Chemical looping partial oxidation of methane using a sole CO₂ oxidant (CL-POM-CO₂) is an emerging technology for synthesis gas generation and CO₂ utilization, which is highly dependent on an oxygen carrier (OC). In this work, Fe-substituted La-hexaaluminate as the OC was found to exhibit good reactivity and stability during 50 periodic CH₄/CO₂ redox cycles due to the formation of magnetoplumbite La-hexaaluminate structure with the introduction of La. Deeper reduction for synthesis gas generation did not destroy the La-hexaaluminate structure via a charge compensation mechanism, which increased CH₄ reactivity and further improved CO₂ utilization under subsequent re-oxidation. In the La-hexaaluminate structure, O₆-Fe³⁺(Oh) was highly active for the total oxidation of methane, while O₅-Fe³⁺(Tr) and O₄-Fe³⁺(Th) selectively oxidized CH₄ to synthesis gas. The sole CO₂ oxidant only selectively recovered O₅-Fe³⁺(Tr) and O₄-Fe³⁺(Th), and thus is more favorable for improving synthesis gas selectivity than O₂/air, which offers an attractive opportunity for CO₂ utilization. © 2017 American Institute of Chemical Engineers AIChE J, 2017

中文翻译：

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La-六铝酸盐，用于以CO2为唯一氧化剂的甲烷化学循环部分氧化制取合成气

使用唯一的CO ₂氧化剂（CL-POM-CO ₂）对甲烷进行化学循环部分氧化是一种新兴的生产合成气和利用CO _2的技术，该技术高度依赖于氧载体（OC）。在这项工作中，发现铁取代的La-六铝酸盐作为OC在50个周期性的CH ₄ / CO ₂氧化还原循环中表现出良好的反应性和稳定性，这是由于引入La形成了磁铅石La-六铝酸盐结构。合成气的产生并未通过电荷补偿机制破坏La-六铝酸盐的结构，从而增加了CH _4的反应性并进一步改善了CO _2。在随后的再氧化过程中的利用率。在六铝酸镧结构中，O ₆ -Fe ³⁺（Oh）对甲烷的总氧化具有高活性，而O ₅ -Fe ³⁺（Tr）和O ₄ -Fe ³⁺（Th）选择性氧化CH ₄合成气。唯一的CO ₂氧化剂仅选择性地回收了O ₅ -Fe ³⁺（Tr）和O ₄ -Fe ³⁺（Th），因此比O ₂ /空气更有利于提高合成气的选择性，为O ₂ /空气提供了诱人的机会。一氧化碳₂利用率。©2017美国化学工程师学会AIChE J，2017