Zeitschriftenartikel: „Platinum metal“

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Dey, Sandip, und Vimal K. Jain. „Platinum Group Metal Chalcogenides“. Platinum Metals Review 48, Nr. 1 (01.01.2004): 16–29. http://dx.doi.org/10.1595/003214004x4811629.

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Some salientfeatures of platinum group metal compounds with sulfur, selenium or tellurium, known as chalcogenides, primarily focusing on binary compounds, are described here. Their structural patterns are rationalised in terms of common structural systems. Some applications of these compounds in catalysis and materials science are described, and emerging trends in designing molecular precursors for the syntheses of these materials are highlighted.

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Thompson, D. T. „Platinum Group Metal Fullerenes“. Platinum Metals Review 40, Nr. 1 (01.01.1996): 23–25. http://dx.doi.org/10.1595/003214096x4012325.

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3

Zhang, Ruiquan, Zhou Zhang, Qing Chen, Maocong Hu und Zhenhua Yao. „Revolutionizing Fuel Cell Efficiency with Non-Metallic Catalysts for Oxygen Reduction Reactions“. Global Environmental Engineers 9 (25.12.2022): 49–59. http://dx.doi.org/10.15377/2410-3624.2022.09.4.

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Platinum-based catalysts are widely used in oxygen reduction reactions, but platinum’s high cost and low reserves have restricted their sustainable development. With continuous in-depth research, it has been found that metal-free catalysts also have better catalytic activity in oxygen reduction reactions and have great potential for development due to the low cost and abundant reserves of metal-free catalysts, which has become a hot research direction. This paper reviews the application of metal-free catalysts in oxygen reduction reactions, including heteroatom-doped carbon-based catalysts, polymeric nitrogen catalysts, and emerging carbon catalysts. This work provides insights into developing non-platinum catalysts for oxygen reduction reactions by comparing the catalytic activity, selectivity, and prolonged stability.

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M.I.D. „Platinum Group Metal Coatings for Metal Hydrides“. Platinum Metals Review 34, Nr. 3 (01.07.1990): 142–43. http://dx.doi.org/10.1595/003214090x343142143.

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5

Uruga, Kazuyoshi, Kayo Sawada, Youichi Enokida und Ichiro Yamamoto. „ICONE15-10605 INFLUENCE OF THE SIZE OF COLLECTING METAL ON REMOVAL OF PLATINUM GROUP METALS FROM MOLTEN GLASS“. Proceedings of the International Conference on Nuclear Engineering (ICONE) 2007.15 (2007): _ICONE1510. http://dx.doi.org/10.1299/jsmeicone.2007.15._icone1510_329.

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6

Al-Allaf, Talal A. K., und Abeer Z. M. Sheet. „Platinum group metal Schiff base complexes—I. Platinum complexes“. Polyhedron 14, Nr. 2 (Januar 1995): 239–48. http://dx.doi.org/10.1016/0277-5387(94)00231-3.

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7

Edwards, C. „Metal Gurus [Materials science - platinum]“. Engineering & Technology 17, Nr. 5 (01.06.2022): 26–9. http://dx.doi.org/10.1049/et.2022.0510.

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8

Screen, By Thomas. „Platinum Group Metal Perovskite Catalysts“. Platinum Metals Review 51, Nr. 2 (01.04.2007): 87–92. http://dx.doi.org/10.1595/147106707x192645.

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9

Cheng, Kang, Luc C. J. Smulders, Lars I. van der Wal, Jogchum Oenema, Johannes D. Meeldijk, Nienke L. Visser, Glenn Sunley et al. „Maximizing noble metal utilization in solid catalysts by control of nanoparticle location“. Science 377, Nr. 6602 (08.07.2022): 204–8. http://dx.doi.org/10.1126/science.abn8289.

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Maximizing the utilization of noble metals is crucial for applications such as catalysis. We found that the minimum loading of platinum for optimal performance in the hydroconversion of n -alkanes for industrially relevant bifunctional catalysts could be reduced by a factor of 10 or more through the rational arranging of functional sites at the nanoscale. Intentionally depositing traces of platinum nanoparticles on the alumina binder or the outer surface of zeolite crystals, instead of inside the zeolite crystals, enhanced isomer selectivity without compromising activity. Separation between platinum and zeolite acid sites preserved the metal and acid functions by limiting micropore blockage by metal clusters and enhancing access to metal sites. Reduced platinum nanoparticles were more active than platinum single atoms strongly bonded to the alumina binder.

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Takase, Yoshiaki, Sachiko Nakano, Ei Yamaki und Osamu Kawashima. „Pulmonary arteriovenous malformation with metal allergy“. BMJ Case Reports 14, Nr. 3 (März 2021): e240275. http://dx.doi.org/10.1136/bcr-2020-240275.

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We present a rare case of single pulmonary arteriovenous malformation (PAVM) with multiple metal allergies, including for platinum. A 47-year-old woman presented to our hospital without any symptoms. Enhanced computed tomography showed a single PAVM in S6 of the right lung. Interviews prompted us to suspect a history of palmoplantar pustulosis associated with metal dental filling. Dermatology patch tests for metal allergy were positive for platinum, cobalt, tin and potassium dichromate. The first choice of treatment for PAVM is endovascular treatment using a metal coil. Since the coil is composed of platinum alloy, we performed partial lung resection for PAVM without metal implants. Although metal allergy is rare for endovascular treatment, it causes an additional stress of removal of causative metal or long-term steroidal treatment. Therefore, for single PAVM with multiple metal allergies to the implants, surgical treatment without metal implants should be considered.

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Pradesar, Yusuf, Afandi Yusuf, Daniel Manaye Kabtamu, Chen-Hao Wang und Hsin-Chih Huang. „Metal−Organic Framework CPO-27 Derivatives As Non-Precious Metal Catalyst for Anion Exchange Membrane Fuel Cell“. ECS Meeting Abstracts MA2023-02, Nr. 49 (22.12.2023): 3257. http://dx.doi.org/10.1149/ma2023-02493257mtgabs.

