Engine. (see Rex)

-The hydrogen can be used directly as fuel in a rocket engine, turbo-rocket, etc. or through fuel cells.

-It's like in the case of Gerard Thévenot, an engineer who has coupled his hydrogen cell and electric motor on a "trike" or a motorized delta, the Helite model of La Mouette.

-It has a tank with 5 liters of hydrogen to power a battery of 3 cells that generate a total of 7 kW.

“Motor with hydrogen cells”

-The rocket engines use liquid hydrogen that combines with liquid oxygen generally.

-The Germans used hydrogen peroxide in their first engines. Subsequently, the allies made tests with the same fuel, as is the case with Allison.

“Test of an Allison rocket engine” (PiP)