Ruthenium(IV) oxide
Ruthenium oxide is the inorganic compound with the formula RuO2. This black solid is the most common oxide of ruthenium. It is widely used as an electrocatalyst for producing chlorine, chlorine oxides, and O2. Like many dioxides, RuO2 adopts the rutile structure.
Preparation
It is usually prepared by oxidation of ruthenium trichloride. Nearly stoichiometric single crystals of RuO2 can be obtained by chemical vapor transport, using O2 as the transport agent:Films of RuO2 can be prepared by chemical vapor deposition from volatile ruthenium compounds. RuO2 can also be prepared through electroplating from a solution of ruthenium trichloride.
Electrostatically stabilized hydrosols of pristine ruthenium dioxide hydrate have been prepared by exploiting the autocatalytic reduction of ruthenium tetroxide in aqueous solution. The resulting particle populations may be controlled to comprise substantially monodisperse, uniform spheres with diameters in the range 40 nm - 160 nm.
Uses
Ruthenium oxide is being used as the main component in the catalyst of the Sumitomo-Deacon process which produces chlorine by the oxidation of hydrogen chloride.RuO2 can be used as catalyst in many other situations. Noteworthy reactions are the Fischer–Tropsch process, Haber–Bosch process, and various manifestations of fuel cells.