Potassium Superoxide

As a laboratory reagent, potassium superoxide has only a few applications. KO2 is frequently researched in organic solvents due to its reaction with water. The Russian Space Agency has used potassium superoxide successfully for Soyuz spacecraft and spacesuits. However, KO2has only been utilised in limited quantities in scuba rebreathers because of its strong interaction with water. It has also been used in rebreather canisters for firefighting and mining rescue work.

Potassium superoxide

The inorganic compound potassium superoxide has the formula KO2. It is a paramagnetic solid that is yellow and decomposes when exposed to moist air. It is a rare instance of a stable superoxide anion salt. It is utilised in rebreathers, spaceships, submarines, and spacesuit safety systems as an H2O dehumidifier, CO2 scrubber, and O2 generator.

Potassium superoxide is a reactive oxidant that acts readily with water, acids, and flammable materials (organic compounds and powdered graphite). When mixed with organic oils such as kerosene, even dry superoxide can form an impact-sensitive explosive molecule. This compound is utilised in submarines and spacecraft to absorb CO2 and produce potassium carbonate and oxygen.

Chemical formula of potassium superoxide

Superoxide is a chemical compound that has a superoxide ion in it. Such ions have the chemical symbol O2−. Oxygen molecules are reduced by one electron to produce it.

One electron reduction in O2 produces a superoxide ion. This is because each atom of molecular oxygen has two unpaired electrons. Because O2 ‘s net charge changes to -1 when an electron is added to one of its degenerate molecular orbitals, superoxide is formed.

One unpaired electron is found in the valence shell of Potassium’s electronic configuration, which is  [Ar]4s1. Consequently, it quickly loses this electron to produce K+ ion, which then interacts with O2 − ion to generate potassium superoxide related by ionic bonding. Its chemical formula is KO2. In this case, the chemical reaction goes like this:

Procurement of potassium superoxide

1. Industrial process: potassium superoxide (KO2) is prepared using sodium metal in place of potassium chloride to procure more than 97 percent purity of potassium metal. The molten Potassium is then activated and sent to a special spray gun where it is mixed with purified air before being injected into an oxidising furnace, which would be generated by combustion at 230~250 °c. 

2. Oxidation method: compressed air oxidises potassium metal to produce potassium superoxide by removing oil, water, and carbon dioxide.

Reactivity profile

Potassium superoxide is a potent oxidant. This compound occurs on the surfaces of potassium metal, whether solid or molten when exposed to air. For an example of potassium superoxide, explosions happened when attempts were made to extinguish a burning potassium canister with powdered graphite.

When a large amount of highly oxidised potassium metals were dropped into ethyl alcohol, an immediate blast occurred, shattering the dish completely. The presence of potassium superoxide was believed to be the source of the reaction.

Potassium superoxide should never be applied to pure organic compounds (hydrocarbons) due to the potential of ignition and a violent explosion. Copper, Potassium, tin and zinc oxidise with incandescence. Diselenium dichloride and superoxide react violently.

Uses of potassium superoxide

• As a CO2 scrubber, dehumidifier, and oxygen generator, potassium oxide is a vital component in the modern world.
• It is used in rebreathers for firefighting and mine rescue operations.
• It is also utilised in the life support systems of spaceships, submarines, and spacesuits.
• One application for potassium superoxide, KO2, is the production of oxygen. It is capable of absorbing carbon dioxide while also releasing oxygen. In the breathing apparatus, this feature has been utilised. 

Risks involved

• Explosive reaction when carbon, 2-aminophenol, and tetrahydrofuran are heated at 65°C.
• When combined with hydrocarbons, it forms a friction-sensitive explosive combination.
• Selenium dichloride reacts violently with ethanol and potassium-sodium alloy.
• When in contact with organic substances, it has the potential to ignite.
• The oxidation of metals in the presence of an incandescent substance. When heated to the decomposition point, it generates toxic fumes containing KO2.

Health hazard

• Harmful if toxic fumes are inhaled
• Ingestion or contact with fumes, dusts, or substances may result in severe harm, burns (skin, eyes), or death.
• Fires can release irritants and toxic gases.
• Toxic gases or dust can accumulate in confined spaces (basement, tanks, hopper/tank vehicles, etc.).
• Pollution may occur due to runoff from fire prevention or diluting water.

Potential fire hazard

• May spontaneously combust due to friction, heat, or contamination.
• Using these materials in a fire will speed up the process of burning. Possibility of igniting combustible materials.
• Some chemicals will react violently with hydrocarbons (fuels).
• When heated, containers have a risk of explosion.
• Runoff can cause a risk of fire or explosion.

Safety profile

• Potassium superoxide is a first-class oxidant that can induce burning and even explosion when it comes into contact with flammable, organic, or reducing agents.
• A low-temperature ventilation system and drying system are used in the warehouse.
• Fuel and organic materials are kept separate from them in the storage facility.
• The container’s mouth shall be covered in an iron drum with an explosion-proof device.
• Must be stored in a well-ventilated, dry warehouse.
• The packing must be entirely sealed and completely resistant to moisture.
• Vehicles should be covered from rain and direct sunlight.
• It should be handled gently during loading and unloading to avoid impact and packaging damage.

Conclusion

Potassium superoxide is produced commercially by the atomisation of molten Potassium with air. The resulting oxidation product is a finely split yellow powder that approaches KO2in chemical composition. An example of Potassium superoxide is a powder of the calcium carbide type. At elevated temperatures, the crystal structure of KO2 is cubic, identical to that of NaCl, except that the position of CI is substituted by O2 . When melted thoroughly at 450-500 degrees Celsius, it turns into a golden yellow powder. It has a high hygroscopicity, and the water-intense reaction breakdown of oxygen and alkaline peroxide mixture is quite fast. When potassium superoxide reacts with moist carbon dioxide gas, potassium carbonate and oxygen are produced. It has a more remarkable ability than peroxides to absorb oxygen atoms.KO2