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Fuel cell stands as an environmentally friendly technology harnessing the power of hydrogen to generate clean water. In the range of fuel cell types, the anion exchange membrane fuel cell (AEMFC) stands out, effectively converting chemical energy to electricity without relying on platinum catalyst. Nonetheless, platinum catalyst is still used in addressing the sluggishness of the oxygen reduction reaction (ORR) during AEMFC operation. The scarcity and expense of platinum, however, hinder its widespread adoption. Furthermore, in the alkaline environment, platinum surface is covered with OH species, impeding active sites and diminishing electrochemical activity. Consequently, seeking an efficient, stable, and abundant platinum substitute is a primary target in the development of fuel cell. This study focuses on the development of the non-precious metal catalyst for the ORR in AEMFC. The catalyst, denoted as NiCo2-CPO-27/PCN, is derived from a carbon nanorod structure obtained from the metal-organic framework (CPO-27). Through the optimized process, the catalyst demonstrates the distinct carbon nanorod configuration. Additionally, the NiCo2-CPO-27/PCN catalyst exhibits enhanced ORR activity, achieving the electron transfer number of 3.99, which closely approaches the ideal four-electron transfer number. This improvement in activity is attributed to factors such as the specific structure, heteroatom contribution, and coordination arrangement of the catalyst.

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Kuznetsov, S. V., M. V. Korobov, L. N. Sidorov, L. N. Savinova, V. A. Shipachev und V. N. Mit'kin. „Gas-phase negative ions of platinum metal fluorides. I. Electron affinity of platinum metal tetrafluorides“. International Journal of Mass Spectrometry and Ion Processes 87, Nr. 1 (Januar 1989): 1–11. http://dx.doi.org/10.1016/0168-1176(89)80001-1.

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Korobov, M. V., S. V. Kuznetsov, L. N. Sidorov, V. A. Shipachev und V. N. Mit'kin. „Gas-phase negative ions of platinum metal fluorides. II. Electron affinity of platinum metal hexafluorides“. International Journal of Mass Spectrometry and Ion Processes 87, Nr. 1 (Januar 1989): 13–27. http://dx.doi.org/10.1016/0168-1176(89)80002-3.

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14

Maulana, Ilham Maulana Ilham, Peter Loennecke Peter Loennecke und Evamarie Hey-Hawkins Evamarie Hawkins. „Platinum Metal Complexes of Carbaboranylphophines: Potential Anti Cancer Agents“. Indonesian Journal of Cancer Chemoprevention 1, Nr. 1 (28.02.2010): 1. http://dx.doi.org/10.14499/indonesianjcanchemoprev1iss1pp1-11.

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Polyhedral heteroboranes in particular dicarba-closo-dodecaboranes(12) and their organic derivatives have been the subject of intense research for over 40 years due to their unique chemical and physical properties. The initial attraction to dicarba-closo-dodecaboranes(12) In the medicinal chemistry research, was a result of their high boron content and stability to catabolism, which are important criteria for cancer therapy, such as BNCT (boron neutron capture therapy) agents. The coordination compounds of the platinum group metals have also received large interest for their potential application as chemotherapeutic agents, since cis-diamminedichloroplatinum(II), cisplatin, has been reported to have capability as tumor inhibitor. Hence, applications can be envisioned for related cis platinum complexes. Complex of cis-rac-[PtCl2{1,2-(PRCl)2C2B10H10}] (R=Ph, tBu, NEt2, NPh2) have been synthesized by employing known carbaborane based phosphine ligands of clorophoshino-closo-dodecaborane , with complex of cis-[PtCl2(COD)] (COD = 1,5-cyclooctadiene) in an N2-atmosphere. The obtained complexes possess expected structure configuration, namely cis-rac. The characterization of the complex has been carried out using 1H, 31P, 13C and 11B-NMR (Nuclear Magnetic Resonance), X-ray of single crystals, elemental analysis, IR (infra red) and mass spectroscopy (MS). The 31P{1H} NMR spectra of all the platinum complexes distinctly show the typical platinum satellites which are attributed to 31P-195Pt-coupling, in which the 31P{1H} NMR spectrum exhibits three lines with an intensity ratio of ca.1:4:1. The structure of the platinum complexes consists of a slightly distorted square-planar coordination sphere, in which the platinum atom is bonded to two chlorides and two phosphorus atoms of the chelating carbaboranylphosphine. Thus the platinum atoms exhibit the coordination number four, which is preferred in platinum(II) complexes.Keywords: Platinum complexes, phosphine ligand, carbaborane

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Hubicki, Zbigniew, Karolina Zinkowska und Grzegorz Wójcik. „A New Impregnated Adsorbent for Noble Metal Ion Sorption“. Molecules 28, Nr. 16 (13.08.2023): 6040. http://dx.doi.org/10.3390/molecules28166040.

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Noble metals (NM) such as gold, platinum, palladium, and rhodium are widely applied in the electronics and automotive industries. Thus, the search for cheap and selective sorbents for noble metals is economically justified. Nitrolite does not sorb noble metal ions. A new impregnated sorbent was prepared. The natural sorbent Nitrolite was impregnated with Aliquat 336 using a new warm impregnation method. After the impregnation process, Nitrolite adsorbed platinum(IV), palladium(II), and gold(III) ions from the chloride solutions. The values of the sorption capacity for palladium(II) and platinum(IV) ions were 47.63 mg/g and 51.39 mg/g, respectively, from the 0.1 M HCl model solution. The sorption capacity for gold(III) ions was estimated to be 73.43 mg/g from the 0.1 M HCl model solution. An exhausted catalytic converter was leached, and platinum(IV), palladium(II), and rhodium(III) were transferred to the chloride solution. The impregnated sorbent Nitrolite–Aliquat 336 was used in the investigations of the platinum(IV), palladium(II), and rhodium(III) ions’ sorption from a real solution. The impregnated sorbent Nitrolite–Aliquat 336 proved to be suitable for the recovery of platinum(IV) and palladium(II) ions, whereas rhodium ions were not sorbed from the leached solutions. Notably, 1 M thiourea in the 1 M HCl solution desorbed platinum(IV), palladium(II), and gold(III) above 94%.

