Repurposing of CO₂ to valuable hydrocarbons is crucial for energy security and a balanced carbon cycle. Reverse water gas shift chemical looping (RWGS-CL) is capable of efficient CO₂ to CO conversion at a low temperature of ∼600 °C with unprecedented rates using the La_0.75Sr_0.25FeO₃ (LSF) perovskite-type oxide amalgamated with silica. The LSF/SiO₂ composite (25% LSF by mass) promotes a notable extent of oxygen vacancies in the active phase, a key parameter for CO₂ conversion. In each of eight RWGS-CL cycles, CO generation yields of LSF/SiO₂ surpass those of LSF alone by about 200%, producing 2.6 mmol of CO g_LSF^–1 at a peak rate of 0.8 mmol CO g_LSF^–1 min^–1. This significant improvement is concomitant with a decreased average LSF crystallite size retained at these low thermochemical reaction temperatures. Evidence of this enhancement points to perovskite particle size reduction by silica, lattice strain induced by the support, and curtailed quantities of secondary phases that limit accessibility to active surfaces. In this contribution, an appropriate stable platform for improving earth abundancy in perovskite-based redox materials is demonstrated for industrial-scale low-temperature CO₂ thermochemical conversion.

中文翻译：

---

二氧化硅负载的钙钛矿氧化物在低温下增强了将CO ₂转化为CO的能力

将CO ₂重新转化为有价值的碳氢化合物对于能源安全和平衡碳循环至关重要。反向水煤气变换化学循环（RWGS-CL）能够在约600°C的低温下以前所未有的速率使用La _0.75 Sr _0.25 FeO ₃（LSF）钙钛矿型氧化物与硅酸盐混合而高效地将CO ₂转化为CO 。LSF / SiO ₂复合材料（质量含量为25％LSF）可显着提高活性相中氧空位的程度，而空位是CO ₂转化的关键参数。在八个RWGS-CL循环中的每个循环中，LSF / SiO _2的CO生成量超过单独的LSF约200％，生成2.6 mmol CO g _LSF^–1的峰值速率为0.8 mmol CO g _LSF ^–1分钟^–1。在这些低的热化学反应温度下，伴随着平均LSF晶粒尺寸的减小，这一重大改进是伴随而来的。这种增强的证据表明，二氧化硅会降低钙钛矿的粒径，载体引起的晶格应变，以及减少限制活性表面可及性的第二相的数量。在此贡献中，证明了用于工业化低温CO ₂热化学转化的合适稳定平台，可改善钙钛矿基氧化还原材料中的地球丰度。