Survey of Methods of Refining Catalysts for the Extraction of Platinum Group Metals

2019 ◽  
Vol 946 ◽  
pp. 528-532
Author(s):  
E.A. Devyatykh ◽  
T.O. Devyatykh ◽  
A.N. Boyarsky
Keyword(s):  
Catalytic Activity ◽  
Chemical Reactions ◽  
Precious Metals ◽  
Platinum Group Metals ◽  
Significant Part ◽  
High Catalytic Activity ◽  
Important Condition ◽  
Special Position ◽  
Global Demand ◽  
Platinum Group

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.

Biorecovery of Platinum Group Metals from Secondary Sources

2007 ◽  
Vol 20-21 ◽  
pp. 651-654 ◽  
Author(s):  
Angela J. Murray ◽  
I.P. Mikheenko ◽  
Elzbieta Goralska ◽  
N.A. Rowson ◽  
Lynne E. Macaskie
Keyword(s):  
Catalytic Activity ◽  
Precious Metals ◽  
Bacterial Biomass ◽  
Platinum Group Metals ◽  
X Ray ◽  
Secondary Sources ◽  
Price Increases ◽  
Valuable Product ◽  
Platinum Group

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.

Templating of electrodeposited platinum group metals as a tool to control catalytic activity

2007 ◽  
Vol 52 (28) ◽  
pp. 7910-7919 ◽  
Author(s):  
K.S. Napolskii ◽  
P.J. Barczuk ◽  
S.Yu. Vassiliev ◽  
A.G. Veresov ◽  
G.A. Tsirlina ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Platinum Group Metals ◽  
Platinum Group

Effect of Different Iron Sources on In-Situ Growth of Zeolitic Imidazolate Frameworks-8: For Efficient Oxygen Reduction Electrocatalysts

2021 ◽  
Vol 21 (10) ◽  
pp. 5319-5328
Author(s):  
Sha-Sha Luo ◽  
Yu-Meng Ma ◽  
Peng-Wei Li ◽  
Ming-Hua Tian ◽  
Qiao-Xia Li
Keyword(s):  
Catalytic Activity ◽  
High Temperature ◽  
Oxygen Reduction ◽  
High Performance ◽  
Low Cost ◽  
Three Dimensional ◽  
Precious Metals ◽  
High Catalytic Activity ◽  
Zeolitic Imidazolate Frameworks ◽  
Wide Range

Transition metal and nitrogen co-doped carbon-based catalysts (TM-N-C) have become the most promising catalysts for Pt/C due to their wide range of sources, low cost, high catalytic activity, excellent stability and strong resistance to poisoning, especially Fe–N–C metal-organic frameworks (MOFs), which are some of the most promising precursors for the preparation of Fe–N–C catalysts due to their inherent properties, such as their highly ordered three-dimensional framework structure, controlled porosity, and tuneable chemistry. Based on these, in this paper, different iron sources were added to synthesis a sort of zeolitic imidazole frameworks (ZIF-8). Then the imidazole salt in ZIF-8 was rearranged into high N-doped carbon by high-temperature pyrolysis to prepare the Fe–N–C catalyst. We studied the physical characteristics of the catalysts by different iron sources and their effects on the catalytic properties of the oxygen reduction reaction (ORR). From the point of morphology, various iron sources have a positive influence on maintaining the morphology of ZIF-8 polyhedron. Fe–N/C–Fe(NO3)3 has the same anion as zinc nitrate, and can maintain a polyhedral morphology after high-temperature calcination. It had the highest ORR catalytic activity compared to the other four catalyst materials, which proved that there is a certain relationship between morphology and performance. This paper will provide a useful reference and new models for the development of high-performance ORR catalysts without precious metals.

scholarly journals From Fox’s Microspheres into Primitive Life: An Inferencing Hypothesis on the Origin of Life