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McGill, I. R. „Some Ternary and Higher Order Platinum Group Metal Alloys“. Platinum Metals Review 31, Nr. 2 (01.04.1987): 74–90. http://dx.doi.org/10.1595/003214087x3127490.

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Platinum-based alloys find many applications in both high and low temperature industrial environments and are particularly suited to operation under corrosive aqueous and high temperature gaseous conditions. A wide variety of alloys exist which have been specifically designed for these purposes and in many cases they contain one or more non-platinum group metal. Although this situation is quite acceptable, there remains a fundamental need for systematic investigation of the basic properties and constitution of platinum group metal alloys. Such a foundation in materials technology generally leads to an understanding of materials behaviour and provides guidance in designing new alloys with improved properties for existing and future applications. This review features the work which has been done on ternary and higher order platinum group metal alloys and provides access to important data.

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Septiadi, Dedy, Alessandro Aliprandi, Matteo Mauro und Luisa De Cola. „Bio-imaging with neutral luminescent Pt(ii) complexes showing metal⋯metal interactions“. RSC Adv. 4, Nr. 49 (2014): 25709–18. http://dx.doi.org/10.1039/c4ra02351j.

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Burpo, Fred J., Alexander N. Mitropoulos, Enoch A. Nagelli, Madeline Y. Ryu und Jesse L. Palmer. „Gelatin biotemplated platinum aerogels“. MRS Advances 3, Nr. 47-48 (2018): 2875–80. http://dx.doi.org/10.1557/adv.2018.489.

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ABSTRACTHere gelatin biotemplated platinum aerogels were prepared from gelatin hydrogels equilibrated in K2PtCl4solutions ranging from 1-250 mM and reduced with sodium borohydride before supercritical drying in liquid CO2. Scanning electron microscopy revealed an average ligament diameter of 40.6 ± 9.7 nm and a pore size range of ∼10 – 200 nm. Thermogravimetric analysis correlated the ratio of metal content to biotemplate mass as a function of equilibrated platinum ion solution, and X-ray diffractometry indicated platinum metal with no detectable oxide phases. Electrochemical impedance spectroscopy indicated a specific capacitance of 1.92 F/g, with a corresponding specific electrochemical accessible surface area of 6.39 m2/g. Cyclic voltammetry performed in H2SO4demonstrated biotemplated platinum aerogel potential for catalytic and energy storage applications.

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Tang, Hailian, Yang Su, Yalin Guo, Leilei Zhang, Tianbo Li, Ketao Zang, Fei Liu et al. „Oxidative strong metal–support interactions (OMSI) of supported platinum-group metal catalysts“. Chemical Science 9, Nr. 32 (2018): 6679–84. http://dx.doi.org/10.1039/c8sc01392f.

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Mansur, Eduardo, Sarah-Jane Barnes und Cesar F. Ferreira Filho. „The effects of post-cumulus alteration on the distribution of chalcophile elements in magmatic sulfide deposits and implications for the formation of low-S-high-PGE zones: The Luanga deposit, Carajás Mineral Province, Brazil“. Canadian Mineralogist 59, Nr. 6 (01.11.2021): 1453–84. http://dx.doi.org/10.3749/canmin.2100018.

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ABSTRACT Most of the World's platinum-group element ore deposits occur as thin stratiform layers within layered intrusions. These layers generally contain disseminated base-metal sulfides or chromite. However, cryptic platinum-group element deposits also occur without chromite or base-metal sulfides in what are known as low-S-high platinum-group element deposits. The origin of these deposits is not clearly understood. The Luanga Complex hosts the largest platinum-group elements resource in South America (i.e., 142 Mt at 1.24 ppm Pt + Pd + Au and 0.11% Ni) and hosts both a platinum-group element deposit containing disseminated base-metal sulfides (style 1) and a low-S-high platinum-group element deposit (style 2). It therefore offers the opportunity to compare the two deposit types in the same overall geological setting and consider how the low-S-high platinum-group element deposit could have formed. The first deposit style is termed the Sulfide zone and consists of a 10–50 meter-thick interval with disseminated base metal sulfides, whereas the second style is named low-S-high-Pt-Pd zone and consists of 2–10 meter-thick discontinuous lenses of 1–5 meter-thick sulfide- and oxide-free harzburgite and orthopyroxenite with discrete platinum-group minerals. Secondary assemblages commonly replace primary igneous minerals to a variable extent throughout the deposit, and thus allow for investigating the effects of post-cumulus alteration on the distribution of a wide range of chalcophile elements in a magmatic sulfide deposit at both whole-rock and mineral scale. This study presents the whole-rock distribution of S, platinum-group elements, and Te, As, Bi, Sb, and Se in both mineralization styles and the concentration of trace elements in base-metal sulfides from the Sulfide zone. The Sulfide zone has Pt/Pd ratios around 0.5 and high concentrations of Te, As, Bi, Sb, and Se, whereas the low-S-high-platinum-group element zone has Pt/Pd ratios greater than 1 and much lower Se, Te, and Bi concentrations, but comparable As and Sb contents. This is reflected in the platinum-group element assemblage, comprising bismuthotellurides in the Sulfide zone and mostly arsenides and antimonides in the low-S, high platinum-group elements zone. Moreover, the base-metal sulfides from the Sulfide zone have anomalously high As contents (50–500 ppm), which suggest that the sulfide liquid segregated from a very As-rich silicate magma, possibly illustrated by an average komatiitic basalt that assimilated a mixture of upper continental crust and black shales. We interpret the low-S-high platinum-group elements zone as a product of S loss from magmatic sulfides during post-cumulus alteration of the Luanga Complex. Selenium, Te, Bi, and Pd were also lost together with S, whereas As and Sb were expelled from base-metal sulfide structures and combined with platinum-group elements to form platinum-group minerals, suggesting they may play a role fixating platinum-group elements during alteration. The remobilization of chalcophile elements from magmatic sulfide deposits located in the Carajás Mineral Province may represent a potential source for hydrothermal deposits found in the region.

