Palladium was discovered by Wollaston in 1803. It is found with other platinum group metals in Placer deposits in Russia, north and south America, Australia and Ethiopia. It has also been found in Ontario and South Africa in copper-nickel deposits.
Its ability to be separated from other platinum group metals is strongly influenced by which metals they are.
- Palladium is steel white in appearance
- It does not tarnish in air
- It has the lowest density of all platinum group metals
- It has the lowest melting point of all platinum group metals
- In the annealed state it is soft and ductile
- Cold working significantly increases harness and strength
- Palladium is attacked by sulfuric and nitric acids
- It can absorb up to 900 times it own volume in hydrogen.
- Palladium can be used for purification of hydrogen as it readily diffuses through the heated metal.
- Fine palladium powders are used as catalysts for hydrogenation and dehydrogenation reactions
- Its alloys are used in jewellery e.g. white gold, which is gold that has been decolourised by the addition of palladium
- Surgical instruments
- Electrical contacts
- Multilayer ceramic capacitors (MLCC)
- Oxygen sensors
- Brazing alloys
- Catalysts for auto applications