Ceria-based materials for hydrogen production by thermochemical splitting of H2O

摘要

Ceria (CeO2) is one of the most promising materials for environmental and energy applications. The high stability of this type of materials over a wide range of operating conditions rendered them suitable for other high-temperature applications such as electrolytes in solid oxide fuel cells [1]. From a chemistry point of view, the main property of Ceria is its capability to reversibly bind O2 and shift reversibly between Ce~(4+) and Ce~(3+) states under oxidizing and reducing conditions. Combining both characteristics, the ceria-based materials could be used in two-step thermochemical redox cycles for the H2 production. This technology commonly operates in two separate reduction/oxidation steps utilizing a metal oxide (MO) as a reactive intermediate. In the first step the metal oxide is reduced at elevated temperatures (generally T > 1200 °C) using high temperature solar energy.