In my opinion, Ozone is the exact opposite of what we ultimately want to achieve. The opposite of Ozone is highly charged(positive) Oxygen atoms or otherwise known as "Nascent", "Ionized", or even "Monoatomic" in some cases. The same goes for Hydrogen, although, there is only one electron to deal with. The higher voltages of 15V and on up can easily ionize both O2 and H2 to their monoatomic state resulting in increased energy output from the combustion of the two gases.
Unstable gases such as these don't stay fully charged for very long. To get the most energy from the process, the nascent gases need to be used almost instantly after the disassociation occurs. It doesn't take very much time before these atoms become stable again to form O2, O3, H2, and the likes. Atoms don't like to be unstable and will do almost anything to get back to a stable state.
