Chemical looping process is a novel energy conversion scheme, in which the in-situ carbon capture and high energy conversion efficiency could be realized without energy penalty. Ferrite (Fe₃O₄) is one of many good oxygen carrier candidates, due to its unique lattice structure containing a number of empty tetrahedral and octahedral interstitial sites. We calculated electronic properties of the original Fe₃O₄ primary cell and its lattice substituted by Ca or Ba, focusing on the correlation of their electronic structures and redox activities. Differences in their electronic densities and atomic charges in Mulliken Populations reveal more negative oxygen ions appearing in the substituted cells. Electronic structure analysis demonstrates that the substitution of Ba makes Fe₃O₄ more electric conductive and its electron is prone to be exited, that is in consistent to the experimental fact that BaFe₂O₄ performed better in chemical looping reactions compared to ferrites substituted by other alkali earth elements.

中文翻译：

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Ca和Ba取代的Fe3O4的电子性质与其在化学成环过程中的反应性之间的关系：第一性原理研究

化学循环过程是一种新颖的能量转化方案，其中原位碳捕获和高能量转化效率可以实现而没有能量损失。铁素体（Fe ₃ O ₄）由于其独特的晶格结构包含许多空的四面体和八面体间隙位置，因此是许多良好的氧载体候选物之一。我们计算了原始Fe ₃ O _4的电子性质原电池及其被Ca或Ba取代的晶格，着重于其电子结构与氧化还原活性的相关性。在Mulliken种群中，它们的电子密度和原子电荷的差异表明，替代细胞中出现更多的负氧离子。电子结构分析表明，Ba的取代使Fe ₃ O ₄更具导电性，并且其电子易于被排出，这与实验事实相吻合，即BaFe ₂ O ₄在化学环化反应中比被Fe取代的铁氧体表现更好。其他碱土元素。