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Merkle, Roland K. W. „Platinum-group minerals in the middle group of chromitite layers at Marikana, western Bushveld Complex: indications for collection mechanisms and postmagmatic modification“. Canadian Journal of Earth Sciences 29, Nr. 2 (01.02.1992): 209–21. http://dx.doi.org/10.1139/e92-020.

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The platinum-group minerals in a drill core taken through the middle group of chromitite layers in the Critical Zone at Marikana in the western Bushveld Complex were found to consist mainly of laurite as inclusions in chromite grains. The platinum-group minerals containing Pt, Pd, and Rh are concentrated in the intercumulus silicates and frequently associated with base-metal sulphides. Up to about 20% of all platinum-group minerals in the investigated chromitite layers contain sub stantial amounts of As. The base-metal sulphides are strongly modified in the postmagmatic stage, which led to a significant loss of Fe and S, in this way concentrating Cu, Ni, and the platinum-group elements by factors of up to 10. Interaction between chromite and base-metal sulphides cannot account for all the Fe lost in chromite-poor samples, and the importance of additional processes is indicated. Inclusions in chromite and orthopyroxene indicate the formation of discrete platinum-group minerals and As-rich phases before the formation of an immiscible sulphide melt. Resorption of earlier formed platinum-group minerals into the immiscible sulphide melt and postmagmatic sulphidation destroyed most of the evidence of the early formed platinum-group minerals.

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Leung, Sammual Yu-Lut, Keith Man-Chung Wong und Vivian Wing-Wah Yam. „Self-assembly of alkynylplatinum(II) terpyridine amphiphiles into nanostructures via steric control and metal–metal interactions“. Proceedings of the National Academy of Sciences 113, Nr. 11 (01.03.2016): 2845–50. http://dx.doi.org/10.1073/pnas.1601673113.

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A series of mono- and dinuclear alkynylplatinum(II) terpyridine complexes containing the hydrophilic oligo(para-phenylene ethynylene) with two 3,6,9-trioxadec-1-yloxy chains was designed and synthesized. The mononuclear alkynylplatinum(II) terpyridine complex was found to display a very strong tendency toward the formation of supramolecular structures. Interestingly, additional end-capping with another platinum(II) terpyridine moiety of various steric bulk at the terminal alkyne would lead to the formation of nanotubes or helical ribbons. These desirable nanostructures were found to be governed by the steric bulk on the platinum(II) terpyridine moieties, which modulates the directional metal−metal interactions and controls the formation of nanotubes or helical ribbons. Detailed analysis of temperature-dependent UV-visible absorption spectra of the nanostructured tubular aggregates also provided insights into the assembly mechanism and showed the role of metal−metal interactions in the cooperative supramolecular polymerization of the amphiphilic platinum(II) complexes.

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Frolov, V. M. „Platinum Metals Complex Catalysts for Liquid-Phase Hydrogenations“. Platinum Metals Review 40, Nr. 1 (01.01.1996): 8–18. http://dx.doi.org/10.1595/003214096x401818.

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Results of the syntheses and applications of platinum metals complex catalysts, which are uniquely active for the liquid-phase hydrogenation of unsaturated organic compounds, such as olefins, dienes, acetylenes and aromatics, are described. The platinum metals complex catalysts are synthesised by the interaction between platinum metals compounds and aliphatic amines with sufficiently long alkyl groups (C8 and higher). Similarities are shown in the production of palladium-, platinum-, and rhodium-based catalysts, which involves the formation of hydride ligands, using the hydrogen atoms of the alkyl groups, and the specific catalytic behaviour of each metal is described. Examples of synergistic effects for these platinum group metal catalysts and some of their related systems are discussed.

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Sharma, Mukta, Y. Kumar, S. Chandra und R. P. Singh. „Platinum Metal Complexes of Salicyladehyde Semicarbazone“. Synthesis and Reactivity in Inorganic and Metal-Organic Chemistry 15, Nr. 4 (Januar 1985): 471–78. http://dx.doi.org/10.1080/00945718508061414.

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SHIRAI, Masayuki. „Platinum Metal Nanosheets between Graphite Layers“. Kobunshi 52, Nr. 12 (2003): 904. http://dx.doi.org/10.1295/kobunshi.52.904.

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Pringle, P. G., und M. B. Smith. „Tris (hydroxymethyl) phosphine Platinum Metal Complexes“. Platinum Metals Review 34, Nr. 2 (01.04.1990): 74–76. http://dx.doi.org/10.1595/003214090x3427476.

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L.G.-F. „The Published Platinum Metal Alloy Systems“. Platinum Metals Review 39, Nr. 1 (01.01.1995): 18. http://dx.doi.org/10.1595/003214095x3911818.

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Kendall, Tom. „The London Platinum and Palladium Market“. Platinum Metals Review 48, Nr. 1 (01.01.2004): 13–14. http://dx.doi.org/10.1595/003214004x4811314.

