[professor_jonny]

Hi I have created a hypochlorous acid machine from the electrolysis of salt water with a porous ceramic membrane inbetween the electrodes.

But I'm having problems with the anode being eaten the anode is made of titanium I have looked at coating this in robodum oxide as they do with comercial systems but it is extremly toxic and very expensive to handle and not an option in my country.

So I purchased a Tantalum rod for the anode which is more chemical resistant that titanium to chemicals.

When using the Tantalum rod as the annode i get no current flow but if i use it as the cathode the process works.

It is like i have creaded a diode with titanium salt water and Tantalum that oposes current flow in one direction.

With the titanium as the anode I can pull 170 amps at 48vdc but with the Tantalum as the anode i cant get any more than a few mili amps.

I have tried hydrocloric acid as a catalist but no go does any one have any idea ?

Winding the voltage up does help but it still really wont run away like with the Tantalum as the cathode.

i was guessing an oxide coating on the Tantalum but then it conducts the other way with out issue.

[utelectrode]

You may try ruthenium iridium coated titanium plate or mesh as anode, HCL as electrolyte.

[Hunter2]

Why not use carbon rods.

[Enthalpy]

Tantalum is known to grow an oxide layer until the thickness suffices to isolate, including at 200V. It's the easiest material for that purpose. It serves to make "electrochemical" capacitors.

Other such metals are aluminium (seriously pure) and more recently niobium. Aluminium tends to serve for higher voltages, up to 1000V roughly, while tantalum serves for low or very low voltages, especially as a sintered electrode. Niobium is more affordable.

Because the oxide layer is nicely thin, and the optionally electrode sintered has much area, such components offer more capacitance in a smaller volume than plastic film do, especially at low voltages.