H2 must be stored at more elevated pressures with respect to hydrocarbon gas fuels to achieve similar energy density. This creates higher requirements on pressure vessels and containment structures, both in terms of building materials’ strength and assembly weight. Moreover, H2 is known to degrade materials’ properties; in particular, in the case of metals, molecular H2 can dissociate at the metal surface, resulting in atomic H2 to diffuse into the bulk. This can eventually degrade the material’s properties, especially the ductility and fracture resistance.