The closure cap (1) is capable of generating molecular hydrogen from a chemical reaction with water, and can be used for closing a container and for scavenging oxygen. The cap (1) comprises a shell (10), an active layer (11) that is capable of chemically reacting with water and generating molecular hydrogen, and a liner (12) that is permeable to water vapour and to molecular hydrogen said active layer (11) has an inner face (11a), an outer face (11b) and a circumferential edge (11c) the shell (10) comprises a housing and the active layer (11) is entirely contained in said housing the outer face (11b) and the circumferential edge (11c) of the active layer (11) are in contact with the shell (10) and are bonded to the shell (10) the liner (12) is closing said housing and is bonded to the shell (10) on the whole periphery of the active layer (11) and to the inner face (11a) of the active layer (11).
