What is Palladium?

Palladium is a soft silver-white metal with symbol Pd and atomic number 46. A rare silver-white transition metal of the platinum group to which it resembles, it is extracted from copper and nickel ores and is primarily used as an industrial catalyst and in jewelry.

Palladium has the least dense and the lowest melting point of the platinum group metals. It is soft and ductile when annealed and greatly increases its strength and hardness when it is cold-worked. Palladium is chemically attacked by sulphuric, nitric acid and hydrochloric acid in which it dissolves slowly. This metal also does not react with oxygen at normal temperatures (and thus does not tarnish in air). Palladium heated to 800°C produce layer of palladium(II)-oxide (PdO). It lightly tarnishes in moist atmosphere containing sulphur.

This metal has the strange ability to absorb up to 900 times its own volume of hydrogen at room temperatures. It is thought that this possibly forms palladium hydride (PdH2) but it is not yet clear if this is a true chemical compound.

When palladium has absorbed large amounts of hydrogen, it can swell up, like a sponge full of water, visible to the naked eye.

When it is finely divided, palladium forms a good catalyst and is used to speed up hydrogenation and dehydrogenation reactions, as well as in petroleum cracking. A large number of carbon-carbon bond forming reactions in organic chemistry (such as the Suzuki coupling) are facilitated by catalysis with palladium compounds. It is also alloyed and used in jewelry.

The main use of palladium today is in catalytic converters. Much research is in progress to discover ways to replace the much more expensive platinum with palladium in this application. Palladium is increasing used also in other industrial activities.

Palladium is one of the two metals which can be alloyed with gold to produce White gold. (Nickel can also be used.)

Similar to gold, palladium can be beaten into a thin leaf form as thin as 100 nm (1/250,000 in). Since 1939 palladium itself has been increasingly used as a precious metal in jewelry as well as palladium coins.

Palladium is found as a free metal and alloyed with platinum and gold with platinum group metals in placer deposits of the Ural Mountains, Australia, Ethiopia, South and North America. It is commercially produced from nickel-copper deposits found in South Africa, Ontario and Siberia; the huge volume of ore processed makes this extraction profitable in spite of the low proportion of palladium in these ores. The world's largest single producer of Palladium is MMC Norilsk Nickel, headquartered in Moscow.

In 2000, Ford Motor Company created a price bubble in palladium by stockpiling large amounts of the metal, fearing interrupted supplies from Russia. As prices fell in early 2001, Ford lost nearly $1 billion U.S. dollars.