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The London Platinum and Palladium Market (LPPM) oversees dealings in platinum and palladium. Twice each day, four members of the LPPM fix the bid prices. The bid price is the price at which LPPM members agree they will buy “good delivery” metal. The bid prices are benchmarks for the market and hence for the industry. Bid prices in turn affect the offer prices that customers are asked to pay for metal. The market values of platinum and palladium, as is the case for all commodities, ultimately affect manufacturing costs. Here, the background to the establishment of the LPPM is summarised and its current role in this important metal market is briefly described.

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van Hoogstraten, Sanne, Steven Samijo, Jan Geurts und Chris Arts. „NOBLE METAL-BASED ANTIBACTERIAL IMPLANT COATINGS FOR ARTICULATING IMPLANT SURFACES“. Orthopaedic Proceedings 105-B, SUPP_17 (24.11.2023): 30. http://dx.doi.org/10.1302/1358-992x.2023.17.030.

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AimProsthetic joint infections pose a major clinical challenge. Developing novel material surface technologies for orthopedic implants that prevent bacterial adhesion and biofilm formation is essential. Antimicrobial coatings applicable to articulating implant surfaces are limited, due to the articulation mechanics inducing wear, coating degradation, and toxic particle release. Noble metals are known for their antimicrobial activity and high mechanical strength and could be a viable coating alternative for orthopaedic implants [1]. In this study, the potential of thin platinum-based metal alloy coatings was developed, characterized, and tested on cytotoxicity and antibacterial properties.MethodThree platinum-based metal alloy coatings were sputter-coated on medical-grade polished titanium discs. The coatings were characterized using optical topography and scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS). Ion release was measured using inductively coupled plasma optical emission spectrometry (ICP-OES). Cytotoxicity was tested according to ISO10993-5 using mouse fibroblasts (cell lines L929 and 3T3). Antibacterial surface activity, bacterial adhesion, bacterial proliferation, and biofilm formation were tested with gram-positive Staphylococcus aureus ATCC 25923 and gram-negative Escherichia coli ATCC 25922. Colony forming unit (CFU) counts, live-dead fluorescence staining, and SEM-EDS images were used to assess antibacterial activity.ResultsThree different platinum-based metal alloys consisting of platinum-iridium, platinum-copper, and platinum-zirconium. The coatings were found 80 nm thick, smooth (roughness average < 60 nm), and non-toxic. The platinum-copper coating showed a CFU reduction larger than one logarithm in adherent bacteria compared to uncoated titanium. The other coatings showed a smaller reduction. This data was confirmed by SEM and live-dead fluorescence images, and accordingly, ICP-OES measurements showed low levels of metal ion release from the coatings.ConclusionsThe platinum-copper coating showed low anti-adhesion properties, even with extremely low metal ions released. These platinum-based metal alloy coatings cannot be classified as antimicrobial yet. Further optimization of the coating composition to induce a higher ion release based on the galvanic principle is required and copper looks most promising as the antimicrobial compound of choice.AcknowledgmentsThis publication is supported by the DARTBAC project (with project number NWA.1292.19.354) of the research program NWA-ORC which is (partly) financed by the Dutch Research Council (NWO); and the AMBITION project (with project number NSP20–1-302), co-funded by the PPP Allowance made available by Health-Holland, Top Sector Life Sciences & Health to ReumaNederland.

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Mills, A., und S. K. Lee. „Platinum Group Metals and their Oxides in Semiconductor Photosensitisation“. Platinum Metals Review 47, Nr. 1 (01.01.2003): 2–12. http://dx.doi.org/10.1595/003214003x471212.

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The basic principles of semiconductor photochemistry, particularly using titania as a semiconductor photocatalyst, are discussed. When a platinum group metal or its oxide is deposited onto the surface of a sensitised semiconductor the overall efficiency of the reactions it takes part in are often improved, especially when the deposits are used as hydrogen and oxygen catalysts, respectively. Methods of depositing metal or metal oxide are examined, and a particular focus is given to a photodeposition process that uses a sacrificial electron donor. Platinum group metal and platinum group metal oxide coated semiconductor photocatalysts are prominent in heterogeneous systems that are capable of the photoreduction, oxidation and cleavage of water. There is a recent renaissance in work on water-splitting semiconductor-sensitised photosystems, but there are continued concerns over their irreproducibility, longevity and photosynthetic nature.

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Baraka, A., H. H. Shaarawy und H. A. Hamed. „Electrodeposition of Platinum Metal and Platinum-Rhodium Alloy on Titanium Substrates“. Journal of Materials Engineering and Performance 12, Nr. 1 (01.02.2003): 5–13. http://dx.doi.org/10.1361/105994903770343402.

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Aggas, John R., William Harrell, Jodie Lutkenhaus und Anthony Guiseppi-Elie. „Metal–polymer interface influences apparent electrical properties of nano-structured polyaniline films“. Nanoscale 10, Nr. 2 (2018): 672–82. http://dx.doi.org/10.1039/c7nr06503e.

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The interface between the conductive polymer, polyaniline (PAn-Cl), and gold, platinum, or an interceding layer of electrodeposited platinum on gold or platinum, markedly influences the apparent electrical properties and the electronic to ionic transition in physiological buffers.

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Hayfield, P. C. S. „Development of the Noble Metal/Oxide Coated Titanium Electrode“. Platinum Metals Review 42, Nr. 2 (01.04.1998): 46–55. http://dx.doi.org/10.1595/003214098x4224655.

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In the first part of this paper, published in the January issue, development work resulting in the first noble metal/oxide coated titanium electrode was described and some of the teething problems encountered were discussed. Here, the story is continued with the further development of paint compositions: platinum-only and platinum/iridium, for coating the electrodes, and their utilisation in chlorate, mercury- and diaphragm-type chlor-alkali cells. Later, these coatings were replaced by ones containing ruthenium dioxide. This part begins with the early platinum paint compositions.

