There was an American inventor who created a method to retrofit all cars so they could run on water.
The man was poisoned and all his work was discredited.
Read hour own sources -
Theory violation: First law of thermodynamics
The Meyer Fuel Cell was a sham, simple electrolysis disguised as new tech, and Meyer himself lost a lawsuit by investors charging him with fraud.
This isn't to say that splitting water can't work; there was an advance last week using metal nanoparticles with the H2 driving a fuel cell, but it is VERY far from practicality. Fuel cells are very expensive. That and processing the nanoparticles blows up the economics.