Sciencemadness Discussion Board

Upgrade NaClO3 > NaClO4 failed : anode worn out ?

metalresearcher - 9-2-2026 at 11:17

A few days ago I did a new attempt to make perchlorate, after a successful electrolysis a year ago. I started with table salt NaCl, dissolved 250 g in 0.8 liter water with a knife tip of K2S2O8. Then let the cell run for about 32 hours at 20 Amp, using an MMO anode with a temp up till 80 C. Then I changed anodes, replaced the MMO anode by a PbO2 anode and let it run for 8-10 hours at 18 A and 70 C. The liquid I filtered out was slight yellow, but clear.
But this time the methylene blue test did not result in purple precipitation, so it failed.
What did I wrong ?