Journal articles on the topic 'Platinum Group Metals (PGM)'
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1
Thompson, David T. "Catalysis by Gold/Platinum Group Metals." Platinum Metals Review 48, no. 4 (October 1, 2004): 169–72. http://dx.doi.org/10.1595/003214004x484169172.
Abstract:
The recent surge of new interest in catalysis by gold (–) has led researchers to investigate the effects of adding other metals to the gold. As a result, there are a number of reactions with potential for industrial application where combinations of gold with a platinum group metal (pgm) have been shown to have advantages over either gold or the pgm alone. These findings are expected to lead to applications in chemical processing, pollution control and fuel cell applications. Here, a number of catalytic processes that have benefited from the synergy between a pgm and gold are described, and some interesting reports from recent conferences are highlighted.
2
Kulikov, M., and E. Kopishev. "Review: Extraction of platinum group metals from catalytic converters." BULLETIN of the L.N. Gumilyov Eurasian National University. Chemistry. Geography. Ecology Series 142, no. 1 (2023): 37–71. http://dx.doi.org/10.32523/2616-6771-2023-142-1-37-71.
Abstract:
Platinum group metals (PGM) are widely used in catalytic industry due to their outstanding physical and chemical properties (high-temperature stability, high catalyst activity, high heat resistance, high corrosion resistances). They are used in medical fields, electronics, oil refining, production of ammonia, fuel cells, automotive industry. Catalytic wastes are an important secondary source of metals because recycling of wastes is more economical and ecological way of metals obtaining compared to mining from ores. Spent automotive catalyst is a rich source of platinum group metals [PGM: platinum (Pt), palladium (Pd), and rhodium (Rh)] which contains higher concentrations of PGM than found in natural ores. This review presents the analysis of the recovery methods of platinum group metals from spent catalysts and their advantages and disadvantages. As a result, all methods were analyzed and the most promising (most environmentally friendly and economical) was pointed out.
3
Kulikov, M., and E. Kopishev. "Review: Extraction of platinum group metals from catalytic converters." BULLETIN of L.N. Gumilyov Eurasian National University. CHEMISTRY. GEOGRAPHY. ECOLOGY Series 142, no. 1 (2023): 36–73. http://dx.doi.org/10.32523/2616-6771-2023-142-1-36-73.
Abstract:
Platinum group metals (PGM) are widely used in catalytic industry due to their outstanding physical and chemical properties (high-temperature stability, high catalyst activity, high heat resistance, high corrosion resistances). They are used in medical fields, electronics, oil refining, production of ammonia, fuel cells, automotive industry. Catalytic wastes are an important secondary source of metals because recycling of wastes is more economical and ecological way of metals obtaining compared to mining from ores. Spent automotive catalyst is a rich source of platinum group metals [PGM: platinum (Pt), palladium (Pd), and rhodium (Rh)] which contains higher concentrations of PGM than found in natural ores. This review presents the analysis of the recovery methods of platinum group metals from spent catalysts and their advantages and disadvantages. As a result, all methods were analyzed and the most promising (most environmentally friendly and economical) was pointed out.
4
Diac, Cornelia, Florentina Iuliana Maxim, Radu Tirca, Adrian Ciocanea, Valeriu Filip, Eugeniu Vasile, and Serban N. Stamatin. "Electrochemical Recycling of Platinum Group Metals from Spent Catalytic Converters." Metals 10, no. 6 (June 19, 2020): 822. http://dx.doi.org/10.3390/met10060822.
Abstract:
Platinum group metals (PGMs: Pt, Pd, and Rh) are used extensively by the industry, while the natural resources are limited. The PGM concentration in spent catalytic converters is 100 times larger than in natural occurring ores. Traditional PGM methods use high temperature furnaces and strong oxidants, thus polluting the environment. Electrochemical studies showed that platinum can be converted to their chloride form. The amount of dissolved PGM was monitored by inductively coupled plasma-optical emission spectroscopy and the structure was identified by ultraviolet-visible spectroscopy. An electrochemistry protocol was designed to maximize platinum dissolution, which was then used for a spent catalytic converter. A key finding is the use of potential step that enhances the dissolution rate by a factor of 4. Recycling rates as high as 50% were achieved in 24 h without any pretreatment of the catalyst. The method developed herein is part of a current need to make the PGM recycling process more sustainable.
5
Murray, Angela J., I. P. Mikheenko, Elzbieta Goralska, N. A. Rowson, and Lynne E. Macaskie. "Biorecovery of Platinum Group Metals from Secondary Sources." Advanced Materials Research 20-21 (July 2007): 651–54. http://dx.doi.org/10.4028/www.scientific.net/amr.20-21.651.
Abstract:
Since 1998 demand for the platinum group metals (PGM) has exceeded supply resulting in large price increases. Undersupply, combined with rising costs prompts environmentally friendly recycling technologies. Leachates containing PGM were produced from secondary waste sources using microwave leaching technology with the aim of recovering precious metals using bacterial biomass. Previous studies showed that metallised biomass exhibits catalytic activity; hence metal is not only recovered but can be converted into a valuable product. Cells of Escherichia coli MC4100 that had been pre-metallised with Pt were more effective at reducing PGM from the leachates. The solid recovered from the leachate onto the bacteria was characterised using X-ray Powder Diffraction (XRD) and Energy Dispersive X-ray Microanalysis (EDX). Metallised biomass was tested for catalytic activity (reduction of Cr(VI) to Cr(III)) to compare the ‘quality’ of polymetallic bacterial-based catalysts versus counterparts made from single and mixed metal model solutions.
6
Du, Lei, Gaixia Zhang, and Shuhui Sun. "Proton Exchange Membrane (PEM) Fuel Cells with Platinum Group Metal (PGM)-Free Cathode." Automotive Innovation 4, no. 2 (April 28, 2021): 131–43. http://dx.doi.org/10.1007/s42154-021-00146-0.
Abstract:
AbstractProton exchange membrane (PEM) fuel cells have gained increasing interest from academia and industry, due to its remarkable advantages including high efficiency, high energy density, high power density, and fast refueling, also because of the urgent demand for clean and renewable energy. One of the biggest challenges for PEM fuel cell technology is the high cost, attributed to the use of precious platinum group metals (PGM), e.g., Pt, particularly at cathodes where sluggish oxygen reduction reaction takes place. Two primary ways have been paved to address this cost challenge: one named low-loading PGM-based catalysts and another one is non-precious metal-based or PGM-free catalysts. Particularly for the PGM-free catalysts, tremendous efforts have been made to improve the performance and durability—milestones have been achieved in the corresponding PEM fuel cells. Even though the current status is still far from meeting the expectations. More efforts are thus required to further research and develop the desired PGM-free catalysts for cathodes in PEM fuel cells. Herein, this paper discusses the most recent progress of PGM-free catalysts and their applications in the practical membrane electrolyte assembly and PEM fuel cells. The most promising directions for future research and development are pointed out in terms of enhancing the intrinsic activity, reducing the degradation, as well as the study at the level of fuel cell stacks.
7
Devyatykh, E. A., T. O. Devyatykh, and A. N. Boyarsky. "Survey of Methods of Refining Catalysts for the Extraction of Platinum Group Metals." Materials Science Forum 946 (February 2019): 528–32. http://dx.doi.org/10.4028/www.scientific.net/msf.946.528.
Abstract:
Currently, about 80% of all industrial chemical reactions are carried out with the help of catalysts or depend on catalytic processes. In this case, catalysts containing platinum group metals (hereinafter - PGM) occupy a special position, due to their high catalytic activity and selectivity. A significant part of the net global demand for PGM is for the production of catalysts, accounting for approximately 45% for platinum, 30% for palladium, 92% for rhodium, 35% for ruthenium, 15% for iridium. The most important condition for the economical use of catalysts containing precious metals is their efficient recycling, which will be discussed below.
8
Prichard, Hazel M., Saioa Suárez, Peter C. Fisher, Robert D. Knight, and John S. Watson. "Placer platinum-group minerals in the Shetland ophiolite complex derived from anomalously enriched podiform chromitites." Mineralogical Magazine 82, no. 3 (April 16, 2018): 491–514. http://dx.doi.org/10.1180/minmag.2017.081.099.
