Abstract: The subject of the invention is a process for the hydrogenation of hydrogen carbonate in an aqueous reaction system, where the process ensures that the hydrogen carbonate, hydrogen and catalyst come into contact with each other while carbon dioxide is present in the gas space. In this phase of the process, formate is produced. The subject of the invention is also a process for the catalytic decomposition of formate in an aqueous reaction system and the hydrogenation of hydrogen carbonate produced in the same reaction system according to the invention, where the reactants and the reaction products are formed in a reversible reaction cycle using the reaction system according to the invention, and this reaction cycle is repeated in the required number of times. In the mentioned formate mg decomposition process, the formate and the catalyst come into contact, so that hydrogen gas and hydrogen carbonate free of COX by-products are produced as the product of the reaction.

Abstract: The subject of the invention is a process for the hydrogenation of hydrogen carbonate in an aqueous reaction system, where the process ensures that the hydrogen carbonate, hydrogen and catalyst come into contact with each other while carbon dioxide is present in the gas space. In this phase of the process, formate is produced. The subject of the invention is also a process for the catalytic decomposition of formate in an aqueous reaction system and the hydrogenation of hydrogen carbonate produced in the same reaction system according to the invention, where the reactants and the reaction products are formed in a reversible reaction cycle using the reaction system according to the invention, and this reaction cycle is repeated in the required number of times. In the mentioned formate mg decomposition process, the formate and the catalyst come into contact, so that hydrogen gas and hydrogen carbonate free of COX by-products are produced as the product of the reaction.

Abstract: The invention relates to a catalyst according to the formula IrCl(cod)(NHC)]+nP (n=2, 3 or 4), or [Ir(cod)(NHC)(P)]+nP (n=1, 2 or 3), which is suitable to decompose formates in an aqueous reaction system, and for the production of hydrogen gas free of COx or hydrogenation of hydrogen carbonates, wherein Ir means iridium; Cl means chloro; cod means 1,5-cyclooctadiene; NHC means N-heterocyclic carbene, preferably 1-R-3-methylimidasolium chloride, wherein R means C1 to C5 alkyl and P means 1,3,5-triaza-7-phosphaadamantane (pta), monosulphonated triphenilphosphine (mtppms), trisulphonated triphenylphosphine (mtppts), or tetrasulphonated diphenylphosphynopropane (dpppts). Furthermore, the invention relates to a process for the preparation of the catalyst according to the invention.