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Bucher, Jean Pierre, J. J. Van der Klink und M. Graetzel. „Platinum-195 NMR study of platinum/titania and platinum/silica catalysts: strong metal-support interaction“. Journal of Physical Chemistry 94, Nr. 4 (Februar 1990): 1209–11. http://dx.doi.org/10.1021/j100367a002.

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35

Mack, C. L., B. Wilhelmi, J. R. Duncan und J. E. Burgess. „Biosorptive recovery of platinum from platinum group metal refining wastewaters by immobilised Saccharomyces cerevisiae“. Water Science and Technology 63, Nr. 1 (01.01.2011): 149–55. http://dx.doi.org/10.2166/wst.2011.025.

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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.

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Mateos, Helena, Rosaria A. Picca, Antonia Mallardi, Marcella Dell’Aglio, Alessandro De Giacomo, Nicola Cioffi und Gerardo Palazzo. „Effect of the Surface Chemical Composition and of Added Metal Cation Concentration on the Stability of Metal Nanoparticles Synthesized by Pulsed Laser Ablation in Water“. Applied Sciences 10, Nr. 12 (17.06.2020): 4169. http://dx.doi.org/10.3390/app10124169.

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Metal nanoparticles (NPs) made of gold, silver, and platinum have been synthesized by means of pulsed laser ablation in liquid aqueous solution. Independently from the metal nature, all NPs have an average diameter of 10 ± 5 nm. The ζ-potential values are: −62 ± 7 mV for gold, −44 ± 2 mV for silver and −58 ± 3 for platinum. XPS analysis demonstrates the absence of metal oxides in the case of gold and silver NPs. In the case of platinum NPs, 22% of the particle surface is ascribed to platinum oxidized species. This points to a marginal role of the metal oxides in building the negative charge that stabilizes these colloidal suspensions. The investigation of the colloidal stability of gold NPs in the presence of metal cations shows these NPs can be destabilized by trace amounts of selected metal ions. The case of Ag+ is paradigmatic since it is able to reduce the NP ζ-potential and to induce coagulation at concentrations as low as 3 μM, while in the case of K+ the critical coagulation concentration is around 8 mM. It is proposed that such a huge difference in destabilization power between monovalent cations can be accounted for by the difference in the reduction potential.

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Cheng, Heung-Kiu, und Vivian Wing-Wah Yam. „Luminescent alkynylplatinum(II) terpyridine-containing conjugated polymers: synthesis, characterization and photophysical studies“. Chemical Synthesis 3, Nr. 2 (2023): 13. http://dx.doi.org/10.20517/cs.2022.43.

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A series of alkynylplatinum(II) terpyridine complexes and alkynylplatinum(II) terpyridine-containing conjugated polymers with different polymer backbones has been synthesized, and their spectroscopic properties and Förster resonance energy transfer (FRET) processes has been investigated. The platinum(II)-containing polymers exhibit dual emissive features with emission maxima at ca. 416-465 nm and ca. 671-673 nm, which are assigned to be originated from singlet intraligand (1IL) excited states from the polymer backbone and triplet metal-metal-to-ligand charge transfer (3MMLCT) excited states from the platinum(II) pendants, respectively. The Förster radii (R0) of the platinum(II)-containing conjugated polymers have been determined, and their distinctive thermo-responsive luminescence changes have also been observed. The present work has demonstrated the utilization of “click” reaction for the preparation of platinum(II)-containing conjugated polymers, which show unique photophysical and spectroscopic properties. Through the judicious design, this type of platinum(II)-containing polymer is found to be sensitive to temperature, resulting in ratiometric emission changes. This study has provided valuable insights into the preparation of metal-containing polymeric systems for different applications.

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Pokharel, Komal, Gregory M. Ferrence und Timothy D. Lash. „Late transition metal complexes of oxypyriporphyrin and the platinum(II) complex of oxybenziporphyrin“. Journal of Porphyrins and Phthalocyanines 21, Nr. 07n08 (Juli 2017): 493–501. http://dx.doi.org/10.1142/s1088424617500535.

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Even though oxypyriporphyrin, a pyridone-containing porphyrinoid system, has the equivalent coordination core to true porphyrins, its coordination chemistry has been little explored. In this study, the first examples of palladium(II), platinum(II) and silver(II) oxypyriporphyrins have been synthesized. Conventional conditions failed to result in the formation of a platinum(II) complex, but moderate yields were obtained when oxypyriporphyrin was reacted with platinum(II) chloride in refluxing mixtures of DMF and acetic acid containing potassium acetate. The palladium(II) and platinum(II) derivatives were characterized by X-ray crystallography. The structurally analogous carbaporphyrinoid system oxybenziporphyrin was also shown to react with platinum(II) chloride under the same conditions to give a platinum(II) hydroxybenziporphyrin complex. Unlike oxybenziporphyrin, this complex is only weakly diatropic. In the presence of base, the diatropic character was reasserted to afford an aromatic anionic species.

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Wei, Chengpeng, Mingyang Liu, Yifei Han, Hua Zhong und Feng Wang. „Supramolecular Chirogenesis Engineered by Pt(II)···Pt(II) Metal–Metal Interactions“. Organic Materials 03, Nr. 02 (April 2021): 274–80. http://dx.doi.org/10.1055/a-1512-5965.

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Supramolecular chirogenesis represents an effective way to induce chirality at the supramolecular level. For the previous host–guest chirogenic systems, metal–ligand coordination, hydrogen bonding, π–π stacking and hydrophobic interactions have been mainly employed as the non-covalent driving forces. In this study, Pt(II)···Pt(II) metal–metal interactions have been engineered to induce supramolecular chirogenesis, by forming non-covalent clipping structures between chiral platinum receptors and achiral platinum guests together. This results in the emergence of Cotton effects in the metal–metal-to-ligand charge transfer region, ascribed to chirality transfer from trans-1,2-diamide cyclohexane unit on chiral receptors to Pt(II)---Pt(II) non-covalent interacting sites. Supramolecular chirogenesis can be further transferred from organic to aqueous solutions, with higher resistance to concentration and temperature variations in the latter medium. Overall, the current study provides new avenues toward supramolecular chirality systems with tailored properties.