Abstract:
ABSTRACTHighly anomalous platinum-group element (PGE) concentrations in the podiform chromitites at the Cliff and Harold's Grave localities in the Shetland ophiolite complex have been well documented previously. The focus of this study is alluvial platinum-group minerals (PGM) located in small streams that drain from the PGE-rich chromitites. The placer PGM assemblage at Cliff is dominated by Pt-arsenides (64%) and Pd-antimonides (17%), with less irarsite–hollingworthite (11%) and minor Pd-sulfides, Pt–Pd–Cu and Pt–Fe alloys and laurite. Gold also occurs with the PGM. Alluvial PGM have average sizes of 20 µm × 60 µm, with sperrylite the largest grain identified at 110 µm in diameter, matching the range reported for the primary PGM in the source rocks. The placer assemblage contains more Pt-bearing and less Pd-bearing PGM compared with the rocks. The more resistant sperrylite and irarsite–hollingworthite grains which are often euhedral become more rounded further downstream whereas the less resistant Pd-antimonides which are commonly subhedral may become striated and etched. Less stable phases such as Pt- and Pd-oxides and other Ni-Cu-bearing phases located in the rocks (i.e. Ru-pentlandite, PtCu, Pd–Cu alloy) are absent in the placer assemblage. Also the scarce PGM (PdHg, Rh- and Ir-Sb) and Os in the rocks are absent. At Harold's Grave only three alluvial PGM (laurite, Ir, Os) and Au were recovered reflecting the limited release of IPGM from chromite grains in the rocks. In this cold climate with high rainfall, where erosion dominates over weathering, the PGM appear to have been derived directly from the erosion of the adjacent PGE-rich source rocks and there is little evidence of in situ growth of any newly formed PGM. Only the presence of dendritic pure Au and Pd-, Cu-bearing Au covers on the surface of primary minerals may indicate some local reprecipitation of these metals in the surficial conditions.
9
Hutchinson, David, Jeffrey Foster, Hazel Prichard, and Sarah Gilbert. "Concentration of Particulate Platinum-Group Minerals during Magma Emplacement; a Case Study from the Merensky Reef, Bushveld Complex." Journal of Petrology 56, no. 1 (January 1, 2015): 113–59. http://dx.doi.org/10.1093/petrology/egu073.
Abstract:
Abstract The petrology, mineralogy and geochemistry of a section of the Merensky Reef at Bafokeng Rasimone Platinum Mine (BRPM) are described. A model for the formation of platinum-group minerals (PGM), sulphide and chromitite is proposed that explains the stratigraphic relationships observed in the Merensky Reef, both at BRPM and at other locations in the Bushveld Complex. To achieve this it is necessary to understand platinum-group element (PGE) behaviour in naturally occurring mafic systems and for this reason comparisons are drawn from core TN207 through the Platreef at Tweefontein. The common link between the Platreef and Merensky Reef is the presence of unusually high concentrations of As, Sb, Bi and Te that promote the crystallisation of semi-metal bearing PGM from sulphide liquids. Under conditions of increasing semi-metal contamination, Pt is the first PGE to be extracted from a sulphide liquid followed by Rh, Ru, Os and Ir. While some Pd is released to form Pd-PGM much of it remains within the Ni-rich sulphide phase that crystallizes to form pentlandite. A critical aspect is the timing of their introduction into the magmatic system. For the Merensky magmas, contamination occurred predominantly within a staging chamber owing to wall-rock interaction with Transvaal sediments. This led to the formation of sulphide liquids that captured PGE and, ultimately, the crystallization of Pt- and Ru-PGM. The extreme enrichment in PGE and the high Pt/Pd ratios in the Merensky chromitites are attributed to density-driven concentration of PGM transported by magmas displaced from a staging chamber. Emplacement of these magmas into the Bushveld Complex resulted in thermo-mechanical erosion of the floor and deposition of chromites + sulphides + PGM. In places, these assemblages collected in sedimentary-like scour channels. In the Platreef, contamination occurred largely after magma emplacement owing to interaction with the local Transvaal sediments. As a result, mechanical separation of PGM did not occur and most PGM remain spatially associated with their original sulphide hosts.The Merensky Reef is a prime example of highly efficient PGE concentration resulting from mechanical processes, whereas the Platreef is a prime example of highly efficient PGE removal from sulphide liquids in response to extreme contamination by semi-metals.
10
Men Truong, Van, Julian Richard Tolchard, Jørgen Svendby, Maidhily Manikandan, Hamish A. Miller, Svein Sunde, Hsiharng Yang, Dario R. Dekel, and Alejandro Oyarce Barnett. "Platinum and Platinum Group Metal-Free Catalysts for Anion Exchange Membrane Fuel Cells." Energies 13, no. 3 (January 27, 2020): 582. http://dx.doi.org/10.3390/en13030582.
Abstract:
The development of active hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR) catalysts for use in anion exchange membrane fuel cells (AEMFCs), which are free from platinum group metals (PGMs), is expected to bring this technology one step closer to commercial applications. This paper reports our recent progress developing HOR Pt-free and PGM-free catalysts (Pd/CeO2 and NiCo/C, respectively), and ORR PGM-free Co3O4 for AEMFCs. The catalysts were prepared by different synthesis techniques and characterized by both physical-chemical and electrochemical methods. A hydrothermally synthesized Co3O4 + C composite ORR catalyst used in combination with Pt/C as HOR catalyst shows good H2/O2 AEMFC performance (peak power density of ~388 mW cm−2), while the same catalyst coupled with our flame spray pyrolysis synthesised Pd/CeO2 anode catalysts reaches peak power densities of ~309 mW cm−2. Changing the anode to nanostructured NiCo/C catalyst, the performance is significantly reduced. This study confirms previous conclusions, that is indeed possible to develop high performing AEMFCs free from Pt; however, the challenge to achieve completely PGM-free AEMFCs still remains.
11
Tobón, Mónica, Marion Weber, Joaquín A. Proenza, Thomas Aiglsperger, Sebastián Betancur, Júlia Farré-de-Pablo, Carlos Ramírez, and Núria Pujol-Solà. "Geochemistry of Platinum-Group Elements (PGE) in Cerro Matoso and Planeta Rica Ni-Laterite deposits, Northern Colombia." Boletín de la Sociedad Geológica Mexicana 72, no. 3 (November 28, 2020): A201219. http://dx.doi.org/10.18268/bsgm2020v72n3a201219.
Abstract:
Platinum-group elements (PGE) are included among the so-called critical metals, and are essential metals for the technological industry. However, there are very few deposits in the world from which these metals can be extracted. The present work investigates three Ni-laterite profiles (hydrous Mg silicate type) formed over the ultramafic rocks of Cerro Matoso and Planeta Rica in Colombia. The main goal is to determine their PGE concentration and distribution, as well as to identify the carrier phases of these noble metals. The highest PGE contents in Cerro Matoso and Planeta Rica are concentrated in the limonite horizon (141–272 ppb), showing a strong decrease towards the saprolite and the underlying serpentinized peridotite (parent rock; < 50 ppb). The highest concentrations correspond to Pt>Ru>Pd and the lowest to Rh<Os<Ir. Such distribution indicates that PGE are mobilized in different proportions by the laterization processes. The high affinity between PGE and Fe favors the formation of PGE-Fe mineral alloys such as the Pt-Ir-Fe-Ni minerals hosted by Fe-oxyhydroxide found in the limonite–saprolite transition zone in Planeta Rica. In addition, in the same zone, nanoparticles of Pt (< 1 µm) were found within framboidal pyrite. Both types of platinum group minerals (PGM) are secondary in origin. In the case of Pt-Ir-Fe-Ni alloys, this interpretation is supported by their morphology and chemical composition, which is comparable with PGE-Fe-Ni alloys found in laterites of Dominican Republic. In the case of Pt nanoparticle, textural relations suggest the neoformation of PGM adhered to the porous edges of altered pyrite. Cerro Matoso and Planeta Rica should be considered as unconventional PGE deposits, if adequate recovery processes can be applied for their recovery as by-products during Ni (+Co) production.
12
Aiglsperger, Thomas, José M. González-Jiménez, Joaquín A. Proenza, Salvador Galí, Francisco Longo, William L. Griffin, and Suzanne Y. O’Reilly. "Open System Re-Os Isotope Behavior in Platinum-Group Minerals during Laterization?" Minerals 11, no. 10 (October 1, 2021): 1083. http://dx.doi.org/10.3390/min11101083.
Abstract:
In this short communication, we present preliminary data on the Re-Os isotopic systematics of platinum-group minerals (PGM) recovered from different horizons in the Falcondo Ni-laterite in the Dominican Republic. The results show differences in the Os-isotope composition in different populations of PGM: (i) pre-lateritic PGM yield 187Os/188Os varying from 0.11973 ± 0.00134 to 0.12215 ± 0.00005 (2σ uncertainty) whereas (ii) lateritic PGM are more radiogenic in terms of 187Os/188Os (from 0.12390 ± 0.00001 to 0.12645 ± 0.00005; 2σ uncertainty). We suggest that these differences reflect the opening of the Re-Os system in individual grains of PGM during lateritic weathering. The implications of these results are twofold as they will help to (1) elucidate the small-scale mobility of noble metals in the supergene setting and therefore the possible formation of PGM at these very low temperatures, (2) better refine the Os-isotopic datasets of PGM that are currently being used for defining dynamic models of core–mantle separation, crustal generation, and fundamental plate-tectonic processes such as the opening of oceans.
