Oxygen Production

Small amounts of oxygen can be generated in the laboratory by heating potassium chlorate (KCl0₃) with a manganese dioxide (Mn0₂) catalyst. Potassium chlorate is "anxious" to give up its oxygen atoms to form potassium chloride (KCl) and oxygen.

Heating alone does not release the oxygen very effectively nor does mixing the potassium chlorate with manganese dioxide. If you heat a mixture of the two chemicals, however, you get plenty of free oxygen. The manganese dioxide in this case is not consumed by the reaction. It is a true catalyst, and this particular reaction is a classic in elementary chemistry classes because it clearly demonstrates a catalytic reaction.

Electrolysis of water

Small amounts of oxygen can also be obtained by electrolyzing water. Strictly speaking, electrolyze a mixture of water (not just water) and a good electrolyte such as sodium sulfate (Na₂S0₄), or Glauber's salt. The sodium sulfate does not participate directly in the reaction, so the scheme will not produce sodium, sodium hydroxide, nor any sulfates. Rather, the sodium sulfate (or similar salt) improves performance by neutralizing the ionic charges throughout the bath.

Oxygen is produced on a commercial scale by the fractional distillation of liquid air. The critical temperature of oxygen is - 118°C. Since liquid air is held at about 198°C, fractional distillation produces nitrogen (N₂) first at -147°C, followed by argon (Ar), and oxygen.

Commercial production of Oxygen in Steel Industry

Most commercially produced oxygen is consumed by the steel industry. Pure oxygen is blown over the molten steel where it converts excess carbon to carbon dioxide gas and oxidizes other impurities so they can later be removed with the slag.