Magnetite with high content of Fe₃O₄ is a promising low-cost oxygen carrier candidate for co-production of syngas and pure hydrogen via chemical looping steam reforming (CLSR). The present work investigated the effect of ultrasonic treatment on the structure of magnetite by using X-ray diffraction (XRD) technology and Energy Dispersive Spectrometer (EDS) mapping technologies, and the results were correlated to the activity of magnetite oxygen carrier for selective oxidation of methane and water splitting. The evolutions of phases and compositions of magnetite during the reaction with methane were also studied to discuss the reaction mechanism. The results showed that ultrasonic treatment significantly improves the activity of magnetite oxygen carrier for methane selective oxidation by destroying the dense structure of magnetite and promoting the interdiffusion of different elements (e.g., Fe, Al and Mg) that could enhance the interaction between the active species (Fe oxides) and inert spaces (Al and Mg oxides). The syngas production increased from 10.29 to 13.15 mmol/g and hydrogen production increased from 4.93 to 5.43 mmol/g after the ultrasonic treatment, and both the produced hydrogen and syngas show high purity (ca. 96.5% for syngas and ca. 98.9% for H₂). During the reaction between methane and magnetite, the reduction of iron oxides firstly occurred in the boundary between the iron oxides and the inert components (e.g., Al/Mg oxides), which then diffused to the adjacent areas and created numbers of smaller Fe islands. The channels around the Fe islands provide pathways for methane diffusion, improving the further reduction of oxygen carrier.

磁铁矿中Fe ₃ O ₄含量高是通过化学循环蒸汽重整（CLSR）联产合成气和纯氢的有前途的低成本氧气载体候选产品。本研究利用X射线衍射（XRD）技术和能量色散谱仪（EDS）作图技术研究了超声处理对磁铁矿结构的影响，并将结果与​​磁铁矿氧载体选择性氧化铁的活性相关。甲烷和水分解。还研究了与甲烷反应期间磁铁矿的相和组成的演变，以探讨反应机理。结果表明，超声处理通过破坏磁铁矿的致密结构并促进不同元素（例如铁，铝和镁）的相互扩散，可以显着提高磁铁矿氧载体的甲烷选择性氧化活性，从而增强活性物质之间的相互作用。 （Fe氧化物）和惰性空间（Al和Mg氧化物）。超声处理后，合成气产量从10.29增加到13.15 mmol / g，氢气产量从4.93增加到5.43 mmol / g，并且所产生的氢气和合成气均显示出高纯度（合成气约96.5％，甲醇约98.9％。 H₂）。在甲烷与磁铁矿之间的反应过程中，铁氧化物的还原首先发生在铁氧化物与惰性成分（例如Al / Mg氧化物）之间的边界处，然后扩散到相邻区域并形成许多较小的Fe岛。铁岛周围的通道为甲烷的扩散提供了途径，改善了氧载体的进一步还原。