How to construct twp-electrode system in hydrogen evolution reaction? In zinc air battery system, researchers usually construct a two-electrode system with a zinc metal and the catalyst he made as the working electrode for oxygen evolution and oxygen reduction reaction. So how can we build the similar system in the hydrogen evolution reaction? Can anyone recommend some paper?
Any acid on metal generates hydrogen as the metal is consumed. If you want to generate electricity from the same cell, then one electrode is made of graphite and is not consumed. Hydrogen evolves from the metal, but the acid gets diluted with metal salt and must be replenished eventually.
Zinc metal is used because of low cost.
If your goal is not to consume one of the electrodes, I would advise against using zinc. Depending on the pH you want to operate at, how expensive the components can be, and how efficient the system needs to be, there are many options:
Platinum metal is very efficient, especially under acidic conditions, and it can support extremely high current densities--but it's expensive.
Under basic conditions, stainless steel will be the cheapest option, but copper, nickel and cobalt all work well.
There are also catalysts for HER, such as chalcogenides or phosphdes of transition metals, which may be grown or deposited on a working electrode.