Palladium (B), atomic number 46, atomic weight 106.42, element name comes from the asteroid Wu Nvxing discovered in 1802. British chemist and physicist Wollaston separated new elements palladium and rhodium from crude platinum. The content of palladium in the earth's crust is about 100 million, ranking first among platinum elements.
The history and use of palladium
As early as 1700, miners in Brazil realized that metal podre is called Europodre, which is a natural alloy of palladium and gold, and is "worthless gold". But palladium was not extracted from it first, but from platinum, which was realized by William wollaston in 1803. He pointed out that when he dissolved ordinary platinum in aqua regia (nitric acid+hydrochloric acid), not all platinum was dissolved.
He finally extracted palladium from the residue. Instead of announcing his discovery, he sold the new metal as "new silver". Richard cheney Vickers bought some, studied it and announced that it was an alloy of mercury and platinum. 1805 In February, wollaston showed his discoverer and gave a comprehensive and convincing description of metals and their properties.
Most palladium is used in catalytic converters of automobiles. It is also used in jewelry and some filling materials and crowns. Platinum is an alloy of gold, which changes color by alloying with another metal (sometimes palladium). Ceramic capacitors for notebook computers and mobile phones in electronic industry. These consist of palladium layers sandwiched between ceramic layers. Refined palladium is a good catalyst, which can be used for hydrogenation and dehydrogenation. Hydrogen diffuses easily through heated palladium, which provides a method for separating and purifying gas.
Reference to the above content: Baidu Encyclopedia-Palladium