Fe₂O₃/Al₂O₃ oxygen carriers improved with Mg addition were used for the chemical looping steam reforming of methane (CLSR) in a lab-scale fluidized bed reactor. The oxygen carrier with a (Mg+Fe)/Al molar ratio of 0.5 exhibited the most promising reactivity and stability as CO selectivity, CH₄ conversion, H₂/CO, and H₂ yield remained at 96%, 82%, around 2, and 0.75 mmol/g oxygen carrier, respectively, after the 15th cycle, and only the Mg–Fe–Al–O spinel appeared after 50 cycles. According to characterization, the Mg–Fe–Al interaction was the root cause of performance differences. With the increase of the Mg/Al ratio, the reacted oxygen carriers possessed a decreased Fe²⁺/Fe³⁺ and exhibited better lattice oxygen activity, but depressed the CH₄ conversion and CO selectivity during the CH₄ reduction stage. The oxygen carrier with low-lattice-oxygen activity followed the indirect mechanism with C as the intermediate product, leading to high CH₄ conversion and CO selectivity.

中文翻译：

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增强型 Fe2O3/Al2O3 载氧体用于不同 Mg 比甲烷的化学链式蒸汽重整

Fe ₂ O ₃ /Al ₂ O ₃氧载体在实验室规模的流化床反应器中用于甲烷的化学循环蒸汽重整 (CLSR)。(Mg+Fe)/Al 摩尔比为 0.5 的氧载体在 CO 选择性、CH ₄转化率、H ₂ /CO 和 H _{2方面表现出最有希望的反应性和稳定性}第 15 次循环后，产率分别保持在 96%、82%、2 和 0.75 mmol/g 左右，循环 50 次后仅出现 Mg-Fe-Al-O 尖晶石。根据表征，Mg-Fe-Al 相互作用是性能差异的根本原因。随着Mg/Al比的增加，反应后的氧载体具有降低的Fe ²⁺ /Fe ³⁺，表现出更好的晶格氧活性，但在CH ₄还原阶段降低了CH ₄转化率和CO选择性。具有低晶格氧活性的氧载体遵循以C为中间产物的间接机理，导致高CH ₄转化率和CO选择性。