Electrolysis has been considered to be an interesting research topic in recent decades. With the important advances in controllable solid-state semiconductor devices, it has become relatively simple to design power converters with high voltage and high frequency outputs. In this paper, high-voltage pulsed electrolysis is considered with optimisation of the frequency and voltage as well as the separation of the electrodes for different electrolytes. This paper also describes the use of pulsed plasmolysis, giving a new way to decompose water for the production of hydrogen.