It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Some features of ATS will be disabled while you continue to use an ad-blocker.
The catalyst itself is most often a precious metal. Platinum is the most active catalyst and is widely used, but is not suitable for all applications because of unwanted additional reactions (see below) and high cost.
Palladium and rhodium are two other precious metals used. Rhodium is used as a reduction catalyst, palladium is used as an oxidation catalyst, and platinum is used both for reduction and oxidation. Cerium, iron, manganese and nickel are also used, although each has its own limitations. Nickel is not legal for use in the European Union (because of its reaction with carbon monoxide into nickel tetracarbonyl). Copper can be used everywhere except North America,[clarification needed] where its use is illegal because of the formation of dioxin.
Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs).
These have similar chemical properties, but palladium has the lowest melting point and is the least dense of them.
Over half of the supply of palladium and its congener platinum goes into catalytic converters, which convert up to 90% of harmful gases from auto exhaust (hydrocarbons, carbon monoxide, and nitrogen dioxide) into less-harmful substances (nitrogen, carbon dioxide and water vapor).
In the run up to 2000, the Russian supply of palladium to the global market was repeatedly delayed and disrupted because the export quota was not granted on time, for political reasons. The ensuing market panic drove the price to an all-time high of $1100 per troy ounce in January 2001. Around this time, the Ford Motor Company, fearing auto vehicle production disruption due to a possible palladium shortage, stockpiled large amounts of the metal purchased near the price high. When prices fell in early 2001, Ford lost nearly US$1 billion.
Eggs of fish or snails were transferred to 50 ml plastic Petri dishes containing different solutions of PtCl2 (platinum standard solution of 1000 μg/ml in 2% HCl, Ultra Scientific, Wesel, Germany) with the following nominal concentrations: 0.1, 1, 10, 50, 100 and 200 μg/l PtCl2 and the control medium, respectively.
3.2. Genotoxicity of PtCl2 in D. rerio
Comet assay data revealed no genotoxic hazard of the tested PtCl2 concentrations in cells derived from D. rerio (Fig. 2).
3.3. Genotoxicity of PtCl2 in M. cornuarietis
In contrast to the results obtained for D. rerio, PtCl2 revealed a considerable genotoxic hazard potential for M. cornuarietis. Except for the lowest tested concentration of 0.1 μg/l PtCl2, tail moments of Pt-exposed snail cells were significantly higher than controls (Fig. 3). With rising concentration of PtCl2 up to 100 μg/l, an increasing tail moment was observed in cells of M. cornuarietis. Medians of the tail moments of cells of M. cornuarietis exposed to 50 and 100 μg/l PtCl2 were in the same order of magnitude or even slightly higher than the tail moments of the positive controls. Only the tail moments recorded for snails exposed to the highest tested concentration of 200 μg/l PtCl2 were, though elevated above negative control levels, significantly lower than after exposure to 100 μg/l PtCl2 (Fig. 3).
and noticed that the internals of the converter had basically disapeared from years of use. there were still a few loose chunks of it in there, but most of it was gone.
Regardless, a properly tuned engine will keep that converter in good health forever, or until somebody steals it for the platinum.