Implementation of the solar thermochemical ceria redox cycle to split water and carbon dioxide depends in part on the morphological stability of a porous ceria substrate and the ability to acquire porous substrate in high volume. Here we evaluate the evolution of morphology and fuel production of ceria particles formed of fibers in a commercially relevant manufacturing process. The particles are evaluated over 1000 CO2-splitting cycles (56 h) at 1773 K followed by sixteen temperature-swing cycles (5.7 h) with oxidation at 1073 K. New particles are 78% porous with a specific surface area of 0.14 m2 g−1 and a grain size of 3.7 μm. During isothermal cycling, the morphology stabilized after 500 cycles (28 h) to 73% porosity, a surface face 0.08 m2 g−1 and a grain size of 8 μm. The stabilized particles retained 89% of the peak cycle average rate of CO production. During temperature-swing cycling, the specific surface area decreased to 0.06 m2 g−1. The mass-produced fibrous structures have adequately stable morphologies to produce fuel production performance similar to less scalable (lab-scale) ceria structures of similar pre-cycling surface area.
Bibliographical noteFunding Information:
The financial support by the U.S. Department of Energy’s Advanced Research Projects Agency—Energy (DOE ARPA-E, award no. DE-AR0000182) to the University of Minnesota, and by the University of Minnesota Initiative for Renewable Energy and the Environment (IREE, grant no. RM-0001-12 ) is gratefully acknowledged.
- Cerium dioxide
- Solar thermochemical