13
Nassar, N. T. "Limitations to elemental substitution as exemplified by the platinum-group metals." Green Chemistry 17, no. 4 (2015): 2226–35. http://dx.doi.org/10.1039/c4gc02197e.
14
Aleksandrova, Tatyana, and Cyril О’Connor. "Processing of platinum group metal ores in Russia and South Africa: current state and prospects." Journal of Mining Institute 244 (July 30, 2020): 462–73. http://dx.doi.org/10.31897/pmi.2020.4.9.
Abstract:
The presented study is devoted to a comparative review of the mineral raw material base of platinum group metals (PGMs) and technologies of their processing in South Africa and Russia, the largest PGM producers. Mineralogical and geochemical classification and industrial value of iron-platinum and platinum-bearing deposits are presented in this work. The paper also reviews types of PGM ore body occurrences, ore processing methods (with a special focus on flotation processes), as well as difficulties encountered by enterprises at the processing stage, as they increase recovery of the valuable components. Data on mineralogical features of PGM deposits, including the distribution of elements in the ores, are provided. The main lines of research on mineralogical features and processing of raw materials of various genesis are identified and validated.
Sulfide deposits are found to be of the highest industrial value in both countries. Such unconventional PGM sources, as black shale, dunites, chromite, low-sulfide, chromium and titanomagnetite ores, anthropogenic raw materials, etc. are considered. The main lines of research that would bring into processing non-conventional metal sources are substantiated.
Analysis of new processing and metallurgical methods of PGM recovery from non-conventional and industrial raw materials is conducted; the review of existing processing technologies for platinum-bearing raw materials is carried out. Technologies that utilize modern equipment for ultrafine grinding are considered, as well as existing reagents for flotation recovery; evaluation of their selectivity in relation to platinum minerals is presented.
Basing on the analysis of main technological processes of PGM ore treatment, the most efficient schemes are identified, i.e.,gravity and flotation treatment with subsequent metallurgical processing.
15
Swider-Lyons, Karen, Sejal Patel, and Chris Rainford. "Projected Fuel Cell Stack Costs Using Non-PGM Cathode Electrocatalysts." ECS Transactions 112, no. 4 (September 29, 2023): 225–32. http://dx.doi.org/10.1149/11204.0225ecst.
Abstract:
Proton exchange membrane (PEM) fuel cells presently contain platinum (Pt) at their cathode and anode for catalysis of oxygen and hydrogen, respectively. Replacing the Pt at the fuel cell cathode with electrocatalysts having no precious group metals (non-PGM or PGM-free) is a vibrant research area, aiming to protect against any rapid increase in the cost ofplatinum. However, the activity of non-PGM catalysts is presently low, so more cells, including the PEM, bipolar plates, etc., are needed to reach a rated power for a stack with a non-PGM cathode. Technoeconomic analysis (TEA) shows that a stack with non-PGM catalysts would be approximately 2.9× the size of a stack with a standard Pt cathode catalyst and would cost about 2.3× more. The stacks must still be recycled to reclaim the Pt at the anode catalyst, but recycling becomes less cost competitive as the amountof Pt in stack decreases. We conclude that for economic viability, the performance and durability of non-PGM catalysts must approach that of Pt, and researchers should investigate non-PGM anodes to eliminate recycling needs.
16
SUZUKI, Shigeki, Masahiko OGINO, and Takeshi MATSUMOTO. "Recovery of Platinum Group Metals at Nippon PGM Co., Ltd." Journal of MMIJ 123, no. 12 (2007): 734–36. http://dx.doi.org/10.2473/journalofmmij.123.734.
17
Odularu, Ayodele T., Peter A. Ajibade, Johannes Z. Mbese, and Opeoluwa O. Oyedeji. "Developments in Platinum-Group Metals as Dual Antibacterial and Anticancer Agents." Journal of Chemistry 2019 (November 6, 2019): 1–18. http://dx.doi.org/10.1155/2019/5459461.
Abstract:
Platinum-group (PG) complexes have been used as antibacterial and anticancer agents since the discovery of cisplatin. The science world still requires improvement on these complexes because of multidrug and antineoplastic resistances. This review observes discoverers and history of these platinum-group metals (PGMs), as well as their beneficial applications. The focus of this study was biological applications of PGMs in relation to human health. Sandwich and half-sandwich PGM coordination compounds and their metal nanoparticles give improved results for biological activities by enhancing efficient delivery of both antibacterial and anticancer drugs, as well as luminescent bioimaging (biomarkers) for biological identifications.
18
Andersen, Shuang Ma, and Raghunandan Sharma. "PGM Recovery: Maximizing PGM Dissolution through Minimizing Ostwald Ripening." ECS Meeting Abstracts MA2023-02, no. 40 (December 22, 2023): 1952. http://dx.doi.org/10.1149/ma2023-02401952mtgabs.
Abstract:
Efficient recovery of platinum group metals (PGMs) through electrochemical means using mild conditions is of significant impact from both the industrial and the environmental points of view. Owing to their large surface-to-volume ratio, fast dissolution of PGM nanoparticles is possible through potential cycling between oxidizing and reducing potentials, leading to formation and dissolution of surface-oxide layer (transient dissolution). However, at reducing potentials, reduction of the dissolved metal species on the source nanoparticles leads to enhance the Ostwald ripening process1 and hence to decrease the overall dissolution efficiency significantly. In this talk, we present strategies to accelerate dissolution of PGM nanoparticles by limiting Ostwald ripening through (1) use of surface switching species (SSS), which selectively block the PGM surface to inhibit redeposition induced particle growth at reducing condition and expose the PGM surface to facilitate dissolution at oxidation condition, respectively2. (2) use of an auxiliary deposition system to continuously remove the dissolved PGM species through reaction kinetic manipulation3. Such surface relegation property to depress unwanted process and assist desired reaction documents an alternative and efficient approach for precious metal electrochemical recovery. References Sharma, R.; Andersen, S. M., Quantification on Degradation Mechanisms of Polymer Electrolyte Membrane Fuel Cell Catalyst Layers during an Accelerated Stress Test. ACS Catal. 2018, 8 (4), 3424-3434. Sharma, R.; Simonsen, S. B.; Morgen, P.; Andersen, S. M., Inhibition of Ostwald ripening through surface switching species during potentiodynamic dissolution of platinum nanoparticles as an efficient strategy for platinum group metal (PGM) recovery. Electrochim. Acta 2019, 321, 11. Sharma, R.; Gyergyek, S.; Andersen, S. M., Environmentally and Industrially Friendly Recycling of Platinum Nanoparticles Through Electrochemical Dissolution-Electrodeposition in Acid-Free/Dilute Acidic Electrolytes. ChemSusChem 2018, 11 (21), 3742-3750.
19
Trinh, Ha Bich, Seunghyun Kim, Jaeryeong Lee, and Jae-chun Lee. "Variation in the determination of platinum group metals using ICP OES induced by the effect of complex matrices and the correction method based on multivariate calibration." Journal of Analytical Atomic Spectrometry 37, no. 2 (2022): 330–37. http://dx.doi.org/10.1039/d1ja00442e.
Abstract:
We reveal the effect of matrix complexity on the quantitative determination of platinum group metals (PGMs) using inductively coupled plasma optical emission spectrometry. The variation in PGM determination is compensated by employing the multivariate calibration technique.
20
Petek, Urša, Francisco Ruiz-Zepeda, Marjan Bele, and Miran Gaberšček. "Nanoparticles and Single Atoms in Commercial Carbon-Supported Platinum-Group Metal Catalysts." Catalysts 9, no. 2 (February 1, 2019): 134. http://dx.doi.org/10.3390/catal9020134.
