Fuel Cells
In a fuel cell gases flow into porous chambers impregnated with cataylsts.  These gas chambers are immersed in a KOH or NaOH solution.
Anode reaction:      H2 + 2 OH-1  ---->  2 H2O  +  2 e-1
Cathode reaction:   O2  +  2 H2O  +  4 e-1  ----->  4 OH-1
The reaction requires a continuous flow of H2 and O2 at 250oC and 5000 kPa pressure.