Hydrogen finds a variety of uses in chemical processes.
Haber's process is used for ammonia synthesis.
N2+3H2→2NH3
Cold combustion refers to the process through which water is slowly produced in space shuttles.
2H2 (g)+O2 (g)→2H2O (l)
Hydrogenation refers to the addition of H2 gas over a double or triple bond to yield a single bond, between two carbon atoms, in an organic compound.
C2H4+H2Ni/Pd−−−−→C2H6