User:Graybeard Timer/sandbox

Potassium ferrite, (sometimes potassium monoferrite) is an olive green solid that forms as the result of solid state reactions between iron oxide and potassium compounds. It is highly hygroscopic and is unstable at room temperature. Notably, it is considered to be the catalytically-active phase of industrial catalysts for the production of styrene from ethylbenzene.

Preparation
Potassium ferrite is produced by the reaction of oxides of potassium and iron in various forms.


 * FeO(OH) + KOH <-> KFeO2 + H2O

In the laboratory it is often synthesized from red iron oxide (hematite) and potassium oxide in the form of potassium carbonate at temperatures higher than 800 °C to evolve the carbon dioxide away within reasonable time:


 * Fe2O3 + K2CO3 → 2 KFeO2 + CO2

Otherwise, it is normally formed at temperatures in the order of 600 °C under working conditions after some of the precursor iron oxide has been reduced to magnetite.

Stability
Potassium ferrite is unstable in the atmosphere at ambient temperature and decomposes rapidly forming a mixture of hematite, non- stoichiometric magnetite and basic iron oxides, and into complex mixtures of potassium hydroxide-carbonate phases.