Palladium

A fine palladium powder is used as a catalyst for hydrogenation and dehydrogenation chemical reactions.   Palladium is alloyed with precious metals and used in jewelry where it adds strength and hardness.   "White gold" is an alloy with gold decolorized by palladium.   Like gold, palladium can be beaten into very fine sheets and drawn into fine wire to be used in dentistry, watchmaking, surgical instruments and electrical contacts. ^{Lide 4-21}

Palladium was discovered in 1803 by William Wollaston, a British chemist.   Hydrogen passes easily through heated palladium, so it can be purified in this way.   Palladium is found with the platinum group of elements in placer deposits and in nickel-copper deposits.   The process by which it is separated from other metals depends on the type of deposit. ^{Lide 4-21}