Sciencemadness Discussion Board

palladium electrodes, sodium bromate

nodrog19 - 23-6-2008 at 11:15

Will palladium electrodes corrode or are they like platinum? I know that they store alot of hydrogen (500 times their volume).

Will NaBr+3O----->NaBrO3 work better in an acidic or basic environment?

[Edited on 23-6-2008 by nodrog19]

[Edited on 23-6-2008 by nodrog19]

Klute - 23-6-2008 at 11:34

I think the bromate electrolysis must be performed in basic conditions, otherwise you just form Br2.

garage chemist - 23-6-2008 at 13:00

Palladium is unsuitable, it reacts with bromine.
Pd is the least noble of the platinum group metals and already dissolves in HNO3. It's a lot like silver.

Fortunately, a graphite anode works well for bromate production with very little erosion compared to chlorate production, as woelen has shown.

Do not add any acid or base to a bromate cell.
It produces its own base at the cathode, and bromine being liquid, not gaseous, will not escape as chlorine does, so there is no need to adjust the pH.
If you add acid, you will get bromine only, and if you add base, you get oxygen at the anode.

nodrog19 - 23-6-2008 at 13:58

thanks

plante1999 - 4-9-2011 at 07:47

Does anyone have try palladium anode in a chloride to chlorate cell ? Palladium is suposed to react with chlorine at 500 degree C and platinum at 400 degree C.

Because I have a scource of piece witch contain 1% easily extractable palladium witch I could plate on a substate.


Thanks!!!

[Edited on 4-9-2011 by plante1999]

[Edited on 4-9-2011 by plante1999]

woelen - 5-9-2011 at 01:58

No, palladium does NOT work, not at all. Your figure of 500 C is for dry chlorine gas over bulk palladium. Chlorine in aqueous solution is MUCH more corrosive and the oxidative strain at the anode will be even more strong. You will simply see your palladium electrode dissolve and no (or hardly any) Cl2 is formed at all.