Short answers, pulled from the story.
Palladium was discovered by the English chemist William Hyde Wollaston, who recorded the new noble metal in his lab book in July 1802. He named it in August 1802 after the asteroid 2 Pallas, which had itself been discovered just two months earlier. Wollaston publicly disclosed that he was the discoverer in a publication in 1805.
Palladium is used in catalytic converters to convert as much as 90 percent of the harmful gases in automobile exhaust, including hydrocarbons, carbon monoxide, and nitrogen dioxide, into nontoxic substances such as nitrogen, carbon dioxide, and water vapor. More than half of the world's palladium supply is consumed by this single application.
Russia is the top producer of palladium, with Norilsk Nickel accounting for 39 percent of global production. The most important commercial sources are the Norilsk-Talnakh deposits in Siberia, the Sudbury Basin in Ontario, Canada, and the Bushveld Igneous Complex in South Africa. As of 2022, overall mine production of palladium reached 210,000 kilograms globally.
Palladium prices hit an all-time high of 2,981.40 dollars per troy ounce on the 3rd of May 2021, driven mainly by speculation about catalytic converter demand from the automobile industry. An earlier price spike to 1,340 dollars per troy ounce in January 2001 was caused by delays to Russian palladium exports, which led the Ford Motor Company to stockpile the metal and subsequently lose nearly one billion US dollars when prices fell.
Palladium has a uniquely high capacity to absorb hydrogen at room temperature, forming palladium hydride. This property made it a key component in the controversial cold fusion experiments of the late 1980s. Palladium's ability to absorb hydrogen without losing its ductility has also attracted interest as a potential hydrogen fuel storage medium, though its cost has so far made that use impractical.
Palladium has been used in jewellery since 1939 as an alternative to platinum in white gold alloys. In January 2010, assay offices in the United Kingdom introduced hallmarks for palladium, making hallmarking mandatory for all jewellery advertising pure or alloyed palladium. Articles can be marked as 500, 950, or 999 parts of palladium per thousand of the alloy.