Description:

Palladium was discovered in 1803 by W.H. Wollaston during refining and purification of- platinum metal. This new metal was found in the aqua regia extract of native platinum and was detected in solution after platinum was precipitated. It was removed as ammonium chloroplatinate. Treating this solution with mercurous cyanide precipitated a yellow palladium complex salt. The precipitate was washed and ignited to form palladium metal. Wollaston named the element palladium after the newly discovered asteroid Pallas.
Palladium in nature is always associated with other platinum group metals. Its abundance in earth's crust is estimated at 0.015 mg/kg, about three times more abundant than platinum. Palladium is used mostly in alloys and the majority of its alloys are used for electronics and telecommunications. They are contacts in electrical relays and automatic switching gear. Palladium-gold alloys are applied widely in dentistry and medicine. They are in devices for replacement of damaged bones and joints and as support in porcelain-overlay bridgework. Palladium alloys are used in decoration and jewelry as a substitute for gold. They are used in gems, watch cases and brooches.
One of the most important applications of palladium is to catalyze hydrogenation, dehydrogenation, and petroleum cracking. Such reactions are widely employed in organic syntheses and petroleum refining. Palladium and platinum are installed in catalytic converters in automobiles to cut down the emission of unsaturated hydrocarbon gasses.

Physical properties

Palladium is the middle element in group 10 of the transition elements (periods 4, 5, and6). Many of its properties are similar to nickel located above it and platinum just below it inthis group.
Palladium is a soft, silvery-white metal whose chemical and physical properties closelyresemble platinum. It is mostly found with deposits of other metals. It is malleable and ductile,which means it can be worked into thin sheets and drawn through a die to form very thinwires. It does not corrode. Its melting point is 1,554°C, its boiling point is 3,140°C, and itsdensity is 12.02 g/cm³

Uses:

Palladium’s ability to absorb large amounts of hydrogen makes it an excellent catalyst forchemical reactions as well as catalytic converters for internal combustion engines. Palladiumis also an excellent catalyst for cracking petroleum fractions and for hydrogenation of liquidvegetable oils into solid forms, such as corn oil into margarine. It is also used to purifyhydrogen gas by passing raw H₂ gas under pressure through thin sheets of palladium, wherethe pure hydrogen passes through the metal’s crystal structure, leaving behind impurities.Palladium is used to manufacture CO-monitoring devices because of its ability to absorbcarbon monoxide.
Palladium is used in the manufacture of surgical instruments, electrical contacts, springs forwatches and clocks, high-quality spark plugs, and special wires and as “white gold” in jewelry.Because it is noncorrosive, it is used as a coating for other metals and to make dental fillingsand crowns.

Product Image: