Potassium oxide is a compound of potassium and oxygen. (K2O) is a highly reactive solid, and if ingested or breathed in it will target the liver, heat, and the central nervous system. potassium oxide is produced from the reaction of potassium and oxygen. it will absorb water and create an explosive reaction. Potassium alone was discovered by Sir Humphry David in 1807, but I don’t know who discovered potassium oxide.