Hydrogen gas must be bubbled into the solution so that they are able to oxidize by loosing electrons which they can't just in air. Platinum electrode needs not be cleaned. Potential depends upon concentration of hydrogen, by "Nerst" equation. If hydrogen was there or not, current can never be lost, speed of process is kinetics and in no way related to thermodynamics, Cost, rubbish.

Hydrogen gas must be bubbled into the solution so that it is able to oxidize by losing electrons which they can't just in air. Platinum electrode need not be cleaned. Potential depends upon concentration of hydrogen, by "Nernst" equation. If hydrogen was there or not, current can never be lost, speed of process is kinetics and in no way related to thermodynamics. Cost, rubbish.