paladiumi

Paladiumi, known in English as palladium, is a chemical element with symbol Pd and atomic number 46. It is a silvery-white, soft, ductile metal in the platinum group, highly resistant to corrosion and oxidation at room temperature. It is a noble metal and a commodity of significant industrial importance.

Palladium is relatively rare in the Earth's crust, occurring in platinum-group metal ore deposits. Major sources include the Bushveld Complex in South Africa, the Norilsk area in Russia, and deposits in Canada and the United States. It is typically recovered as a byproduct of mining other PGMs such as platinum and nickel. Global production is concentrated in a few countries.

Palladium has high catalytic activity, especially in hydrogenation and dehydrogenation reactions, and is a key component of catalytic converters in automobiles, reducing harmful emissions. It is also used in jewelry as an alloying agent or plating, in electronics for contacts and plating, and in dentistry for some dental alloys, as well as in research on hydrogen storage. Palladium readily forms palladium hydride under hydrogen, an attribute relevant to catalysis and storage.

Palladium was discovered in 1803 by William Hyde Wollaston, who named it after the asteroid Pallas, discovered two years earlier.

In terms of safety and environment, palladium presents little acute toxicity, but inhalation of fine metal dust or fumes can be harmful; occupational exposure limits apply. Mining and processing of palladium-bearing ores raises environmental concerns typical of platinum-group metals, including energy use and waste management.