Палладий(II) оксид

Химические свойства

grey to black powder

Физические свойства

Greenish black tetragonal crystals; density 8.3 g/cm³; decomposes to Pd metal at 750°C; insoluble in water and acids; slightly soluble in aqua regia.

Использование

Palladium(II) oxide is used to prepare palladium catalyst for hydrogenation. The oxide is readily reduced by hydrogen to metal.

Подготовка

Palladium(II) oxide is prepared by heating palladium sponge in oxygen at 350°C. The oxide is obtained as a black powder. The oxide also may be prepared specially for catalytic use by heating a mixture of palladium chloride and potassium nitrate at 600°C and then leaching out water-soluble residue. A hydrated form of the oxide, which is acid soluble can be prepared by precipitation from solution, for example, by hydrolysis of palladium nitrate. The brown hydrated oxide converts to black anhydrous oxide on heating. Its solubility in acids decreases with lowering of water content.