NOVELTY - In the reversible storage of hydrogen, an inorganic as a potassium carbonate and/or potassium hydrogen carbonate is supplied in an aqueous solution (2) in reactor vessel (1). The inorganic is catalytically treated in the aqueous solution by catalytically activated nickel electrodes contained in the reactor vessel. The catalysts are a ZnO or a ZnO/TiO2. Oxygen is split from carbon dioxide by introducing a current via the electrodes with 2.5 V under simultaneous hydrogenation of the inorganic at the surface of the electrodes to form potassium formate.    USE - The invention deals with reversible storage of hydrogen.    ADVANTAGE - Simple and more economical reversible storage of hydrogen in higher density. The handling of the liquid storage and/or storage material and its starting materials are simple and environmentally compatible.    DETAILED DESCRIPTION - In the reversible storage of hydrogen, an inorganic as a potassium carbonate and/or potassium hydrogen carbonate is supplied in an aqueous solution (2) in reactor vessel (1). The inorganic is catalytically treated in the aqueous solution by catalytically activated nickel electrodes contained in the reactor vessel.    The catalysts are a ZnO or a ZnO/TiO2.    Oxygen is split from carbon dioxide by introducing a current via the electrodes with 2.5 V under simultaneous hydrogenation of the inorganic at the surface of the electrodes to form potassium formate. The hydrogenation takes place in the reactor vessel by supplying gaseous hydrogen. The produced inorganic is stored in aqueous solution in the same reactor or in a storage container (20).    The potassium formate is converted into formic acid and methanol by further hydrogenation under adding of CO2. In the place of potassium formate, the process produces a different hydrocarbon. The emerging gas flows into a container through a KOH or a K2CO3-solution. The CO2-proportion is removed from the gas and forms K2CO3 and/or K2HCO3 and the remaining hydrogen is removed by a discharge pipe (18).    The potassium formate is catalytically dissociated or split in a container with platinum or palladium-catalysts, and the hydrogen (4) is released. The potassium formate or formic acid or mixtures from it is added in aqueous solution. The hydrogen and the inorganic are released during the process and a renewed catalytic treatment and hydrogenation are carried out after discharge of the hydrogen. The released hydrogen is supplied to a fuel cell and/or a hydrogen engine or other device, which releases energy from hydrogen.    A membrane from non-conducting, ion-permeable material both sides coated with silver is arranged in the storage. A voltage is measured by connecting the coatings with contacts during the discharging and/or the oxidation of potassium formate to potassium hydrogen carbonate. The membrane is a non porous and is used as wall element inserted into the container for chambers formation.    The anode of the Ni-electrode arrangement is assigned in the chamber, and the corresponding cathode and the silver coating are present in another chamber. The coating layer in the other chamber forms the negative pole and the other coating layer in an additional chamber forms the positive pole.    DESCRIPTION OF DRAWING(S) - The figure shows a fundamental construction for procedure for reversible storage of hydrogen:    Reaction vessel; (1)    Aqueous solution; (2)    Hydrogen; (4)    Supply pipe; (6)    Discharge pipe; (18)    Storage container. (20)