Harnessing solar energy for CO conversion to fuels presents a sustainable alternative to fossil fuels. However, finding an economical, stable, non-toxic nanomaterial catalyst poses a significant challenge. Understanding the catalyst’s active state is vital for optimal performance due to potential structural changes during reactions. Herein, we employ various characterizations to detail δ-FeOOH’s structural evolution during hydrogen activation, identifying its active phase while catalyzing the heterogeneous reduction of CO by H. Using environmental transmission electron microscopy, δ-FeOOH is first dehydrated to α-FeO, then reduced to FeO, and finally to α-Fe. Other characterizations revealed that the active state of the catalyst (Fe-350-H) is a mixture of FeO and α-Fe. A detailed investigation into the photocatalytic CO reduction using batch, flow, and LED reactors unveiled that the Fe-350-H catalyst exhibits superior activity and selectivity in activating the reverse water gas shift reaction compared with similar iron-based catalysts.

中文翻译：

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原位探究高选择性铁基CO2还原光催化剂的结构变化和活性态演化


利用太阳能将二氧化碳转化为燃料是化石燃料的可持续替代品。然而，寻找经济、稳定、无毒的纳米材料催化剂提出了重大挑战。由于反应过程中潜在的结构变化，了解催化剂的活性状态对于获得最佳性能至关重要。在此，我们采用各种表征来详细描述δ-FeOOH在氢活化过程中的结构演变，识别其活性相，同时催化H对CO的非均相还原。使用环境透射电子显微镜，δ-FeOOH首先脱水为α-FeO​​，然后还原到FeO，最后到α-Fe。其他表征表明，催化剂（Fe-350-H）的活性态是FeO和α-Fe的混合物。使用间歇式、流动式和 LED 反应器对光催化 CO 还原进行的详细研究表明，与类似的铁基催化剂相比，Fe-350-H 催化剂在激活逆水煤气变换反应方面表现出优异的活性和选择性。