What product of fuel cells would be more beneficial to space missions than that of other fuels?

Fuel cells produce electricity through the electrochemical reaction of hydrogen and oxygen, generating only water and heat as byproducts. This is particularly beneficial for space missions, as the water produced can be recycled for drinking or used in life support systems, minimizing the need to carry additional supplies. Additionally, fuel cells are efficient and can operate in the vacuum of space, providing a reliable power source for long-duration missions without the emissions or residues associated with conventional fuels.