The Effects of Morphology on the Oxidation of Ceria by Water and Carbon Dioxide

The oxidation of three-dimensionally ordered macroporous (3DOM) CeO2 (ceria) by H2O and CO2 at 1100 K is presented in comparison to the oxidation of nonordered mesoporous and sintered, low porosity ceria. 3DOM ceria, which features interconnected and ordered pores, increases the maximum H-2 and CO production rates over the low porosity ceria by 125% and 260%, respectively, and increases the maximum H-2 and CO production rates over the nonordered mesoporous cerium oxide by 75% and 175%, respectively. The increase in the kinetics of H2O and CO2 splitting with 3DOM ceria is attributed to its enhanced specific surface area and to its interconnected pore system that facilitates the transport of reacting species to and from oxidation sites. [DOI: 10.1115/1.4005119]