Splitting CO₂ with a thermochemical redox cycle utilizes the entire solar spectrum and provides a favorable path to the synthesis of solar fuels at high rates and efficiencies. However, the temperature/pressure swing commonly applied between reduction and oxidation steps incurs irreversible energy losses and severe material stresses. Here, we experimentally demonstrate for the first time the single-step continuous splitting of CO₂ into separate streams of CO and O₂ under steady-state isothermal/isobaric conditions. This is accomplished using a solar-driven ceria membrane reactor conducting oxygen ions, electrons, and vacancies induced by the oxygen chemical potential gradient. Guided by the limitations imposed by thermodynamic equilibrium of CO₂ thermolysis, we operated the solar reactor at 1,600°C, 3·10⁻⁶ bar $p_{{\text{O}}_2}$ and 3,500 suns radiation, yielding total selectivity of CO₂ to CO + ½O₂ with a conversion rate of 0.024 μmol·s⁻¹ per cm² membrane. The dynamics of the oxygen vacancy exchange, tracked by GC and XPS, further validated stable fuel production.

通过热化学氧化还原循环分解CO ₂利用整个太阳光谱，并为高速率和高效率合成太阳能燃料提供了有利的途径。然而，通常在还原和氧化步骤之间施加的温度/压力波动会导致不可逆的能量损失和严重的材料应力。在这里，我们首次通过实验证明了在稳态等温/等压条件下，CO ₂单步连续分裂成单独的CO 和O ₂流。这是通过使用太阳能驱动的氧化铈膜反应器来传导氧离子、电子和由氧化学势梯度引起的空位来实现的。在CO ₂热解的热力学平衡所施加的限制的指导下，我们在1,600°C、3·10 ^-6 bar 的条件下运行太阳能反应器${\mathrm{<span\; data-immersive-translate-walked="59631c48-bdbc-42e7-8f51-19de69f64745">p</span>}}_{{\text{<span data-immersive-translate-walked="59631c48-bdbc-42e7-8f51-19de69f64745">氧</span>}}_{\mathrm{<span\; data-immersive-translate-walked="59631c48-bdbc-42e7-8f51-19de69f64745">2</span>}}}$和3,500个太阳辐射，产生CO ₂到CO + ½O ₂的总选择性，转化率为每cm ²膜0.024 μmol·s ^-1 。通过 GC 和 XPS 跟踪的氧空位交换动态进一步验证了稳定的燃料生产。