Abstract:
Nanoparticles of platinum-group metals (PGM) on carbon supports are widely used as catalysts for a number of chemical and electrochemical conversions on laboratory and industrial scale. The newly emerging field of single-atom catalysis focuses on the ultimate level of metal dispersion, i.e. atomically dispersed metal species anchored on the substrate surface. However, the presence of single atoms in traditional nanoparticle-based catalysts remains largely overlooked. In this work, we use aberration-corrected scanning transmission electron microscope to investigate four commercially available nanoparticle-based PGM/C catalysts (PGM = Ru, Rh, Pd, Pt). Annular dark-field (ADF) images at high magnifications reveal that in addition to nanoparticles, single atoms are also present on the surface of carbon substrates. Scanning electron microscopy, X-ray diffraction and size distribution analysis show that the materials vary in nanoparticle size and type of carbon support. These observations raise questions about the possible ubiquitous presence of single atoms in conventional nanoparticle PGM/C catalysts and the role they may play in their synthesis, activity, and stability. We critically discuss the observations with regard to the quickly developing field of single atom catalysis.
21
Straka, Martin, Peter Kacmary, and Jakub Kovalcik. "Technology and possibilities of recycling catalysts." Acta Tecnología 09, no. 04 (December 31, 2023): 129–32. http://dx.doi.org/10.22306/atec.v9i4.182.
Abstract:
The presented article focuses on the possibilities of recycling three types of catalysts. These catalyst types will undergo examination, measurement, and analysis with the aim of identifying which of these catalysts contains the necessary number of precious metals (PGM - Platinum Group Metals). PGM metals are among the rarest and most challenging-to-obtain elements on Earth, carrying a high risk of supply shortage. Nevertheless, they are crucial for the European Union (EU) and the automotive industry. Not every catalyst used in the market is suitable for recycling due to the absence of these precious metal particles.
22
ALEKSEEV, YAROSLAV, YEVSEI ZASKIND, and OLGA KONKINA. "Mineral resource base of platinum group metals in Russia: state, development and prospects until 2040." Domestic geology, no. 2 (May 25, 2022): 3–11. http://dx.doi.org/10.47765/0869-7175-2022-10006.
Abstract:
In this work, we present the state and reproduction structure of the mineral resource base (MRB) of platinum group metals (PGM) from 2005 to 2020 as well as a forecast of its development up to 2040. Moreover, the analysis the movement of reserves and their redemption by types of deposits was carried out.
23
Bai, Lu, Jingjun Liu, Chun Jin, Jin Zhang, and Feng Wang. "Heteroatom-doped carbon interpenetrating networks: a signpost to achieve the best performance of non-PGM catalysts for fuel cells." Journal of Materials Chemistry A 8, no. 36 (2020): 18767–77. http://dx.doi.org/10.1039/d0ta06794f.
Abstract:
Non-platinum group metal (non-PGM) catalysts, constructed from cheap and abundant carbon, nitrogen and 3d transition metals as bricks, have been regarded as the most promising candidates for the oxygen reduction reaction (ORR) in fuel cells and metal–air batteries.
24
Mack, C. L., B. Wilhelmi, J. R. Duncan, and J. E. Burgess. "Biosorptive recovery of platinum from platinum group metal refining wastewaters by immobilised Saccharomyces cerevisiae." Water Science and Technology 63, no. 1 (January 1, 2011): 149–55. http://dx.doi.org/10.2166/wst.2011.025.
Abstract:
The process of platinum group metal (PGM) refining can be up to 99.99% efficient at best, and although it may seem small, the amount of valuable metal lost to waste streams is appreciable enough to warrant recovery. The method currently used to remove entrained metal ions from refinery wastewaters, chemical precipitation, is not effective for selective recovery of PGMs. The yeast Saccharomyces cerevisiae has been found capable of sorbing numerous precious and base metals, and is a cheap and abundant source of biomass. In this investigation, S. cerevisiae was immobilised using polyethyleneimine and glutaraldehyde to produce a suitable sorbent, capable of high platinum uptake (150–170 mg/g) at low pH (<2). The sorption mechanism was found to be a chemical reaction, which made effective desorption impossible. When applied to PGM refinery wastewater, two key wastewater characteristics limited the success of the sorption process; high inorganic ion content and complex speciation of the platinum ions. The results proved the concept principle of platinum recovery by immobilised yeast biosorption and indicated that a more detailed understanding of the platinum speciation within the wastewater is required before biosorption can be applied. Overall, the sorption of platinum by the S. cerevisiae sorbent was demonstrated to be highly effective in principle, but the complexity of the wastewater requires that pretreatment steps be taken before the successful application of this process to industrial wastewater.
25
Zimmermann, S., A. von Bohlen, J. Messerschmidt, and B. Sures. "Accumulation of the precious metals platinum, palladium and rhodium from automobile catalytic converters in Paratenuisentis ambiguus as compared with its fish host, Anguilla anguilla." Journal of Helminthology 79, no. 1 (March 2005): 85–89. http://dx.doi.org/10.1079/joh2004261.
Abstract:
AbstractThe platinum group metals (PGM) Pt, Pd and Rh are emitted into the environment mainly by catalytic exhaust gas converters of cars. As PGM accumulate in sediments of aquatic ecosystems, the study was focused on the uptake of the noble metals by European eels, Anguilla anguilla infected with the acanthocephalan Paratenuisentis ambiguus. Eels were exposed to ground catalytic converter material for six weeks. After exposure Pt and Pd were detected in the liver and kidney of the eels and in the parasites. Palladium was also found in fish muscle and intestine. No Rh uptake by the eel tissues and the parasites occurred. Paratenuisentis ambiguus contained the highest levels of both metals with 40 times higher Pt concentrations and four times higher Pd concentrations than the liver of its host. Due to its accumulation capacity for PGM, P. ambiguus can be applied as a sensitive accumulation indicator in field studies to assess the degree of environmental PGM contamination in aquatic ecosystems.
26
Oberthür, Thomas, Frank Melcher, Tobias Fusswinkel, Alfons M. van den Kerkhof, and Graciela M. Sosa. "The hydrothermal Waterberg platinum deposit, Mookgophong (Naboomspruit), South Africa. Part 1: Geochemistry and ore mineralogy." Mineralogical Magazine 82, no. 3 (April 12, 2018): 725–49. http://dx.doi.org/10.1180/minmag.2017.081.073.
Abstract:
ABSTRACTThe Waterberg platinum deposit is an extraordinary example of a vein-type hydrothermal quartz-hematite-PGE (platinum-group element) mineralization. This study concentrates on the geochemical character of the ores and the platinum-group mineral (PGM) assemblage by application of reflected-light and scanning electron microscopy followed by electron probe microanalysis.The PGM-bearing quartz veins show multiple banding indicating numerous pulses of fluid infiltration. Mineralization was introduced contemporaneously with the earliest generation of vein quartz and hematite. High oxygen and low sulfur fugacities of the mineralizing fluids are indicated by hematite as the predominant opaque mineral and the lack of sulfides.The ‘Waterberg type’ mineralization is characterized by unique metal proportions, namely Pt>Pd>Au, interpreted as a fingerprint to the cradle of the metals, namely rocks and ores of the Bushveld Complex, or reflecting metal fractionation during ascent of an oxidized, evolving fluid. The PGM assemblage signifies three main depositional and alteration events. (1) Deposition of native Pt and Pt–Pd alloys (>90% of the PGM assemblage) and Pd–Sb–As compounds (Pt-rich isomertieite and mertieite II) from hydrothermal fluids. (2) Hydrothermal alteration of Pt by Cu-rich fluids and formation of Pt–Cu alloys and hongshiite [PtCu]. (3) Weathering/oxidation of the ores producing Pd/Pt-oxides/hydroxides.Platinum-group element transport was probably by chloride complexes in moderately acidic and strongly oxidizing fluids of relatively low salinity, and depositional temperatures were in the range 400–200°C. Alternatively, quartz and ore textures may hint to noble metal transport in a colloidal form and deposition as gels.The source of the PGE is probably in platiniferous rocks or ores of the Bushveld Complex which were leached by hydrothermal solutions. If so, further Waterberg-type deposits may be present, and a prime target area would be along the corridor of the Thabazimbi-Murchison-Lineament where geothermal springs are presently still active.
27
Perez Bakovic, Sergio Ivan, Alex Keane, Marcelo Carmo, and Diana De Porcellinis. "Reaching PEM Performance Parity with Anion Exchange Membrane Electrolyzers." ECS Meeting Abstracts MA2023-01, no. 36 (August 28, 2023): 2065. http://dx.doi.org/10.1149/ma2023-01362065mtgabs.
Abstract:
Anion exchange membrane (AEM) electrolyzers promise to combine the benefits from proton exchange membrane (PEM) electrolyzers and liquid alkaline electrolyzers. They offer both the compact stack design and high current densities that PEM electrolyzers provide, while also taking advantage of using non-platinum-group-metals (non-PGM) and titanium-free components similar to traditional alkaline electrolyzers. However, AEM stacks and systems must demonstrate competitive performance and durability to allow widespread commercial adoption. As part of AEM development efforts, a comprehensive study has been conducted on the morphology of different porous plates and their impact on the cell performance. The key results demonstrate comparable performance of AEM electrolyzers to PEM electrolyzers under optimized conditions. Different ink formulation and processes have also been evaluated for a series of non-PGM catalysts, while testing their impact on performance and durability. In addition, commercially available AEMs have been evaluated for long term durability in short cell stacks, demonstrating comparable degradation rates to PEM electrolyzer technology.
