KARPEN PILE

[pomodoro]

BTW Im not going to do any tests if they require electrolysis,  these will of course show hydrogen overpotentials!

I've just unshorted the cell, after 18 hours  and will report hourly emf of cell.  I'll keep modifying this post rather than creating new one, so keep coming back here for the updates.

negative value  means C is more negative than the Pd/Pt

Time   EMF
0 -    0mV
1hr    -1mV
2hrs   -8mV
3hrs   -12mV

Voltage does change very slowly. Decided to end experiment here, now passing UHP hydrogen through exacltly same setup.  Cell is shorted out

[pomodoro]

Some positive news., I've been going through text books and found a chapter that indicates that a Pt /C cell CAN act as a power source albeit at a very low current.  Have a look at the attachment, Pic A11, is the cell as a power source, at zero volts (shorted) there is a miniscule current flowing.    This cell is deaerated, however so the rest voltage is somewhere between the two water redox couples, any oxygen  such as in  the cell I'm testing, would shift both to the same potential of the anode.  Hydrogen would have do the same, but there will be a potential difference.    Ummm, looks like hydrogen will be pumped in soon.

[MarkE]

That is a good find.

[profitis]

This cell setup pomodoro.this cell I have done hundreds of times.it has a most stubbornly persistent oxygen potential difference and 50-100microamp/cm2.use NaOH or ammonium sulfate solution.both electrodes are same metal so it proves beyond all doubt a very definite participation of oxygen gas spillover.

[pomodoro]

Thats  easy to do. I need to prepare platinizing solution,  so I can't do it straight away, but soon..

Right now UHP hydrogen is being used in exactly the same cell I tested with Air,  nothing was moved. Keep an eye on that post as I update voltages in about 16 or so hours.