Platinaoxid

Platinaoxid, also known as platinum oxide, is a chemical compound with the formula PtO2. It is a black or dark brown solid that is insoluble in water. Platinaoxid can be prepared by the thermal decomposition of platinum salts, such as platinum nitrate or platinum dioxide hydrate. It is also formed as a product of the oxidation of platinum metal at high temperatures.

There are two main crystalline forms of platinaoxid: a hexagonal form (alpha-PtO2) and a tetragonal form (beta-PtO2). The hexagonal form is more stable at room temperature, while the tetragonal form is stable at higher temperatures. Platinaoxid is a semiconductor and exhibits catalytic properties.

Platinaoxid is used as a catalyst in various chemical reactions, including hydrogenation and oxidation. It is also employed in the preparation of other platinum compounds and in electrochemical applications. Due to its high melting point and chemical inertness, platinaoxid is considered a refractory material. Its specific density is approximately 10.2 g/cm³. When heated strongly in the absence of air, it decomposes to platinum metal. In the presence of a reducing agent or at elevated temperatures with hydrogen, it can be reduced to platinum metal.