Oliveira, FernandoSardinha, ManuelJustino Netto, Joaquim ManoelLeite, MarcoFarinha, MiguelBarreiros, Maria AlexandraAbanades, StéphaneFernandes, Jorge2025-09-192025-09-192025-07Oliveira, F. A. Costa, Sardinha, M., Netto, J. M. J., Farinha, M., Leite, M., Barreiros, M. A., Abanades, S., & Fernandes, J. C. (2025). Mechanical Performance of Ceria-Coated 3D-Printed Black Zirconia Cellular Structures After Solar Thermochemical CO/H2 Fuel Production Cycles. In: Crystals, 2025, vol. 15 (7), article 629. https://doi.org/10.3390/cryst15070629http://hdl.handle.net/10400.9/6066ABSTRACT: Solar fuels production requires developing redox active materials with porous structures able to withstand thermochemical cycles with enhanced thermal stability under concentrated solar irradiation conditions. The mechanical performance of 3D-printed, macroporous black zirconia gyroid structures, coated with redox-active ceria, was assessed for their suitability in solar thermochemical cycles for CO2 and H2O splitting. Experiments were conducted using a 1.5 kW solar furnace to supply the high-temperature concentrated heat to a windowed reaction chamber to carry out thermal redox cycling under realistic on-sun conditions. The ceria coating on ceramic structures improved the thermal stability and redox efficiency while minimizing the quantity of the redox material involved. Crushing strength measurements showed that samples not directly exposed to the concentrated solar flux retained their mechanical performance after thermal cycling (similar to 10 MPa), while those near the concentrated solar beam focus exhibited significant degradation due to thermal stresses and the formation of CexZr1-xO2 solid solutions (similar to 1.5 MPa). A Weibull modulus of 8.5 was estimated, marking the first report of such a parameter for fused filament fabrication (FFF)-manufactured black zirconia with gyroid architecture. Failure occurred via a damage accumulation mechanism at both micro- and macro-scales. These findings support the viability of ceria-coated cellular ceramics for scalable solar fuel production and highlight the need for optimized reactor designs.engSolar fuelsThermochemical cycleBlack zirconiaMaterialsElastic propertiesjournal article10.3390/cryst150706292073-4352