This thesis describes hydrogen generation from liquid hydrogen carriers such as methanol, formic acid and N-heterocycles. For this purpose, transition metal catalysts were explored based on Ru, Mn, Fe and Ni. In addition, a specific heterogeneous intermetallic nickel silicide catalyst supported on fumed silica (Aerosil® OX50) was used to promote hydrogenation/dehydrogenation of N-heterocycles. This latter system is the first heterogeneous Ni nanostructured catalyst capable of promoting reversible hydrogen storage. Furthermore, homogeneous catalysts with Ru, Me and Fe coordination centers were employed for formic acid and methanol dehydrogenations. An inventive solution of employing bi-catalytic system to improve multiple-step catalysis was proposed in case of methanol reforming.