Well I can tell you this.
Impedance matching is used to get the maximum power to flow to the load.
Power is Voltage X Current and is measured in watts,
Power is not voltage but a combination of current and voltage.
Impedance or Voltage Bridging is used to get the maximum voltage to flow to the load.
If your using Brute force electrolysis you may have something to gain by impedance matching, but when your going for voltage I believe impedance bridging may be more important. I have not done anything to prove this out but am merly just citing what i have read in the past.
I know steve meyer has a patent which uses impedance matching circuits, so it may be of importance, but he was also using alternators in his setup which produce current as well, so I cannot draw a conclusion on what exactly he was doing there.
Sources:
http://en.wikipedia.org/wiki/Impedance_matchinghttp://en.wikipedia.org/wiki/Impedance_bridging