We can take this from a strictly overpotential difference point of view without causing too much of a stir mr pomodoro.I'm going to refrain from blowing the anti-2lot horn from now on and be strictly going by the textbook.

You know it (-: ...try Hg/Ag amalg

Ok, started to dig around to see what I've got.  So far I have a few shiny Pt electrodes,( platenized Pt electrodes I had are misplaced but if I cant find them  in a day or two I can break a specially constructed conductivity cell  to get new ones), pure silver electrode, new glassy carbon electrode, plenty of Hg, Gold ~200mg  which I precicipated from a weak cyanide solution with dithionite.  I'm hoping to make it into a plating solution, otherwise will need to buy some 24k gold and make an electrode out of it.  I've got some palladium chloride but in solution.  I've got UHP hydrogen, Ar and oxygen. 
Since the gold will take a while to sort out, I'll probably start on the Pt/Ag.  He are a few questions to save me some work and prove your concept quicky  mr profitus.

Note, electrodes are flat, about 1cmx1cm , water is milliQ quality, deoxygenated. Room temp approx 25C. Ag will be pre treated as you described, Pt trated in strong Hcl,  then both will be made cathodes in a separate alkaline solution to reduce any surface oxides

1.What conc. KOH or NaOH is preferable.
2.What distance between electrodes?
3.If I use the shiny Pt, will it work and what pre-treatment is  needed.
4.Any stirring or keep static.
5.If I saturate liquid with H2 , leave just a few mL of H2 gas above surface and seal it then connect it to a galvanometer , do you expect it to provide a constant current? 
6.How long would the current last?
7.Do you expect any dissolution of the silver?
8. Do you expect any silver oxide?
9.Do you expect the hydrogen to be consumed?

I forgot your question number 9 mr pomodoro: this is impossible unless 1)the device is leaking(air will be sucked in).2) too much air was trapped in the device when sealed,creates a vaccuum and may pop a hole in the weakest part of the device container.3) Ag was insufficiently reduced to Ag metal prior to experiment.piping H2 through the device slowly,periodicly and out a small rubber or plastic valve is best option for those who have H2 lying around in cylinders.be sure to leak it out outside or the next time you light a cigarette will be your last.

I prefer not to have aluminate in solution. Now, I think the cell may work as follows. Pt black absorbs H2 and concentrates it. A concentration cell is formed, causing Ag to produce H2. As H2 builds up, voltage and current drop. When disconnected, H2 from Ag floats back up and voltage rises again, ready to repeat cycle. I can't see any need for catalytic   spillover!

Aluminate is totaly inert much like silicate but it can give problems if it happens to crystallize out of solution on the electrodes impeding gas access.if the NaOH sol volume is large enough and at right concentration it won't crystallize.

If I have some time I'll send photos of the proposed setup. Once we agree on a foolproof cell I will proceed. I was thinking of bonding the Pd on C to a pt electrode with silver loaded epoxy if these initial experiments go well.

PdCI2 decomposes to Pd sponge and Cl2 gas at 650 degrees C so a bunsen flame should be able to do it.ammonium chloropalladate precipitated from PdCI2 soln and a few drops ammonia soln melts then decomposes directly to sponge at low temp,300degrees