From Wedding Bands to Catalytic Converters

The platinum-group metals comprise six distinct types: palladium, platinum, iridium, osmium, rhodium and ruthenium. The catalytic properties of these metals is excellent. For example, platinum’s wear and tarnish-resistance characteristics are well-suited for making fine jewelry. Other distinctive properties are resistance to chemical attack, excellent high-temperature characteristics and stable electrical properties.

Since 1979, the automotive industry has emerged as the principal consumer of platinum-group metals. Palladium, platinum and rhodium have been used as oxidation catalysts in catalytic converters to treat automobile exhaust emissions by reducing the toxicity of emissions from an internal combustion engine. In addition to their use on automobiles, catalytic converters are also used on forklifts, mining equipment, trucks, buses, trains and other engine-equipped machines. A catalytic converter provides an environment for a chemical reaction whereby toxic combustion byproducts are transformed into less-toxic gases.

Platinum-supported catalysts are used in the refining of crude oil, reforming and other processes used in the production of high-octane gasoline and aromatic compounds for the petrochemical industry.

Other uses for platinum-group metals include:

Palladium: An extremely pliable material, palladium can be rolled into thin sheets or drawn into fine wire. It is very resistant to corrosion, but susceptible to attack from strong acids. Palladium is used to purify gas in catalytic converters, as an alloying element in white gold for jewelry, in scientific instruments and for electroplating. Palladium is also used in dentistry as filling material and sometimes in dental instruments.

Platinum: Platinum is soft and malleable, with good resistance to corrosion and chemical contact. It is used in a number of different applications, including electrical resistance wires, electrodes, catalytic converters, coatings on missile nose cones, jet engine fuel nozzles, jewelry, electrical contacts and photography. Platinum is the only metal that can be successfully soldered to glass without causing it to break.

References:
USGS Minerals Information: Platinum-Group Metals/Statistics and Information
http://minerals.usgs.gov/minerals/pubs/commodity/platinum

The DTI Manufacturing Advisory Service – fact sheet
http://www.mas.dti.gov.uk