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Rao, C. R. M., and G. S. Reddi. "Platinum group metals (PGM); occurrence, use and recent trends in their determination." TrAC Trends in Analytical Chemistry 19, no. 9 (September 2000): 565–86. http://dx.doi.org/10.1016/s0165-9936(00)00031-5.
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Miroslaw, Barbara. "Homo- and Hetero-Oligonuclear Complexes of Platinum Group Metals (PGM) Coordinated by Imine Schiff Base Ligands." International Journal of Molecular Sciences 21, no. 10 (May 15, 2020): 3493. http://dx.doi.org/10.3390/ijms21103493.
Abstract:
Chemistry of Schiff base (SB) ligands began in 1864 due to the discovery made by Hugo Schiff (Schiff, H., Justus Liebigs Ann. der Chemie 1864, 131 (1), 118–119). However, there is still a vivid interest in coordination compounds based on imine ligands. The aim of this paper is to review the most recent concepts on construction of homo- and hetero-oligonuclear Schiff base coordination compounds narrowed down to the less frequently considered complexes of platinum group metals (PGM). The combination of SB and PGM in oligonuclear entities has several advantages over mononuclear or polynuclear species. Such complexes usually exhibit better electroluminescent, magnetic and/or catalytic properties than mononuclear ones due to intermetallic interactions and frequently have better solubility than polymers. Various construction strategies of oligodentate imine ligands for coordination of PGM are surveyed including simple imine ligands, non-innocent 1,2-diimines, chelating imine systems with additional N/O/S atoms, classic N2O2-compartmental Schiff bases and their modifications resulting in acyclic fused ligands, macrocycles such as calixsalens, metallohelical structures, nano-sized molecular wheels and hybrid materials incorporating mesoionic species. Co-crystallization and formation of metallophilic interactions to extend the mononuclear entities up to oligonuclear coordination species are also discussed.
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Julsing, H. G., and R. I. McCrindle. "The recovery of precious metals from acidic effluents using sodium formate." Water Science and Technology 42, no. 5-6 (September 1, 2000): 63–69. http://dx.doi.org/10.2166/wst.2000.0496.
Abstract:
At Western Platinum Refinery in South Africa, zinc was used for the reduction of the platinum group metals (PGMs) in acidic effluent (palladium filtrate). Owing to the increasing cost of zinc and the risk of zinc pollution, sodium formate was investigated as an alternative reductant. It was found that pH 1.5 was the optimum starting pH for sodium formate reduction. The optimum concentration of sodium formate was found to be 18 g/dm3 at a temperature of approximately 100°C where the process time was 5 hours. The addition of sodium formate increased the pH of the final reaction mixture to approximately pH 4.5. Palladium was the most effectively reduced PGM, exhibiting an average precipitation efficiency of 98%. Difficulty was experienced with the precipitation of platinum (average precipitation efficiency of 47%). The precipitated PGMs were readily dissolved in hydrochloric acid (6 M) and sodium chlorate (2%). A reduction in costs resulted from the discontinuation of the use of zinc for reduction purposes. An additional advantage was that zinc was no longer introduced into the PGM refinery circuits. This effectively reduced the pollution potential of the acidic effluent.
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Samotaev, Nikolay, Andrey Antonov, Grigory Tsarev, and Andreas Tietz. "Effective Recycling of Spent Auto Catalytic Converters by Using Electrochlorination Method." MATEC Web of Conferences 207 (2018): 03024. http://dx.doi.org/10.1051/matecconf/201820703024.
Abstract:
Modern methods of recycling spent automotive catalysts and their main disadvantages in industrial practice are considered. The electrochlorination method is proposed as the basis of the platinum-group metals (PGM) recycling technology. As the test of proposed technology a few tons of spent automotive catalysts were processed. The results of the work on the extraction of platinum, palladium, rhodium are analyzed. The extraction rates during experiments were reached for Pt - 97%, Pd - 97% and Rh - 80%.
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Antonov, Andrey, Nikolay Samotaev, Andreas Tietz, Grigory Tsarev, Denis Veselov, and Andrey Kirichenko. "Effective Method for the Platinum Group Metals Extracting from Spent Diesel Autocatalysts." Materials Science Forum 977 (February 2020): 218–22. http://dx.doi.org/10.4028/www.scientific.net/msf.977.218.
Abstract:
The team of authors described a solution to the problem of developing a fundamentally new technology for the industrial processing of spent diesel automotive catalysts containing platinum group metals (PGM) and SiC carrier, which has such advantages as carrying out a full processing cycle in one hardware module. The processing of SiC catalyst is extremely difficult by pyrometallurgical methods, but proposed technology is based on the electrochlorination method. The scientific novelty of the proposed method lies in the superposition of two independent electrolysis processes in direct and alternating, with varying frequency, currents under conditions of forced, continuous and complete recondensation of the electrolyte. The study of the diesel catalysts processing by the electrochlorination method have carried out.
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Saternus, M., A. Fornalczyk, and J. Cebulski. "Analysis of Platinum Content in Used Auto Catalytic Converter Carriers and the Possibility of its Recovery." Archives of Metallurgy and Materials 59, no. 2 (June 1, 2014): 557–64. http://dx.doi.org/10.2478/amm-2014-0092.
Abstract:
Abstract At present, every launched car must be equipped with a catalytic converter, in which the precious metals such as platinum, palladium and rhodium play catalytic role. Catalytic converters have a limited life time, therefore they have to be replaced and become a valuable source of platinum group metals (PGM). Currently in the world, used auto catalytic converters are processed in pyrometallurgical or hydrometallurgical way. However, the first step of such treatment should be a chemical analysis. In the paper catalytic carriers were analysed taking into account the level of platinum. Scanning electron microscope was used. The analysis concentrated on testing samples coming from different catalytic carriers. The structure of tested samples, chemical analysis and X-ray energy spectra (EDS) where presented as well as the discussion of obtained results and possible methods of platinum recovery.
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Fornalczyk, A., M. Kraszewski, J. Willner, J. Kaduková, A. Mrážiková, R. Marcinčáková, and O. Velgosová. "Dissolution of Metal Supported Spent Auto Catalysts in Acids." Archives of Metallurgy and Materials 61, no. 1 (March 1, 2016): 233–36. http://dx.doi.org/10.1515/amm-2016-0043.
Abstract:
Metal supported auto catalysts, have been used in sports and racing cars initially, but nowadays their application systematically increases. In Metal Substrate (supported) Converters (MSC), catalytic functions are performed by the Platinum Group Metals (PGM): Pt, Pd, Rh, similarly to the catalysts on ceramic carriers. The contents of these metals make that spent catalytic converters are valuable source of precious metals. All over the world there are many methods for the metals recovery from the ceramic carriers, however, the issue of platinum recovery from metal supported catalysts has not been studied sufficiently yet. The paper presents preliminary results of dissolution of spent automotive catalyst on a metal carrier by means of acids: H2SO4, HCl, HNO3, H3PO4. The main assumption of the research was the dissolution of base metals (Fe, Cr, Al) from metallic carrier of catalyst, avoiding dissolution of PGMs. Dissolution was the most effective when concentrated hydrochloric acid, and 2M sulfuric acid (VI) was used. It was observed that the dust, remaining after leaching, contained platinum in the level of 0.8% and 0.7%, respectively.
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Osmieri, Luigi, and Piotr Zelenay. "(Invited) Towards Entirely Platinum Group Metal-Free Water Electrolyzers: Innovative Electrocatalysts for Oxygen Evolution and Hydrogen Evolution Reactions." ECS Meeting Abstracts MA2022-01, no. 34 (July 7, 2022): 1379. http://dx.doi.org/10.1149/ma2022-01341379mtgabs.
