Ruthenium

Ruthenium is a chemical element with the symbol Ru and atomic number 44. It belongs to the platinum group metals, a family of six similar elements that includes platinum, palladium, rhodium, osmium, and iridium.

Ruthenium is a hard metal with a silvery-white color and is highly resistant to corrosion. It does not dissolve in common acids, even in aqua regia. It is rare in the Earth's crust; it is found mainly in nickel and platinum ores.

History and naming

The name derives from the Latin word Ruthenia, referring to the historical region of Russia and Ukraine. The element was identified and named by a chemist from the Russian Empire in the 19th century, who studied residues from platinum ore extracted from the Urals.

Chemical properties

Ruthenium exhibits a wide range of oxidation states, from −2 to +8, making it chemically versatile. Common compounds include ruthenium(IV) oxide (RuO2) and ruthenium tetroxide (RuO4), the latter being volatile and toxic. Ruthenium complexes are widely used in coordination chemistry research.

Uses

The largest application of ruthenium is in alloys to harden platinum and palladium, and in electronics such as resistors and data storage devices. It is also used as a catalyst—a substance that speeds up chemical reactions—particularly in the production of ammonia and various industrial processes. Ruthenium catalysts in organic chemistry, such as those used in olefin metathesis reactions, play a major role in the synthesis of pharmaceuticals and polymers.

Production

Ruthenium is not mined separately. It is obtained mainly as a byproduct of nickel and platinum ore refining, with South Africa and Russia being among the largest sources. Annual production is small compared to common metals, which affects both its price and availability.