Palladium(II) oxide

  • Palladium
  • Palladiummonooxid

Greenish black, odorless powder

Fixed

8.3 g · cm -3

750 ° C ( decomposition)

Insoluble in water and acids

Risk

  • 349.95 kJ / mol ( gas)
  • -0.09 KJ / mol (crystal)

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Palladium ( II) oxide is the most stable oxide of palladium. It is a greenish- black, crystalline solid that melts at 750 ° C.

Production and representation

Palladium oxide is formed by heating palladium sponge in the presence of oxygen at 350 ° C. The oxide is obtained as a black powder. Especially for catalytic applications, it may be obtained at 600 ° C followed by leaching the water-soluble residue by heating a mixture of palladium (II ) chloride and potassium or sodium nitrate. The hydrate can be obtained by precipitation of palladium ( II) nitrate are obtained with sodium hydroxide. The brown oxide hydrate can be converted by heating in the dehydrated form. The solubility in acids decreases with decreasing water content.

Properties

Physical Properties

Palladium ( II) oxide is in the form of greenish black tetragonal crystals. It is insoluble in water and acids, but slightly soluble in aqua regia.

Chemical Properties

Palladium ( II) oxide decomposes above 750 ° C to palladium metal. With the addition of lye yellow-brown palladium (II ) oxide hydrate PdO falls out · x H2O, which can not be drained without concomitant release of oxygen. It is soluble in contrast to anhydrous PdO into acids.

Use

Palladium oxide is used for the production of palladium hydrogenation catalyst by reduction with hydrogen.

CAS registry number PubChem Palladium(II) chloride Palladium(II) nitrate Tetragonal crystal system
630954
de