2018 ◽  
Author(s):  
Zhu Hua
Keyword(s):  
Catalytic Activity ◽  
Chemical Reactions ◽  
Dissipative Structure ◽  
Peptide Bond ◽  
Space Structure ◽  
Space Structures ◽  
High Catalytic Activity ◽  
Simulation Experiments ◽  
Large Molecular Weight ◽  
The Origin Of Life

The microspheres constituted by proteinoids synthesized from Fox’s simulation experiments. They had peptide bond structure and weak catalysis, as well as proliferated themselves. Such microspheres were believed the models for primitive life. Due to lack of metabolism and self-reproduction, the microspheres could not meet requirements of life. Thus, how microspheres could evolved into primitive life remain unsolved mysteries. The microspheres were supposed a dissipative structure and the processes of absorption and hydrolysis could be balanced to maintain their stability by consuming proteinoid. Proteinoid molecules differed in their life spans, which were mainly determined by their multi-space structures. Consequently, molecule selection and retention could occur spontaneously in microspheres and lead to a more organized and stabilized structure of the whole microsphere with time through dissipative process. More complex chain network of chemical reactions could happen in microspheres because the proteinoid with complex, ordered multi-space structure and relatively high catalytic activity would retain. In such microspheres, nucleotides could produce and further aggregate into RNA. The synthesis of real proteins could take place with RNA as the template catalyzed by proteinoids or RNA inside microspheres. When template-based protein molecules replaced the proteinoid inside the microspheres, a protein-based self-catalyzed network of chemical reactions could take place. It is plausible if Fox’s proteinoids microspheres is to dawn on a dissipative structure, then molecule selection could occur spontaneously by “dissipative” proteinoids, and the microspheres would acquire catalytic activity due to preserved the proteinoid with a large molecular weight and relatively complex and ordered multi-space structure, and relatively high catalytic activity. Thus the microspheres would spontaneously go to self-organizing, and evolve into primitive life.

scholarly journals A Combined Deep Eutectic Solvent–Ionic Liquid Process for the Extraction and Separation of Platinum Group Metals (Pt, Pd, Rh)

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7204
Author(s):  
Olga Lanaridi ◽  
Sonja Platzer ◽  
Winfried Nischkauer ◽  
Andreas Limbeck ◽  
Michael Schnürch ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Mixed Model ◽  
Deep Eutectic Solvent ◽  
Precious Metals ◽  
Platinum Group Metals ◽  
Environmentally Benign ◽  
Extraction Capacity ◽  
Acidic Solutions ◽  
Extraction And Separation ◽  
Platinum Group

Recovery of platinum group metals from spent materials is becoming increasingly relevant due to the high value of these metals and their progressive depletion. In recent years, there is an increased interest in developing alternative and more environmentally benign processes for the recovery of platinum group metals, in line with the increased focus on a sustainable future. To this end, ionic liquids are increasingly investigated as promising candidates that can replace state-of-the-art approaches. Specifically, phosphonium-based ionic liquids have been extensively investigated for the extraction and separation of platinum group metals. In this paper, we present the extraction capacity of several phosphonium-based ionic liquids for platinum group metals from model deep eutectic solvent-based acidic solutions. The most promising candidates, P66614Cl and P66614B2EHP, which exhibited the ability to extract Pt, Pd, and Rh quantitively from a mixed model solution, were additionally evaluated for their capacity to recover these metals from a spent car catalyst previously leached into a choline-based deep eutectic solvent. Specifically, P66614Cl afforded extraction of the three target precious metals from the leachate, while their partial separation from the interfering Al was also achieved since a significant amount (approx. 80%) remained in the leachate.

