Production of Hydroxylamine by Electrolytic Method

Production of Hydroxylamine, done by electrolysis of 50% sulphuric acid and adding 50% nitric acid. The chemical formula of hydroxylamine is NH2OH. It is easily converted into hydroxylammonium salt when subject to react with hydrochloric acid or sulphuric acid.  Ammonia with a formula NHis base and so when a hydrogen atom is removed and replaced with –OH group it becomes monoacid base it almost exists in unstable condition.

Production of Hydroxylamine

50% sulphuric acid is fed to diaphragm cell having anode as cylindrical lead and cathode as an amalgamated lead beaker with separation made by asbestos cement pot. Electrolysis is done with a supply of cooling media to remove the heat from diaphragm cell.  The diaphragm is designed in a way that anode stays inside and the cathode is placed outside with tapping to drain out the formed hydroxylamine sulphate. The two compartment formed by the asbestos cement pot is filled with 50% H2SO4.

The process works when current is passed to diaphragm. At cathode nascent hydrogen is liberated due to simultaneous addition of nitric acid is fed to the cathode compartment. The nascent hydrogen thus produced is reacted with incoming HNO3 to form Hydroxylamine  by the reaction step:

HNO3 + 6H → NH2OH +  2H2O

Hydroxylammonium sulphate is formed when Hydroxylamine is reacted with sulphuric acid present in the diaphragm cell.

2NH2OH + H2SO4 → [NH3 (OH)]2SO4  [Hydroxylammonium sulphate]

Hydroxylammonium sulphate is collected from the outlet of cathode section. As purification step, the solution is treated with barium chloride to form BaSO4 a precipitate of barium sulphate. This will give out the chloride salt of hydroxylamine by:

[NH3 (OH)]2SO4 + BaSCl2   → 2NH3 (OH)Cl + BaSO4


Hydroxylamine MSDS common properties:

Physical properties:

  • Colourless
  • Odourless
  • Crystal form
  • Melting point 33oC
  • Sp gravity 1.35
  • Soluble in alcohol and water

Chemical properties:

  • A proton acceptor
  • Decomposes to in aqueous media into N2, NO and NH3
  • Reducing agent