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Zhang, Jingjing, Bing Li und Cunman Zhang. „(Digital Presentation) An Efficient and Stable of Low-Pt Catalysts for Full Water Splitting in Acidic“. ECS Meeting Abstracts MA2023-01, Nr. 36 (28.08.2023): 2120. http://dx.doi.org/10.1149/ma2023-01362120mtgabs.

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Designing efficient platinum-based catalysts is of great interest for the lowering of Pt dosage and the enhance of catalytic activity on the full water splitting. However, it is still challenging to develop low-Pt catalysts with evenly distributed, proper sized particles on supports. Here, Metal-Organic Frameworks (MOF) derivatives were used as supports to prepare ultra-low platinum catalysts of uniform particle size. MOF derived transition metal heteroatom-doped carbon is a promising support for precious metal nanoparticles of electrocatalytic activity, because it provides abundant anchor points that enhance their adhesion, transition metals on the MOF skeleton can effectively prevent further growth of platinum particles, more importantly, through the proof-metal electron interaction, improve their intrinsic catalytic activity to achieve high activity and stable hydrogen evolution reaction. We will characterize the characteristics of the catalyst from several aspects, such as morphology, pore size and composition. Finally, we will verify the catalytic ability, rate ability and stability of low platinum catalyst with MOF derivatives support, through a comprehensive characterization of the catalyst HER and OER performance.

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Ivanova, Stefka, Stefan Balkanski, Petar Atanasov, Maria Chaneva, Danka Obreshkova, Valentin Dimitrov, Krasimira Kazalukova, Lily Peikova und Ognian Markov. „Antitumor and antioxidant activity of some metal complex compounds“. Pharmacia 70, Nr. 2 (07.06.2023): 375–82. http://dx.doi.org/10.3897/pharmacia.70.e105845.

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In the last few years, interest in platinum drugs has increased. Successful treatment depends to a large extent on complex therapy and early diagnosis, which determines the great importance of knowledge of risk groups, clinical symptoms, and targeted use of diagnostic methods with biomarkers, biopsy and diagnostic imaging for early detection of the malignant process. Today, the mono-target strategy is being replaced by a poly-target therapy strategy, which achieves greater clinical efficacy in tumors with defined biomarkers. Key developments include elucidation of the mechanisms of tumor resistance to these drugs, the introduction of some new platinum- based agents and clinical combination studies using platinum drugs with resistance modulators or new drug-targeted drugs. Improved delivery of platinum drugs to tumors has been studied in early clinical trials using liposomal or copolymer-based products. Other investigated as anticancer agents are ruthenium and iron complexes. Ln(III) complexes have been shown to exert antioxidant activity.

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42

Ning, Yuantao, Zhengfen Yang und Huaizhi Zhao. „Platinum Recovery by Palladium Alloy Catchment Gauzes in Nitric Acid Plants“. Platinum Metals Review 40, Nr. 2 (01.04.1996): 80–87. http://dx.doi.org/10.1595/003214096x4028087.

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Since the introduction of palladium-gold catchment gauzes for the recovery of the platinum lost from the catalyst gauzes used in the manufacture of nitric acid, the mechanism by which these high palladium content alloys catch and recover the platinum has been of interest to both researchers and manufacturers, alike. Using analyses of the surface chemical species which form on palladium, both in flowing oxygen and during the ammonia oxidation reaction, this paper describes how the surface of the palladium, at temperatures above 800°C, is a multilayer structure with the bright palladium metal surface being covered by a thin layer of palladium metal vapour and then by a layer of palladium oxide vapour. The mechanism of the platinum recovery is related to the surface state of the palladium, and the high recovery rate by the palladium alloy catchment gauze is attributed to this unique multilayer structure and to the ability of palladium to reduce platinum oxide. Damage to either the surface multilayer structure or the oxidation characteristics of palladium decreases the platinum recovery rate. Thus, catchment gauzes made from palladium alloys containing high concentrations of base metal solutes, such as nickel, cannot be expected to have such a high platinum recovery rate.

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Stiegman, A. E., V. M. Miskowski und Harry B. Gray. „Metal-metal excited-state emission from binuclear platinum(III) complexes“. Journal of the American Chemical Society 108, Nr. 10 (Mai 1986): 2781–82. http://dx.doi.org/10.1021/ja00270a062.

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44

Berger, Josefine, Thomas Braun, Roy Herrmann und Beatrice Braun. „Reactivity of platinum alkyne complexes towards N-fluorobenzenesulfonimide: formation of platinum compounds bearing a β-fluorovinyl ligand“. Dalton Transactions 44, Nr. 45 (2015): 19553–65. http://dx.doi.org/10.1039/c5dt02306h.

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Wright, John C. „Jewellery-Related Properties Of Platinum“. Platinum Metals Review 46, Nr. 2 (01.04.2002): 66–72. http://dx.doi.org/10.1595/003214002x4626672.

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The performance of precious metal alloys can be usefully compared by the application of engineering design theory and heat flow properties on the small scale that is required for jewellery production. Some of the physical and mechanical properties of Platinum jewellery alloys differ sufficiently from typical gold and silver alloys to require modifications in the processing techniques, but these properties may allow for stronger slender designs. The thermal diffusivity of Platinum jewellery alloys is significantly lower than that of other precious metal jewellery alloys. This explains why laser welding is so efficient when used in making platinum jewellery and why it also allows most of the cold work hardening to be retained in components.

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Yan, Li, und Ji Shou Zhao. „Study Pressure-Cyanide Dissolution Different of Metal Palladium and Platinum Powder“. Advanced Materials Research 734-737 (August 2013): 2514–18. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.2514.

