# Could H$_2$S$_2$O$_8$ (peroxydisulfuric acid), made in the clouds of Venus, be used for making a propellant?

The salts of the peroxydisulfate ion, S$$_2$$O$$_8^2^-$$, are strong oxidants like the perchlorates that are used in propellants for rockets.

In this answer on Chemistry stackexchange is a link to a thesis which describes the production of peroxydisulfuric acid by electrolysing concentrated sulfuric acid.

Because the clouds of Venus contain much concentrated sulfuric acid, could future missions to the atmosphere of Venus, using electrolysis of this acid to produce peroxydisulfuric acid, use this strong oxidizer to make a propellant to get back home to Earth ?

The problem in making propellant on Venus, is surely in finding the fuel, rather than the oxidizer. Oxygen can be made by electrolyzing $$\text{CO}_2$$ if necessary and while $$\text{S}_2\text{O}_8^{2-}$$ is a very strong oxidizer, meaning that it will oxidize lots of things, the mass of the sulphur atoms means that pure oxygen is probably a better rocket fuel
Where electrolysis of sulphuric acid might be useful is as a way to make hydrogen, which is in short supply on Venus. This could be used as fuel, or combined with $$\text{CO}_2$$ to make methane and water. The water can then be electrolyzed to make more oxygen and get back some of the hydrogen.
• Thank you for this answer. It would be fine if you could add some links, for instance for the making of methane and water out of hydrogen and CO$_2$. – Cornelisinspace Aug 20 at 16:39