Abstract:
Making the production of “green” hydrogen (H2) cost-effective requires the development of high-performance and affordable low-temperature water electrolyzers (LTWE).1 Currently, the most mature technology for H2 production using renewable electricity is the liquid alkaline electrolysis (AE). This technology suffers several major drawbacks such as gas crossover, relatively low current density, and the use of highly corrosive concentrated alkaline solutions (20-40% KOH). Proton exchange membrane (PEM) electrolysis, a valid alternative to AE technology, already commercialized on a large scale, enables operation on pure water thus eliminating corrosion, reducing gas crossover and allowing higher current density. However, the main drawback of PEM electrolyzers is the need of very expensive and rare platinum group metals (PGMs) such as Ir and Pt as catalysts for oxygen evolution reaction (OER) at the anode and hydrogen evolution reaction (HER) at the cathode, respectively.2 Recent advancements in performance and stability of anion exchange membranes (AEMs) have enabled a new type of alkaline membrane-based LTWE operating on pure water and with PGM-free catalysts.3,4 If successful, this new AEM-LTWE technology will allow to overcome the drawbacks of AEs and PEM-LTWEs while benefiting from their respective advantages in a major breakthrough in the production of “green” H2 at a low cost. In this scenario crucial is the development of high-performance PGM-free electrocatalysts for both OER and HER. Due to the operation at high potentials, carbon-based catalysts and supports cannot be used at the anode. Therefore, the most common PGM-free anode catalysts are based on transition metal oxides, which suffer, however, from low surface area and electronic conductivity, limiting the electrocatalytic performance.5,6 The catalysts with the most promising OER activity in alkaline environment are Ni-based alloys, oxides, and (oxy)hydroxides.7 The combination of Ni with other first-row transition metals such as Fe and Co was found to increase the OER catalytic activity.8,9 In this work, we present a new method for synthesizing NiFe OER catalysts. The catalyst was synthesized via a sol-gel method, followed by a thermal treatment. The impact on the OER activity in alkaline liquid electrolyte of different synthesis parameters such as the Ni-to-Fe atomic ratio, the addition of a third transition metal (e.g., Co, Mn), the thermal treatment temperature and atmosphere were investigated. Then, the most promising electrocatalysts were tested in an AEM-LTWE operating with pure water and supporting electrolyte solution. Bimetallic HER PGM-free catalysts were also developed by combining one a first-row transition metal, e.g. Ni, with a second-row transition metal, e.g. Mo. These HER catalysts were synthesized by either (i) using the sol-gel approach described above or (ii) via a metal organic framework (MOF) method similar to the one used in the synthesis of “atomically dispersed” M-N-C catalysts for oxygen reduction reaction.10 References A. M. Oliveira, R. R. Beswick, and Y. Yan, Curr. Opin. Chem. Eng., 33, 100701 (2021). H. A. Miller et al., Sustain. Energy Fuels, 4, 2114–2133 (2020). J. Xiao et al., ACS Catal., 11, 264–270 (2021). D. Li et al., Nat. Energy, 5, 378–385 (2020). Q. Gao et al., Chem. Eng. J., 331, 185–193 (2018). D. Xu et al., ACS Catal., 9, 7–15 (2019). S. Fu et al., Nano Energy, 44, 319–326 (2018). G. Zhang et al., Appl. Catal. B Environ., 286, 119902 (2021). P. Chen and X. Hu, Adv. Energy Mater., 10, 1–6 (2020). Y. He et al., Energy Environ. Sci., 12, 250–260 (2019).
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Link, Achim, Patrick Furer, Matthew L. Clarke, and Marc Müller. "Towards the Industrial Implementation of Mn-based Catalyst for the Hydrogenation of Ketones and Carboxylic Esters." CHIMIA 78, no. 3 (March 27, 2024): 118–22. http://dx.doi.org/10.2533/chimia.2024.118.
Abstract:
There is a constant pressure in industry to move away from platinum group metals (PGM) and achieve more environmentally friendly and sustainable production processes in the future. Recently developed Mn-based catalysts offer an interesting opportunity to complement established catalysts based on Ru. In this article, recent achievements in the field are highlighted and recent achievements in the collaboration of Solvias AG with the group of Prof. M. Clarke towards the implementation of these catalysts on industrial scale are outlined.
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Braynchaninova, N. I., A. B. Makeyev, and A. R. Makavetskas. "«Platinum» from the collection of A.F. Keller in the State geological museum RAS." Proceedings of higher educational establishments. Geology and Exploration, no. 3 (June 28, 2017): 70–77. http://dx.doi.org/10.32454/0016-7762-2017-3-70-77.
Abstract:
The microprobe tests of the supposed platinum from the collection of F.A. Keller at the State geological museum of Russian Academy of Sciences have been carried out for the first time. The results have shown that the samples were indeed acquired in the XIX century in the Urals in Nizhnyi Tagil, a famous industrial area, supplied from Gospodskaya mine, being operated in that times. Concentrate platinum according to the shape and mineral compound corresponds to Isovsko-Turinskaya concentrates from Svetloborsky concentrically zoned dunite-clinopyroxenite platinum-bearing massif. Analyses of the chemical composition of the mineral phases have allowed making a list of the native metals minerals and platinum group minerals (PGM) in this collection: isoferroplatinum, r-isoferroplatinum, golden isoferroplatinum, copper-nickel tetraferroplatinum, osmium, Ru-osmium, iridium, Ru-iridium (ruthenosmiride), fine gold and tin.
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Grilli, Maria Luisa, Anca Elena Slobozeanu, Claudio Larosa, Daniela Paneva, Iakovos Yakoumis, and Zara Cherkezova-Zheleva. "Platinum Group Metals: Green Recovery from Spent Auto-Catalysts and Reuse in New Catalysts—A Review." Crystals 13, no. 4 (March 23, 2023): 550. http://dx.doi.org/10.3390/cryst13040550.
Abstract:
This manuscript reviews the current trends in the recovery of Platinum Group Metals (PGMs) from end-of-life autocatalysts and the aims of the recently funded Marie Sklodowska-Curie Project “Chemistry of Platinum Group Metals-CHemPGM” towards the greening of PGMs recovery processes and the reusing of recovered PGMs for preparation of new catalysts. Together with the analysis of the state of the art recovery of PGMs from spent autocatalysts through pyrometallurgical and hydrometallurgical routes and the recent trends in reducing their environmental impact, also emerging sustainable and green technologies are analyzed. Particular focus is given on the mechanochemical processing as a promising sustainable route not only for the pretreatment of waste materials but also for direct PGMs leaching. The present review identifies also the trends in catalysts for carbon neutrality and the few recent efforts in developing PGM-based catalysts starting directly from the liquor of the leach solutions of spent catalysts envisaging therefore a possible key to close PGMs loop in a more efficient and sustainable way.
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Petrov, Georgiy, Irina Zotova, Tatiana Nikitina, and Svetlana Fokina. "Sorption Recovery of Platinum Metals from Production Solutions of Sulfate-Chloride Leaching of Chromite Wastes." Metals 11, no. 4 (April 1, 2021): 569. http://dx.doi.org/10.3390/met11040569.
Abstract:
This paper discusses the scientific rationale for methods of platinum metals sorption centralization from saturated solutions with a high content of macrocomponents. Methods of sorption centralization of platinum and iridium using local anionites such as AH-31, AB-17-8, Purolite S985 are described. The sorbents used were conditioned to remove organic and mineral impurities. The sorption isotherms of platinum group metals 1/EC=f(1/Cp) at a temperature of 20 °C and a duration of 24 h were plotted. The data on the sorption recovery of platinum and iridium from individual and combined sulfate-chloride solutions were determined. Isotherms of iridium sorption from sulfate-chloride solution are formed. Results of the apparent sorption equilibrium constant and values of standard Gibbs energy (ΔG, kJ/mol) of ion exchange for sorption of platinum and iridium from individual and combined sulfate-chloride solutions are presented. Linearized isotherms and kinetic curves of joint sorption of platinum and iridium from sulfate-chloride solution are described. Comparative sorption of the platinum-group metals (PGM) by anionites AB-17-8 and Purolite S985 from sulfate-chloride solutions is shown. The sorption diagram of platinum and iridium from sulfate-chloride product solutions is presented. It has been revealed that complete recovery is achieved using chelation ion-exchange resin Purolite S985, with recovery of Pt up to 95% and Ir more than 73%. The sorption process is accompanied by intradiffusion constraints that are confirmed by the analysis of kinetic curves using Schmukler and Boyd–Adams models.
40
Gil, S., W. Bialik, M. Saternus, and A. Fornalczyk. "Thermal Balance of the Magneto-Hydro-Dynamic Pump for Recovery of Platinum Group Metals from Spent Auto Catalysts." Archives of Metallurgy and Materials 61, no. 1 (March 1, 2016): 253–56. http://dx.doi.org/10.1515/amm-2016-0047.