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s: A research study has been undertaken to develop the fundamentals of a method for the direct dissolution of platinum group metals (PGMs). At room temperature and pressures, the reaction between sodium cyanide and platinum group metals (PGMs) does not occur because of poor kinetics. However, at elevated temperatures between 120-180 °C, PGMs can be leached by sodium cyanide like the reaction of gold. In this work, the dissolution of Palladium and Platinum powder were measured in pressure clear cyanide solution. The cyanide leaching reaction mechanism is also discussed.The data at different cyanide concentrations, different temperature and different oxygen pressure are obtained. The dissolution rate off metal Palladium and Platinum powder were found to be a function of the cyanide and oxygen level.

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Tshabalala, Themba E., Neil J. Coville, James A. Anderson und Michael S. Scurrell. „Dehydroaromatization of methane over noble metal loaded Mo/H-ZSM-5 zeolite catalysts“. Applied Petrochemical Research 11, Nr. 2 (03.05.2021): 235–48. http://dx.doi.org/10.1007/s13203-021-00274-y.

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AbstractDehydroaromatization of methane (MDA) reaction was investigated over platinum modified Mo/H-ZSM-5 catalysts which were pre-carbided at 750 °C. The influence of platinum on the catalytic performance and product selectivity of Mo/H-ZSM-5 catalysts for the MDA reaction at 700 °C were studied. The presence of platinum led to a slight decrease in methane conversion from 7.5 to 4.2%. Aromatic selectivities above 90% were obtained with catalysts containing low platinum loadings (0.5 and 1.0 wt.%), with benzene being the most prominent product. A decrease in coke selectivity and coke deposits was noted with the platinum modified Mo/H-ZSM-5 zeolite catalysts. A comparative study was performed to compare platinum, palladium and ruthenium promoted Mo/H-ZSM-5 zeolite catalysts with un-promoted Mo/H-ZSM-5. The ruthenium promoted catalyst proved to be superior in catalytic performance, with a higher methane conversion obtained than that found for platinum promoted and palladium promoted Mo/H-ZSM-5 catalysts. Benzene selectivity of about 60% was obtained for ruthenium and palladium promoted Mo/H- ZSM-5 catalysts and the total aromatic selectivity was maintained at 90%. TGA results showed a total reduction of 50% by weight of carbon deposited on the promoted Mo/H-ZSM-5 catalyst. Graphic abstract

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Choi, Dae Keun, und Sang Hoon Lee. „Evaluation of Properties of FIB Deposited Metal Layer and Application to Temperature Sensing“. Applied Mechanics and Materials 319 (Mai 2013): 54–57. http://dx.doi.org/10.4028/www.scientific.net/amm.319.54.

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In this paper, the properties of Focused-Ion-Beam (FIB) deposited platinum layer are investigated using the MEMS processes. First, the electrical properties are examined with three parallel metal lines and the measurement result shows over one hundred times larger resistivity than that of the conventional platinum layer. This feature is due to the additional materials like carbon compound and the gallium ion. The thermal properties are also investigated about the temperature coefficient of resistivity (TCR). The measured TCR values are -0.0015~-0.0020 K-1 which are different from the positive TCR in conventional platinum layer. The carbon compound has negative TCR and changes the properties of FIB metal layer. Although some non-uniform properties are observed, the properties of FIB deposited platinum layer are sufficient for the temperature sensing applications at small area.

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Ivanova, Valentina, Mila Manolova und Dieter M. Kolb. „Palladium and Platinum Deposition onto 4-Mercaptopyridine SAMs“. Solid State Phenomena 121-123 (März 2007): 363–68. http://dx.doi.org/10.4028/www.scientific.net/ssp.121-123.363.

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A novel technique has recently been presented for depositing metal layers onto a SAM. This is demonstrated here for Pd and Pt deposits on a mercaptopyridine (4-PyS) SAM. The SAMcovered Au(111) electrode is immersed into the metal-ion-containing solution without potential control. As a result, metal ions, e.g., Pd(II) (respectively Pt(II)) adsorb on the surface by forming a complex with the pyridine species. Subsequently, the electrode is transferred to a metal-ion-free solution, where the adsorbed metal ions are reduced electrochemically to its zero-valent state. Upon reduction, monoatomic high metal islands were observed in STM. Angle resolved XPS measurements show unequivocally that the reduced metal resides on top of the SAM.

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Ruzicka, Jan-Yves, David P. Anderson, Sally Gaw und Vladimir B. Golovko. „Platinum-Ruthenium Nanoparticles: Active and Selective Catalysts for Hydrogenation of Phenylacetylene“. Australian Journal of Chemistry 65, Nr. 10 (2012): 1420. http://dx.doi.org/10.1071/ch12219.

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Bimetallic metal nanoparticles are often more catalytically active than their monometallic counterparts, due to a so-called ‘synergistic effect’. Atomically precise ruthenium-platinum clusters have been shown to be active in the hydrogenation of phenylacetylene to styrene (a reaction of importance to the polymer industry). However, the synthesis of these clusters is generally complex, and cannot be modified to produce clusters with differing metal compositions or ratios. Hence, any truly systematic study of compositional effects using such clusters is hindered by the inaccessibility of certain metal ratios. In this study, a series of larger bimetallic ruthenium-platinum colloids of varying metal ratios was synthesised in solution and immobilised on silica. Catalytic activity was evaluated by hydrogenation of phenylacetylene to styrene. Both bimetallic and monometallic colloids were active catalysts for the hydrogenation of phenylacetylene to styrene and further to ethylbenzene. Of those studied, a catalyst composed of 73 % platinum-27 % ruthenium (by moles) showed the highest activity. This suggests that synergistic effects play an important role in the catalysis of this reaction. To our knowledge this is the first systematic study of ruthenium-platinum nanoparticle catalytic activity on this reaction.

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