Gas-phase vs. material-kinetic limits on the redox response of nonstoichiometric oxides.

Cerium dioxide, CeO, remains one of the most attractive materials under consideration for solar-driven thermochemical production of chemical fuels. Understanding the rate-limiting factors in fuel production is essential for maximizing the efficacy of the thermochemical process. The rate of response is measured here via electrical conductance relaxation methods using porous ceria structures with architectural features typical of those employed in solar reactors.