Hydrogen production by water splitting with Mn3-xCoxO4 mixed oxides thermochemical cycles: A thermodynamic analysis

Abstract The high temperature required for hydrogen production by solar driven thermochemical cycles is a critical factor hindering full-scale applications. The thermochemical cycle based on Mn3O4/MnO redox pair is one of the most studied despite the high operating temperature required for complete de reduction step (1623–1723 K). The combination of Mn3O4 with Co3O4, a metal oxide with lower reduction temperature than Mn3O4 that cannot be used for hydrogen production due to thermodynamic limitations, is presented as a way to decrease significantly the energy demand of the cycle. In this work, a complete thermodynamic study of thermochemical cycles with different Mn/Co mixed oxides (Mn3-xCoxO4, 0.9