addition, excellent catalytic properties of platinum are used in various industrial processes, including chemical, automotive and petroleum industry. Originality/value: Chloroplatinic acid H2PtCl6 is an input substance for producing various forms of platinum. Platinum exhibits unique physiochemical properties at a nanoscale, different than its properties at a macro scale. It was confirmed that the selected fabrication method of platinum nanoforms is effective and simple.

17

Influence of platinum ions on the germination and seedling root growth of different plant species

Kołton A., Czaja M.

Geology, Geophysics and Environment

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2014

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Vol. 40, no. 4

343--348

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.

18

Preliminary Studies on Simultaneous Recovery of Precious Metals from Different Waste Materials by Pyrometallurgical Method

Willner J., Fornalczyk A., Cebulski J., Janiszewski K.

Archives of Metallurgy and Materials

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2014

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Vol. 59, iss. 2

801--804

EN

Automotive catalytic converters have a limited life time, after which the catalyst must be replaced or regenerated. The spent catalytic converters contain small amount of precious metals. Recovery of these metals is essential for environmental and economic reasons. The waste electronic equipment is also an attractive source for recovery of precious metals. Precious metals in electronic scraps are concentrated mainly in printed circuits and integrated circuits - so generally in elements that are the most diverse in their composition. Material heterogeneity of these elements is the reason why there is no universal method for processing this type of scrap. Methods used in the world for recovery of precious metals from spent auto catalytic coverters and electronic wastes by pyrometallurgical and hydrometallurgical methods were mentioned in this paper. The results of simultaneous melting of electronic waste with spent automotive catalysts were presented. The printed circuit boards were used as the carrier and as a source of copper. The precious metals present in the catalyst were collected in copper.

PL

Samochodowe konwertory katalityczne mają ograniczony czas życia, po czym katalizator ten należy wymienić lub poddać regeneracji. Zużyte katalizatory zawierają niewielkie ilości metali szlachetnych, a możliwość odzysku tych metali jest istotna ze względów ekonomicznych i ekologicznych. Równie atrakcyjne źródło metali szlachetnych stanowi wycofany sprzęt elektroniczny. Metale szlachetne w płytkach elektronicznych są zlokalizowane głównie w obwodach drukowanych układów scalonych, które są najbardziej zróżnicowane pod względem składu. Niejednorodność materiałowa tych elementów powoduje, że nie ma uniwersalnego sposobu przetwarzania tego rodzaju złomu. W artykule zwrócono uwagę na metody pirometalurgiczne i hydrometalurgiczne stosowane na świecie do odzysku metali szlachetnych ze zużytych katalizatorów samochodowych oraz od- padów elektronicznych. Przedstawiono wyniki badań próby wspólnego przetopu odpadów elektronicznych z odpadami zużytych katalizatorów samochodowych. Odpady elektroniczne w postaci drukowanych płytek obwodowych zostały wykorzystane jako nośnik i główne źródło miedzi, metalu pełniącego rolę metalu zbieracza platynowców, obecnych w katalizatorach. Otrzymano stop Cu-Fe-Au-Pt odzyskując w ten sposób platynę na poziomie około 78%.

19

Features of platinum as the carbon nanocomposites component

Dobrzańska-Danikiewicz A. D., Łukowiec D.

Archives of Materials Science and Engineering

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2014

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Vol. 66, nr 2

53--61

EN

Purpose: The primary aim of the article is to present the methodology of selection of a noble metal for a constituent component of a Carbon NanoTubes-NanoParticles (CNT-NPs) nanocomposite. The platinum group elements, i.e. Pt, Rh, Rd, Pd, were characterised as part of the works in terms of their suitability for the planned experiments with the weighted scores method. Design/methodology/approach: A dendrological matrix was used for selection of a noble metal, thus employing a procedural benchmarking method. Findings: The heuristic investigations conducted have revealed that, considering the criteria used for the assessment of the potential and attractiveness of the analysed metals, platinum was awarded the highest weighted score for the analysed materials. Practical implications: The CNT-NPs nanocomposites fabricated by deposition of nanoparticles of noble metals onto carbon nanotubes are characterised by subtle electrical properties and a highly developed specific surface, which makes its particularly suitable as active elements of industrial gas sensors such as: H2, CO, CO2, NH3, NO2, CH4, H2S. Moreover, applications are expected of such nanocomposites in biomedicine as glucose and cholesterol sensors. Originality/value: The selection of a platinum group metal as a constituent component of a nanocomposite consisting of carbon nanotubes and nanoparticles, using the procedural benchmarking technique.

20

Synteza nanocząstek platyny w środowisku wodnym przy użyciu dimetyloaminoboranu jako reduktora

Wojnicki M., Fitzner K.

Rudy i Metale Nieżelazne

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2013

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R. 58, nr 4

182-186

PL

W artykule zbadano wpływ stężenia prekursora, reduktora i czynnika stabilizującego na rozmiar i dystrybucję rozmiaru otrzymywanych nanocząstek platyny. Jako stabilizatory stosowano alkohol poliwinylowy(PVA), poliwinylopirolidon (PVP) oraz cetyltrimetyloamino bromianowy. Wykazano, iż istotnym czynnikiem mającym wpływ na wielkość i dystrybucję rozmiaru nanocząstek platyny ma rodzaj zastosowanego stabilizatora. Równie istotnym czynnikiem jest wpływ stężenia początkowego prekursora. W badaniach wykazano również, iż stężenie początkowe reduktora tylko w niewielkim stopniu ma wpływ na wielkość otrzymywanych nanocząstek.

EN

In the present studies, the influence of initial concentration of precursor, reducing agent and stabilizing agents on the platinum nanoparticles size and size distribution was investigated. As a stabilizing agents, polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP) and cetrimonium bromide (CTAB) were used. It was shown, that the applied stabilizing agent has significant influence on the particles size and size distribution. Moreover, the influence of precursor initial concentration has significant impact on the final particles size. It was also found that reductant initial concentration also plays an important role during the nanoparticles synthesis process. However, its impact on the final particles size and size distribution in small.