Abstract:
Every new car should be equipped with the catalyst, which limits the amount of harmful chemical compounds such as NOx, CH and CO emitted to the air. Auto catalyst consists of the ceramic or metallic carrier, on which is the layer with Platinum Group Metals playing catalytic role. There are many methods using for recovery those valuable metals from spent auto catalyst, however evry of those methods have some limitations. Proces described in the article is the modified method of metal collector, which used magnetohydrodynamic pump. Rotary electromagnetic field generates in the liquid metal rotary current, which as a consequence washing out the PGM metals from the ceramic carriers. Considering the possibilities of commercialization of the described method, the energy balance was made. From that balance the energetic efficiency of the unit was determined and the analysis of the temperature distribution was shown thermographycally.
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Schäfer, J., and H. Puchelt. "Platinum-Group-Metals (PGM) emitted from automobile catalytic converters and their distribution in roadside soils." Journal of Geochemical Exploration 64, no. 1-3 (November 1998): 307–14. http://dx.doi.org/10.1016/s0375-6742(98)00040-5.
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Rinkovec, Jasmina. "Platinum, palladium, and rhodium in airborne particulate matter." Archives of Industrial Hygiene and Toxicology 70, no. 4 (December 1, 2019): 224–31. http://dx.doi.org/10.2478/aiht-2019-70-3293.
Abstract:
AbstractMeasurable quantities of platinum, palladium, and rhodium, even in remote areas of the planet, evidence the global nature of pollution with these metals, mostly from catalytic converters of modern vehicles (other sources are jewellery production, chemical industry, and anticancer drugs). The amount of the platinum group metals (PGMs) emitted from automobile catalysts varies with the type, age, and condition of the engine and the catalyst, as well as the style of driving. Current literature suggests that the concentrations of these metals have increased considerably over the last twenty years, palladium concentrations in particular, as it has been proved more effective catalyst than platinum. However, whether and to what extent the emitted PGMs are toxic for people is still a controversy. The potential health risk from exposure to these elements is most likely for those living in urban environments with busy roads or along major highways. Because of the importance of PGMs and their trace levels in particulate matter, sensitive methods are required for reliable determination. This review discusses particular steps of analytical procedures for PGM quantification in airborne particulate matter and addresses the common preparation, detection, and determination methods.
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Sobrova, Pavlina, Josef Zehnalek, Vojtech Adam, Miroslava Beklova, and Rene Kizek. "The effects on soil/water/plant/animal systems by platinum group elements." Open Chemistry 10, no. 5 (October 1, 2012): 1369–82. http://dx.doi.org/10.2478/s11532-012-0073-7.
Abstract:
AbstractEmissions of toxic substances such as oxides of carbon, nitrogen, sulphur, and, in addition, aromatic hydrocarbons, aldehydes and heavy metals are the most serious problem of road traffic affecting landscape. Platinum group elements (PGE), which are the main component of the catalyst, are one of the main sources of heavy metals in the environment. Here, we review the way by which emissions and forms of the emitted PGE end up in the environment especially to the soil-water-plant-animal system. The major points discussed are the following: 1) the main sources of PGE emission are automobile exhaust catalysts; 2) hospitals, where platinum is widely used to treat malignant neoplasm, and urban waste water belonging to other important sources of PGE in the environment; 3) soil is one of the most important components of the environment that may be contaminated with platinum metals; 4) phytotoxicity of PGE depends on the following conditions: the concentration of metals in the soil, time of exposure, the chemical form of metal, the chemical composition of exposed soil and plant species; 5) animals are also endangered by the increasing concentration of PGE in the environment. Moreover, we pay our attention to thiol-based mechanisms of how an organism protects itself against platinum group elements.
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Khan, Iqra Arabia Ali, Ujwal Shreenag Meda, Amrit Aman, Suresh R, and Rajalakshmi Mudbidre. "Alternatives to Conventional Platinum-Based Catalysts in Polymer Electrolyte Membrane Fuel Cells." ECS Transactions 107, no. 1 (April 24, 2022): 5487–98. http://dx.doi.org/10.1149/10701.5487ecst.
Abstract:
The demand for environmentally friendly power technology for a variety of aircraft applications has risen considerably in recent years as the aviation sector expands to meet the needs of a growing global population. The hydrogen fuel cell, which is a device that converts chemical energy directly to electrical energy, seems to be an alternative solution to conventional systems. The use of Proton Exchange Membrane (PEM) or the Polymer Electrolyte Membrane Fuel Cell (PEMFC) for onboard energy generation is gaining importance. PEMFCs have many advantages over other fuel cells and their room temperature/close to room temperature operation makes them suitable for aviation applications. However, there are a few hurdles, such as the use of platinum catalyst, which accounts for half of the fuel cell's cost, it is readily poisoned by CO, necessitating the installation of a mechanism that eliminates CO in the fuel gas and the use of electrolyte membranes, such as Nafion. As a result, the large-scale use of PEMFC is hampered. Tremendous efforts have been devoted to the development of low-cost platinum free catalysts to replace the existing Platinum Group Metals (PGM) catalyst. This review is on the recent advances in non-noble metal catalysts suitable for PEM fuel cells to reduce the overall cost of the fuel cell system leading to its successful commercialization. Feasibility of replacing platinum-based catalysts, challenges associated with replacing the conventional catalysts, the effectiveness, and performance evaluation of new catalysts in comparison with the current platinum-based catalysts in PEM fuel cells are discussed.
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Andersen, Shuang Ma, Raghunandan Sharma, Lars Christian Larsen, Mikkel Juul Juul Larsen, and Laila Grahl-Madsen. "(Invited) Sustainable Platinum Group Metal (PGM) Recycling of Proton Exchange Membrane Fuel Cells and Electrolyzer Cells (PEMFCs & ECs) As a Vital Step Towards Truly Renewable and Green Energy Conversion Technologies." ECS Meeting Abstracts MA2022-02, no. 40 (October 9, 2022): 1460. http://dx.doi.org/10.1149/ma2022-02401460mtgabs.
Abstract:
Owing to their strong catalytic nature and high robustness under various conditions, platinum group metals (PGMs) are state-of-the-art electrocatalysts for proton exchange membrane fuel cells and electrolyzer cells (PEMFCs & ECs) of superior performance and long stability. However, PGM supplies involving limited natural reserves, energy intensive mining process and related environment issues raise increasing concerns. As an indispensable (though insufficiently developed) aspect of the PEM technologies, sustainable PGM recovery and reuse can fundamentally tackle those concerns and serve as a strong support to further secure widespread commercialization of the technologies. Due to the popular use of perfluorinated sulfonic acid as proton conduction component, PGMs in PEMFCs&ECs are not suitable for recycling through the traditional pyrometallurgical route, which operates at a temperature over 1500°C. Burning of the electrodes releases huge amount of emission, which is not only harmful to the environment and human, but also corrosive to the process infrastructure. An alternative PGM recycling process using a hydro-electrochemical route1, 2 reveals many advantages, including high extraction efficiency, environmental friendliness, recovery of multiple components, low demand for operation conditions & maintenance, etc. Adopting the intrinsic degradation mechanisms of the PGM nanoparticles in combination with surface potential modulation, dissolution behavior of typical PEMFC&EC electrocatalysts have been systematically investigated. Under optimal parameters, a recovery efficiency of over 99% was successfully achieved for platinum electrocatalyst. Moreover, new catalysts prepared from the recycled precursor demonstrated competitiveness to that of commercial equivalents. In project 3R, as a joint effort of fuel cell industries, recycling companies and academics supported by Danish Energy Agency, the achievements document a valuable milestone towards truly renewable and green energy conversion technologies. Acknowledgment Financial support from Danish Energy Agency EUDP project 3R, Nr. 64019-0551; Innovation Fund Denmark, InnoExplorer program, Nr. 9122-00112; Danish ESS lighthouse on hard materials in 3D, SOLID, Grant number 8144-00002B; Energi Fyns Udviklingsfond. Corresponding author Shuang Ma Andersen: mashu@igt.sdu.dk Reference Sharma, R.; Gyergyek, S.; Andersen, S. M. ChemSusChem 2018, 11, (21), 3742-3750. Sharma, R.; Rode Nielsen, K.; Brilner Lund, P.; Bredmose Simonsen, S.; Grahl-Madsen, L.; Ma Andersen, S. ChemElectroChem 2019, 6, (17), 4471-4482.
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Wiecka, Zuzanna, Martyna Rzelewska-Piekut, Irmina Wojciechowska, Karolina Wieszczycka, and Magdalena Regel-Rosocka. "Recovery of Palladium(II) and Platinum(IV) in Novel Extraction Systems." Materials 14, no. 2 (January 8, 2021): 285. http://dx.doi.org/10.3390/ma14020285.
