Bob Lazars car used 6Li (lithium-6) H (hydride) for H1 storage which he created in his own particle accelerator as you cannot easily purchase that material because it has to do with nuclear weapons iirc.
Basically it stores the hydrogen and then when heat is applied it releases the hydrogen which is then used in the engine.
This is the video explaining it better than i can
enter text
Bob Lazars car used 6Li (lithium-6) H (hydride) for H1 storage which he created in his own particle accelerator as you cannot easily purchase that material because it has to do with nuclear weapons iirc.
Basically it stores the hydrogen and then when heat is applied it releases the hydrogen which is then used in the engine.
This is the video explaining it better than i can enter text