Kinetics of Thermal Reduction Step of Thermochemical Two-step Water Splitting Using CeO2 Particles: MASTER-plot Method for Analyzing Non-isothermal Experiments

AbstractThermochemical two-step water splitting cycle by concentrated solar heat has been studied as an energy conversion of solar energy into hydrogen energy. The thermochemical two-step water splitting cycle using metal oxide redox pair was composed of thermal reduction (T-R) step of metal oxide at higher temperature to release oxygen and, subsequent water decomposition (W-D) step of the reduced metal oxide with steam at lower temperature to produce hydrogen. Recently, cerium oxide (CeO2) is concerned as a redox pair of the thermochemical cycle for highly reactivity and cyclicity at high temperature. In this study, we focused a kinetic analysis of thermochemical two-step water splitting using cerium oxide. Various theoretical reaction models for thermal reduction (T-R) step of CeO2 particles are examined, and the appropriate reaction model for experimental results of thermogravimetric analysis was found by Master plot method. Finally, the reaction rate equation of thermal reduction is estimated