Spectrographic Analysis of Fire Assay Beads for the Platinum Group Metals and Gold

1974 ◽  
Vol 28 (1) ◽  
pp. 23-25 ◽  
Author(s):  
P. G. Sim
Keyword(s):  
Precious Metals ◽  
Platinum Group Metals ◽  
Rapid Screening ◽  
Spectrographic Analysis ◽  
Fire Assay ◽  
Platinum Group

By arcing a 10-mg fire assay bead at 7 A on a Cu cathode, bead ejection is avoided without buffering. Sensitivities for the precious metals are in the range 0.01 to 0.5 µg and precisions between 8 and 18%. The technique is suitable for rapid screening of fire assay beads for the precious metals.

scholarly journals Precious metals recovery from aqueous solutions using a new adsorbent material

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Oana Grad ◽  
Mihaela Ciopec ◽  
Adina Negrea ◽  
Narcis Duțeanu ◽  
Gabriela Vlase ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solutions ◽  
Precious Metals ◽  
Platinum Group Metals ◽  
Isotherm Models ◽  
Order Kinetic ◽  
Metallic Ions ◽  
Good Efficiency ◽  
Gas Treatment ◽  
Platinum Group

AbstractPlatinum group metals (PGMs) palladium, platinum, and ruthenium represent the key materials for automotive exhaust gas treatment. Since there are no adequate alternatives, the importance of these metals for the automotive industry is steadily rising. The high value of PGMs in spent catalysts justifies their recycling. Therefore, it is really important to recovery platinum group metals from aqueous solutions. Of the many PGMs recovery procedures, adsorption is a process with a good efficiency, but an important role is played by the adsorbent material used into the process. In order to improve the adsorption properties of materials were developed new methods for chemical modification of the solid supports, through functionalization with different extractants. In present paper a new adsorbent material (Chitosan-DB18C6) was used for PGMs recovery. The new adsorbent material was produced by impregnating Chitosan with dibenzo-18-crown-6-ether using Solvent Impregnated Resin (SIR) method. The crown ethers were chosen as extractant due to their known ability to bind metallic ions, whether they are symmetrically or unsymmetrically substituted. In order to determine the PGMs recovery efficiency for new prepared adsorbent material the equilibrium and kinetic studies were performed. Also, to study the PGMs adsorption mechanism the experimental data were modelled using pseudo-first-order and pseudo-second order kinetic models. Experimental data were fitted with three equilibrium isotherm models: Langmuir, Freundlich and Sips. The results proved that new adsorbent material (Chitosan-DB18C6) is an efficient adsorbent for PGMs recovery from aqueous solutions.

scholarly journals Recovery of Platinum Group Metals from Spent Automotive Catalysts Using Lithium Salts and Hydrochloric Acid

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6843
Author(s):  
Shunsuke Kuzuhara ◽  
Mina Ota ◽  
Ryo Kasuya
Keyword(s):  
Precious Metals ◽  
Lithium Ion ◽  
Platinum Group Metals ◽  
Leaching Rate ◽  
Electrolytic Solution ◽  
Matrix Component ◽  
Aqua Regia ◽  
Automotive Catalysts ◽  
Chlorine Gas ◽  
Platinum Group

The recovery of platinum group metals (PGMs) from waste materials involves dissolving the waste in an aqueous solution. However, since PGMs are precious metals, their dissolution requires strong oxidizing agents such as chlorine gas and aqua regia. In this study, we aimed to recover PGMs via the calcination of spent automotive catalysts (autocatalysts) with Li salts based on the concept of “spent autocatalyst + waste lithium-ion batteries” and leaching with only HCl. The results suggest that, when Li2CO3 was used, the Pt content was fully leached, while 94.9% and 97.5% of Rh and Pd, respectively, were leached using HCl addition. Even when LiF, which is a decomposition product of the electrolytic solution (LiPF6), was used as the Li salt model, the PGM leaching rate did not significantly change. In addition, we studied the immobilization of fluorine on cordierite (2MgO·2Al2O3·5SiO2), which is a matrix component of autocatalysts. Through the calcination of LiF in the presence of cordierite, we found that cordierite thermally decomposed, and fluorine was immobilized as MgF2.

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