Abstract:
Recovery of platinum group metals (PGM) from complex aqueous solutions generated as a result of leaching of various spent materials (e.g., spent automotive converters) is a vital issue in the context of the circular economy. In this study pyridinium derivatives containing an imidoamide or imine moiety (i.e., 3-[1-(2-ethylhexyloxyimine)methane]-1-propylpyridinium chloride, 3-[1-(decyloxyimine)methane]-1-propylpyridinium chloride, 3-[1-(decyloxyimine)ethane]-1-propylpyridinium chloride and 4-[1-amine(2-ethylhexyloxyimine)]-1-propylpyridinium chloride) are proposed as novel extractants for recovery of palladium(II) and platinum(IV) from model chloride aqueous solutions. The results of liquid-liquid extraction from one-component solutions of palladium(II) or platinum(IV) showed that quaternary pyridinium salts can be used as effective extractants for platinum metal ions. Moreover, PGM extraction from a two-component mixture proved no evident selectivity in the transfer of one of the metal ions to the organic phase. As the best extractant among the investigated ones, D3EI-PrCl (with straight alkyl chain at substituent) can be pointed out, however, problems with effective stripping or phase disengagement after stripping should be indicated as a drawback of the organic phases used. Further investigation should focus on the improvement of the organic phase properties (e.g., increase in hydrophobicity of the extractants and addition of an organic phase modifier) towards stripping efficiency.
47
Wiecka, Zuzanna, Martyna Rzelewska-Piekut, Irmina Wojciechowska, Karolina Wieszczycka, and Magdalena Regel-Rosocka. "Recovery of Palladium(II) and Platinum(IV) in Novel Extraction Systems." Materials 14, no. 2 (January 8, 2021): 285. http://dx.doi.org/10.3390/ma14020285.
Abstract:
Recovery of platinum group metals (PGM) from complex aqueous solutions generated as a result of leaching of various spent materials (e.g., spent automotive converters) is a vital issue in the context of the circular economy. In this study pyridinium derivatives containing an imidoamide or imine moiety (i.e., 3-[1-(2-ethylhexyloxyimine)methane]-1-propylpyridinium chloride, 3-[1-(decyloxyimine)methane]-1-propylpyridinium chloride, 3-[1-(decyloxyimine)ethane]-1-propylpyridinium chloride and 4-[1-amine(2-ethylhexyloxyimine)]-1-propylpyridinium chloride) are proposed as novel extractants for recovery of palladium(II) and platinum(IV) from model chloride aqueous solutions. The results of liquid-liquid extraction from one-component solutions of palladium(II) or platinum(IV) showed that quaternary pyridinium salts can be used as effective extractants for platinum metal ions. Moreover, PGM extraction from a two-component mixture proved no evident selectivity in the transfer of one of the metal ions to the organic phase. As the best extractant among the investigated ones, D3EI-PrCl (with straight alkyl chain at substituent) can be pointed out, however, problems with effective stripping or phase disengagement after stripping should be indicated as a drawback of the organic phases used. Further investigation should focus on the improvement of the organic phase properties (e.g., increase in hydrophobicity of the extractants and addition of an organic phase modifier) towards stripping efficiency.
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Baskaran, Gracelin. "Firms’ approach to mitigating risks in the platinum group metals sector." Mineral Economics 34, no. 3 (February 8, 2021): 385–98. http://dx.doi.org/10.1007/s13563-021-00249-4.
Abstract:
AbstractWith platinum prices declining due to a seismic demand shift and firms grappling with the high cost of labor and prolonged production-stopping labor strikes, the financial sustainability of platinum group metal (PGM) firms has come under duress since 2012. This article seeks to understand how mining firms have reshaped their strategies to ensure financial sustainability while also meeting external expectations of increasing shared-value outcomes by assessing how firms are deploying buffers and bridges. Firms use buffers when they seek to protect core business activities from supply-side and demand-side volatilities by shifting their overall business strategy and bridges to conform with external expectations of improving shared-value outcomes. The article constructs a case study using five sets of data to assess (i) what supply and demand shocks firms are facing; (ii) how they are reshaping their strategies and undertaking activities to protect the firm from these shocks; (iii) what challenges firms face with reaching shared-value outcomes; and (iv) how firms are undertaking activities to improve shared-value outcomes. This article finds that although buffering activities have been successful at increasing the financial sustainability of mining activities, bridging activities have been less successful given that royalties are vulnerable to maladministration, the impact of corporate social investments often short-lived, and insular and local procurement is limited to low-value-added activities, particularly in the context of mechanization. This article seeks to contribute to the body of literature on how extractive firms are responding to supply and demand shocks and argues that a paradigm shift may be necessary in which traditional bridging activities become part of protecting core business activities to ameliorate the risk of losing a firm’s social license to operate.
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Moleko-Boyce, Pulleng, Hlamulo Makelane, Mbokazi Z. Ngayeka, and Zenixole R. Tshentu. "Recovery of Platinum Group Metals from Leach Solutions of Spent Catalytic Converters Using Custom-Made Resins." Minerals 12, no. 3 (March 16, 2022): 361. http://dx.doi.org/10.3390/min12030361.
Abstract:
Platinum group metals (PGMs) play a key role in modern society as they find application in clean technologies and other high-tech equipment. Spent catalytic converters as a secondary resource contain higher PGM concentrations and the recovery of these metals via leaching is continuously being improved but efforts are also directed at the purification of individual metal ions. The study presents the recovery of PGMs, namely, rhodium (Rh), platinum (Pt) and palladium (Pd) as well as base metals, namely, zinc (Zn), nickel (Ni), iron (Fe), manganese (Mn) and chromium (Cr) using leachates from spent diesel and petrol catalytic converters. The largest amount of Pt was leached from the diesel catalytic converter while the petrol gave the highest amount of Pd when leached with aqua regia. Merrifield beads (M) were functionalized with triethylenetetramine (TETA), ethane-1,2-dithiol (SS) and bis((1H-benzimidazol-2-yl)methyl)sulfide (NSN) to form M-TETA, M-SS and M-NSN, respectively, for recovery of PGMs and base metals from the leach solutions. The adsorption and loading capacities of the PGMs and base metals were investigated using column studies at 1 M HCl concentration. The loading capacity was observed in the increasing order of Pd to be 64.93 mmol/g (M-SS), 177.07 mmol/g (M-NSN), and 192.0 mmol/g (M-TETA), respectively, from a petrol catalytic converter. The M-NSN beads also had a much higher loading capacity for Fe (489.55 mmol/g) compared to other base metals. The finding showed that functionalized Merrifield resins were effective for the simultaneous recovery of PGMs and base metals from spent catalytic converters.
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Larson, Michelle S., William E. Stone, William A. Morris, and James H. Crocket. "Magnetic signature of magnetite‐enriched rocks hosting platinum‐group element mineralization within the Archean Boston Creek Flow, Ontario." GEOPHYSICS 63, no. 2 (March 1998): 440–45. http://dx.doi.org/10.1190/1.1444344.
Abstract:
Ground‐based magnetometer surveys detect high‐positive magnetic anomalies (up to 72 000 nT) which coincide with the location of subeconomic, magnetite‐associated platinum‐group element (PGE) mineralization within the Boston Creek Flow iron‐rich basalt, Archean Abitibi Greenstone Belt, Ontario. The magnetic anomalies confirm the presence of magnetite‐enriched zones (up to 20 modal%), and reveal that they are ovoid in shape, up to 10 m in size, and along strike from each other in the central gabbro‐diorite layer. Geological and geochemical surveys and mineralogical studies indicate that these zones host smaller zones of disseminated chalcopyrite + pyrite, some of which, in turn, host platinum‐group minerals (PGM) and are enriched in PGE and related metals (whole‐rock [Formula: see text], Ag = 1300 ppb, Cu = 0.3%, V = 0.1%, Ni = 0.05%, Ti = 2.5%, and Fe = 25%). The coincidence of the high‐positive magnetic anomalies with the location of PGE mineralization, points to ground‐based magnetometer surveys as a valuable exploration tool for magnetite‐associated PGE ore deposits. The distribution of the residual magnetic field anomalies indicate that such surveys are especially useful in: (1) identifying rock types and mapping their distribution in areas of limited outcrop exposure; (2) locating magnetite‐enriched gabbroic rock bodies, even in close proximity to serpentinized olivine cumulate rocks; and (3) delineating the detailed geometry of magnetite‐enriched rocks that may carry significant amounts of PGE and PGMs. Exploration strategies should be designed to use ground‐based geophysical surveys, in conjunction with geological and geochemical surveys, to locate and delineate the geometry of magnetite‐enriched zones within thick, differentiated mafic‐ultramafic volcanic flows and plutonic bodies.