Thermodynamic Analysis of Two-Step Solar Water Splitting With Mixed Iron Oxides

Exploring the theoretical potential and process conditions for two-step solar water splitting

Abstract

A two-step thermochemical cycle for solar production ofhydrogen from water has been developed and investigated. It is based on metaloxide redox pair systems, which can split water molecules by abstracting oxygenatoms and reversibly incorporating them into their lattice. After successfulexperimental demonstration of several cycles of alternating hydrogen and oxygenproduction, the present work describes a thermodynamic study aiming at theimprovement of process conditions and at the evaluation of the theoreticalpotential of the process. In order to evaluate the maximum hydrogen productionpotential of a coating material, theoretical considerations based onthermodynamic laws and properties are useful and faster than actual tests.