KARPEN PILE

[profitis]

@pomodoro let's look at the big picture: if you seal it properly or just continously stream in hydrogen through a valve what can burn the H2.nothing.zilch.zero. Only textbook catalyst spillover will take place.you said you have already got platinized platinum,thats a good start and will do instead of palladium.make sure that it is pitch black for maximum surface area.take your silver foil and a carbon rod and anodize your silver for a few seconds in NaOH soln to blacken it with Ag2O surface then cathodize it back to Ag  until you see H2 bubbles stream.the Ag foil will now have massive surface area and will be grey in colour. Use silver or gold wire on both Pt and Ag as leads out of your spillover device bulb as these metals do not leak H2.you may use copper wire on both for this test  but use it thin and try not to get it wet during the final measurements.I'm not sure wether your Pt electrode is naked or encased in glass in which case you will have to stopcock seal adequetly using silicone grease.you cannot afford to have the slightest leak-hole otherwise air gets into our test device. Its highly advantageous if your lab has bottled H2 at hand as opposed to the effort of making your own H2.your Pt should just touch the electrolyte as it must have exposure to H2 and your Ag should be half or fully submerged.use 0.5 to 1M NaOH.

[profitis]

Current should be in the 300micro-2milliamp(or more?) range for a square cm heavily platinized Pt and treated Ag under pure H2. It will be 0.3-0.5 volt at total rest.it will give a quick burst of charge everytime you short it and after the first few bursts it will reach its steady power value which will be its permanent capacity provided no air gets in there.discharge it for a second,allow a few seconds for recharge.discharge it for a minute,allow a few minutes for recharge.its like a self-charging redox cap.

[pomodoro]

Ok, after the karpen I shall have a look at this sealed hydrogen cell. Please lets focus on Karpen for now and start another thread later on the hydrogen spillover cell.

Back to Karpen and standard electrochem, I have decided to individually test each electrode in 1M Sulfuric acid, in oxygenated and deoxyenated enviroments. 

Anodic and cathodic scans will be run about E_corr just as is done for any corrosion tests.
Initially other metals known to corrode such as Iron and Copper will be tested and the plots compared to the gold and platinum.  These Tafel plots will be used in an Evans diagram to show  the effect of coupling the Pt to the Au.   
The first question I want answered is 'do any of these noble metals actually corrode?' the anodic scan could provide answers. As the metal is forced more positive, and if the  current does increase, the electrons must come from some oxidation reaction at the electrode.  If the voltage is kept below the oxidation of water to oxygen, then electrons can only be created by the oxidation of the metal.

Does anyone disagree with this, and if so, why exactly?

[profitis]

If we can accomplish something with the hydrogen bomb then this thread and even website takes on a historical event @pomodoro.we will be the first live internet interactive to slamdunk a macroscopic 2lot violation,if you can get hold of palladium chloride we can take this thing into the 2-10 milliamp/cm2 range.your enrique fermi and I'm oppenheimer lol. Ok.. let's slamdunk the smallfry first..an underpotential on Au or Pt foil is going to liberate oxygen gas yes because polarization builds up from infinite nernst dilution of oxygen gas/cm2 on your electrodes up til full saturation of O2 coverage/cm2. So that is no way to look for corrosion which is why I'm suggesting speeding up corrosion on a Pt/Au linked couple by boiling.both Au and Pt are used in the most highly sensitive O2sensors and if corrosion current was an issue for example in seawater then these highly sensitive instruments would have no value for O2 potential calibration.

[profitis]

I want to suggest throwing the gold away and using TWO Pt foils for the present microamp range oxygen karpen tests @pomodoro,what do you say...karpen used identical electrodes in figure 2 from his patent application.