Platinum group elements rhodium

Rhodium is recovered from platinum and other ores by refining and purification processes that start by dissolving the other platinum group metals and related impurities with strong acids that do not affect the rhodium itself Any remaining platinum group elements are removed by oxidation and bathing the mixture in chlorine and ammonia. 

Capobianco, C.H. Drake, M. 1990. Partitioning of ruthenium, rhodium, and palladium between spinel and silicate melt and implications for platinum-group element fractionation trends, Geochimica et Cosmochimica Acta, 54, 869-874. 

Distributions of the platinum group elements (PGEs) are shown in Fig. 12.8. The distribution of ruthenium (Ru) is unknown, but concentrations are estimated to be less than 50 fmol kg-1. The distributions of rhodium (Rh) and palladium (Pd) (Period 5) show significant surface depletions relative to deep waters and overall concentrations are somewhat less than 1 pmol kg 1. 

Jochum K. P. (1996) Rhodium and other platinum-group elements in carbonaceous chondrites. Geochim. Cosmochim. Acta 60, 3353-3357. 

Rhodium is one of the platinum group elements, and is found at very low concentrations in the Earth s crust. Rhodium was discovered by William Hyde... 

Lustig S and Sghramel P (2000) Platinum bioaccumulation in plants and overview of the situation for palladium and rhodium. In Zereini F and Alt F, eds. Anthropogenic platinum-group element emission their impact on man and environment, pp. 95-104, Springer Verlag, Berlin-Hei-delberg. 

The saltiness of the oceans was well known from ancient times and salt was used for domestic uses. But the major composition of sea water was yet to be determined. As early as 1820 William Wollaston, the discoverer of palladium and rhodium, predicted the presence of potassium in sea water and then proceeded to determine its concentration using gravimetric analytical techniques, based on the newly discovered platinum group elements and the formation of potassium-platinum compounds. 

Platinum group elements (PGE) are used as catalysts in a variety of industrial, chemical and pharmaceutical applications, such as in the production of pesticides and dye stuffs and in the processing of polymers. These rare noble metals, notably platinum (Pt), rhodium (Rh) and palladium (Pd), are also used as catalysts in automobile catalytic converters to reduce the emission of carbon monoxide (CO), nitrogen oxides (NOJ and hydrocarbons (HC) in exhaust fumes. This application, in fact, accounts for the largest consumption of the global supply of these metals on a per weight basis. In 2008, for instance, catalytic converter producers consumed a total of 52, 47 and 86% of the world s Pt, Pd and Rh, respectively (Matthey 2008). Pd use by the catalyst industry increased by a factor of six from 1993 to 2008 (Matthey 1996, 2008). 

Ruehle T, Schneider H, Find J, Herein D, Pfaender N, Wild U, Schloegl R, Nachtigall D, Artelt S, Heinrich U (1997) Preparation and characterisation of Pt/A1203 aerosol precursors as model Pt-emissions from catalytic converters. Appl Catal B Environ 14 69-84 Schafer J, Hannker D, EckWdt JD, Stiiben D (1998) Uptake of traffic-related heavy metals and platinum group elements PGE by plants. Sci Total Environ 215 59-67 Speranza A, Leopold K, Maier M, Taddei AR, Scoccianti V (2009) Pd-nanoparticles cause Increased toxicity to kiwifruit pollen compared to soluble Pd. Environ Pollut (submitted) Sures B, Zimmermann S (2007) Impact of humic substances on the aqueous solubility, uptake and bioaccumulation of platinum, palladium and rhodium in exposure studies with Dreissena polymorpha. Environ Pollut 146(2) 444 51... 

Zhu H, Han J, Xiao JQ, Jin Y (2008) Uptake, translocation, and accumulation of manufactured iron oxide nanoparticles by pumpkin plants. J Environ Monit 10 713-717 Zimmerman S, Alt F, Messerschmidt J, Von Bohlen A, Taraschewski H, Sures B (2002) Biological availability of traffic-related platinum-group elements (palladium, platinum, and rhodium) and other metals to the zebra mussel (Dreissena polymorpha) in water containing road dust. Environ Toxicol Chem 21(12) 2713-2718... 

Gomez B, Gomez M, Sanchez JL, Fernandez R, Palacios MA (2001) Platinum and rhodium distribution in airborne particulate matter and road dust. Sci Total Environ 269 131-144 Gomez B, Palacios MA, Gomez M, Sanchez JL, Morrison G, Rauch S, McLeod C, Ma R, Carol S, Alimonti A, Petrucci F, Bocca B, Schramel P, Zischka M, Petterson C, Wass U (2002) Levels and risk assessment for humans and ecosystems of platinum-group elements in the airborne particles and road dust of some European cities. Sci Total Environ 299 1-19 Hatch GE, Slade R, Boykin E, Hu PC, Miller FJ, Gardner DE (1985) Correlation of effects of inhaled versus intratracheally-injected metals on susceptibility to respiratory tract infection in mice. Am J Respir Dis 124 167-173... 

The platinum-group metals (PGMs), which consist of six elements in Groups 8— 10 (VIII) of the Periodic Table, are often found collectively in nature. They are mthenium, Ru rhodium, Rh and palladium, Pd, atomic numbers 44 to 46, and osmium. Os indium, Ir and platinum, Pt, atomic numbers 76 to 78. Corresponding members of each triad have similar properties, eg, palladium and platinum are both ductile metals and form active catalysts. Rhodium and iridium are both characterized by resistance to oxidation and chemical attack (see Platinum-GROUP metals, compounds). 

Ruthenium also belongs to the platinum group, which includes six elements with similar chemical characteristics. They are located in the middle of the second and third series of the transition elements (groups 8, 9, and 10). The platinum group consists of ruthenium, rhodium, palladium, osmium, iridium, and platinum. 

As its title implies, this review restricts itself to describing and discussing compounds of platinum group metals—i.e., of ruthenium, rhodium, palladium, osmium, iridium, and platinum—although the compounds of the other transition elements and even some post-transition elements are either fully analogous or closely related to those of the platinum metals. 

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