15　Thermochemical two-step water-splitting cycle with high-entropy metal oxides

Abstract

A two-step thermochemical water splitting cycle using a redox system of a metal oxide is one of the promising processes for converting concentrated solar high-temperature heat into clean hydrogen in sun-belt regions. Recently, Zhai et al. have shown that a poly cation oxide (Mg_0.25Ni_0.25Co_0.25Fe_0.25O_x or MNCFO) or a high entropy iron oxide reveals a greater reactivity for the two-step water splitting cycle than the benchmark ceria. In this work, we have discovered that Mn-containing high-entropy iron oxides have much greater reactivities than ceria and the MNCFO for the lower temperature cycles below 1200-1400˚C.