Palladium is a chemical element with atomic number 46 and chemical symbol Pd. It is a precious metal, which belongs to the platinum group elements with platinum, rhodium, ruthenium, silver and gold. Palladium is a silvery-white metal with good ductility, toughness and corrosion resistance.

Palladium has many applications, the most common of which is used as a catalyst in automotive catalytic converters to convert harmful gases into environmentally friendly substances. In addition, palladium is also used in the manufacture of jewelry, electronic equipment, chemical catalysts, medical devices, dental restoration materials, etc.

Palladium is chemically relatively stable and does not react easily with other elements, but it can react with hydrogen to form palladium hydrides. Palladium can also react with chlorine, bromine, and iodine to form corresponding halides. Palladium can be dissolved in acidic solutions such as hydrochloric acid solutions and reduced under the action of hydrogen.

Palladium is relatively rare in nature, and it usually coexists with metals such as nickel, platinum and copper. Palladium is mainly obtained by mining the ore containing it and recovering it from spent catalysts. Currently, Russia and South Africa are the world's leading producers of palladium.

In general, palladium is an important precious metal with a wide range of applications, especially in environmental protection, chemical, electronics and other fields. Due to its relatively scarce supply, the price of palladium is relatively high, making it an important investment product.