化学链制氢中Fe2O3/LaFeO3载氧体的性能研究

采用柠檬酸络合法制备Fe₂O₃/LaFeO₃复合氧化物，将该氧化物作为化学链制氢过程的载氧体，在反应温度为900 ℃、常压下，对Fe₂O₃/CH₄（剂烷比）、进水量、金属负载量进行了考察。结果表明，剂烷比为2：1、进水量为0.1 mL、质量分数15%Fe时载氧体性能最好，甲烷转化率达到60%，单次循环氢气产量为45 mL。将该评价结果与XRD和H₂-TPR表征结果进行关联发现，反应过程的活性位不是金属氧化物，而是吸附氧，而且吸附氧越容易还原，甲烷转化率和氢气产量越高。通过连续60次还原-氧化循环发现，该载氧体上甲烷转化率和氢气产量比较稳定，循环后仍然保持钙钛矿结构。

Performance of Fe2O3/LaFeO3 as oxygen carrier in chemical-looping hydrogen generation

Fe₂O₃/LaFeO₃ was prepared by citric acid complexation method and used as oxygen carrier in chemical-looping hydrogen generation; the effect of Fe₂O₃/CH₄ ratio, stream amount and metal loading on the performance of Fe₂O₃/LaFeO₃ as oxygen carrier at 900 ℃ and atmospheric pressure were investigated. The results showed that the oxygen carrier performs best with CH₄ conversion of 60% and single-loop H₂ output of 45 mL, when the ratio of Fe₂O₃/CH₄, stream input and Fe loading are 2, 0.1 mL, 15%, respectively. The XRD and H₂-TPR results suggest that the active site is the adsorbed oxygen rather than metal oxide; the easier for the reduction of the adsorbed oxygen, the higher are the conversion of CH₄ and the output of H₂. Moreover, the oxygen carrier is still in perovskite structure and CH₄ conversion and H₂ output remain stable even after 60 cycles.