CH₄-CO₂ chemical looping is proposed for separate H₂ and CO production using nanostructured Fe-Ni looping materials. The product streams are obtained by first feeding CH₄, which decomposes to H₂ and carbon. The latter acts as reductant for the subsequent CO₂ feed, which together with Fe re-oxidation yields CO. After 25 CH₄-CO₂ cycles, 10Fe5Ni@Zr has a higher H₂ space–time yield than 10Fe0Ni@Zr ($20\text{mmol}{\mathrm{s}}^{-1}{\mathrm{kg}}_{\mathrm{Fe}+\mathrm{Ni}}^{-1}$ vs. $15\text{mmol}{\mathrm{s}}^{-1}{\mathrm{kg}}_{\mathrm{Fe}+\mathrm{Ni}}^{-1}$), a 2.6 times higher CO yield ($57\text{mmol}{\mathrm{s}}^{-1}{\mathrm{kg}}_{\mathrm{Fe}+\mathrm{Ni}}^{-1}$) and lower deactivation. This improvement has two reasons: (i) CH₄ activation over Ni leading to cracking, (ii) product hydrogen causing deeper FeO reduction. Deactivation follows from accumulated carbon, non-reactive for CO₂. On Ni and Fe sites, carbon can be removed by lattice oxygen or CO₂, yielding more CO compared to the theoretical value for Fe oxidation. However, carbon that migrates away from the metals requires oxygen for removal, which restores the activity of the Ni-containing samples.

中文翻译：

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将 H2 和 CO 从 Fe-Ni 的 CH4-CO2 循环中分离出来

建议使用纳米结构的 Fe-Ni 循环材料单独生产 H ₂和 CO 的CH ₄ -CO _{2化学循环。}通过首先进料CH ₄获得产物流，CH 4分解为H ₂和碳。后者作为后续CO ₂进料的还原剂，与Fe再氧化一起生成CO。经过25次CH ₄ -CO ₂循环后，10Fe5Ni@Zr的H ₂时空产率高于10Fe0Ni@Zr（$20\text{毫摩尔}{\mathrm{s}}^{-1}{\mathrm{公斤}}_{铁+你}^{-1}$对比$15\text{毫摩尔}{\mathrm{s}}^{-1}{\mathrm{公斤}}_{铁+你}^{-1}$），二氧化碳产量高出 2.6 倍（$57\text{毫摩尔}{\mathrm{s}}^{-1}{\mathrm{公斤}}_{铁+你}^{-1}$) 和较低的停用。这种改进有两个原因：（i）在 Ni 上的 CH ₄活化导致开裂，（ii）产物氢导致更深的 FeO 还原。失活源于积累的碳，对 CO ₂不反应。在 Ni 和 Fe 位点上，碳可以通过晶格氧或 CO ₂去除，与 Fe 氧化的理论值相比，产生更多的 CO。然而，从金属中迁移出来的碳需要氧气来去除，这会恢复含镍样品的活性。