Palladium is a rare, and lustrous silvery-white metal. It belongs to the Platinum Group of metals, along with Platinum, Rhodium, Ruthenium, Iridium and Osmium, which it shares similar chemical properties with. The metal is soft and ductile when annealed, and has the lowest melting point and density within the platinum group.
A significant supply of palladium is used in catalytic converters–emission control devices which convert as much as 90% of the toxic gases in automobile exhaust into less noxious substances (nitrogen, carbon dioxide and water vapour), by catalysing a redox reaction. Other applications of Palladium are in electronics, medicine, dentistry, hydrogen purification, groundwater treatment, and jewellery. Palladium is also a key component in fuel cells, which react hydrogen with oxygen to produce electricity, heat, and water.