Hydrogen production by copper based thermochemical water-splitting

摘要

Two-step thermochemical water-splitting by the copper based metal oxide was studied to confirm the feasibility of hydrogen production using a concentrated solar heat. The binder material Cu-ferrite was mixed with copper oxide in order to suppress the degradation of cycle capability, which is generally caused by the agglomeration of copper oxide during cyclic redox reaction. It was confirmed that the thermal reduction of CuO/CuFe_2O_4 proceeds above 1053K, while the reduced metal oxide reacts with steam below 973K. The crystal structure of Cu-ferrite was changed to metal and cation excess metal oxide during the reduction step. It was confirmed that CuO/CuFe_2O_4 had a good cycle capability during 10 redox-cycles. It is expected that CuO-Cu_2O/CuFe_2O_4 system could be a good candidate for hydrogen production by 2-step solar thermochemical water-splitting.