There are fuel systems that work with an aluminium alloy, e.g. with gallium. When water is added, hydrogen is generated. As a waste product, aluminium oxide is produced, which must be recyled using energy.

https://www.purdue.edu/newsroom/research/2011/110503WoodallWater.html

https://spectrum.ieee.org/hydrogen-on-tap-device-trucks-fuel-efficient-vehicles

https://phys.org/news/2007-05-hydrogen-aluminum-alloy-fuel-cells.html

https://phys.org/news/2005-10-car-fuel.html

Regards,

Joachim

Water is not a fuel in the traditional sense since it does not contain any energy that can be released through combustion. However, water can be used as a source of hydrogen, which is a fuel that can be used in various applications, including powering vehicles and generating electricity.

To use water as a fuel, a process called electrolysis is typically used to split water molecules into hydrogen and oxygen gases. This process requires an external source of energy, usually electricity, to be supplied to an electrolysis cell to initiate the reaction.

The resulting hydrogen gas can then be used as a fuel by being burned in an internal combustion engine or used in a fuel cell to generate electricity. In these applications, hydrogen is often seen as a cleaner alternative to traditional fossil fuels since it does not produce carbon emissions when burned, only water vapor.

However, there are several challenges to using hydrogen as a fuel, including the high cost of producing hydrogen through electrolysis and the lack of infrastructure for distributing and storing hydrogen on a large scale. Additionally, hydrogen can be dangerous to handle since it is highly flammable and can ignite at very low concentrations in air.

In summary, while water cannot be used as a fuel directly, the hydrogen that can be extracted from it can be used as a clean alternative to traditional fossil fuels. However, several technical and economic challenges need to be overcome to make the widespread use of hydrogen as a fuel a reality.