This work addresses the solar-driven thermochemical production of CO and O₂ from two-step CO₂-splitting cycles, using both ceria granules prepared from cork templates (CG) and ceria foams from polyurethane templates (CF). These materials were cycled in a high-temperature indirectly-irradiated solar tubular reactor using a temperature-swing process. Samples were typically reduced at 1400 °C using concentrated solar power as a heating source and subsequently oxidised with CO₂ between 1000–1200 °C. On average, CO production yields for CG were two times higher than for CF, indicating that the morphology of this three-dimensionally ordered macroporous (3-DOM) CeO₂ improves the reaction kinetics. Their performance stability was demonstrated by conducting 11 cycles under solar irradiation conditions. Slightly increasing the reduction temperature strongly enhanced the reduction extent, and thus the CO production yield (reaching about 0.2 mmol g⁻¹ after reduction at 1450 °C in inert gas), while decreasing the oxidation temperature mainly improved the CO production rate (up to 1.43 μmol s⁻¹ g⁻¹ at 1000 °C). Characterisation of the 3-DOM structure, by means of XRD and SEM, provided insights into the reactivity behaviour of the developed materials. The pre-sintered ceria granules retained their structure after cycling. The fact that the mean cell size of CG is smaller (at least one order of magnitude) than that of CF suggests that its exposed surfaces enhanced reaction rates by a factor of two. Moreover, the maximum fuel production rate of CG was roughly three times greater than that reported previously for a ceria reticulated porous foam with dual-scale porosity.

这项工作解决了由两步CO ₂分解循环产生的太阳能驱动的CO和O _2的热化学生产，使用了从软木模板（CG）制备的二氧化铈颗粒和从聚氨酯模板（CF）制备的二氧化铈泡沫。使用变温工艺在高温间接辐射的太阳能管式反应器中循环这些材料。通常，使用聚光太阳能作为加热源在1400°C下还原样品，然后在1000-1200°C之间用CO ₂氧化。平均而言，CG的CO产量比CF的高两倍，这表明这种三维有序大孔（3-DOM）CeO ₂的形态改善反应动力学。通过在太阳辐射条件下进行11次循环证明了它们的性能稳定性。略微提高还原温度会大大提高还原程度，因此，CO的产率（在惰性气体中于1450°C还原后达到约0.2 mmol g ^-1），而降低氧化温度则主要提高了CO的产率（最高1.43μmols ^-1克^-1在1000°C时）。通过XRD和SEM表征3-DOM结构，为开发材料的反应性行为提供了见识。循环后，预烧结的二氧化铈颗粒保持其结构。CG的平均细胞大小小于CF的平均细胞大小（至少一个数量级）这一事实表明，其暴露的表面将反应速率提高了两倍。此外，CG的最大燃料生产率大约是以前报道的具有双尺度孔隙率的二氧化铈网状多孔泡沫的三倍。