Heterogeneous iron catalysts are active in the hydrogenation of carbon oxides and are widely investigated for the production of long‐chained hydrocarbons according to the Fischer‐Tropsch synthesis. Moreover, high selectivity of light hydrocarbons, such as CH₄, also occurs strongly depending on reaction conditions and catalyst formulations. As a consequence, Fe catalysts reveal promising methanation activity as referred to the traditional Ni catalysts. Additionally, Fe catalysts also benefit from their low price and toxicological harmlessness. However, the dynamic behavior of iron upon CO₂ hydrogenation is not yet unraveled unambiguously including phase transformations, structural changes and participation of carbon species formed. The present review highlights these complex processes of Fe catalysts with special focus on the methanation of CO₂. Additionally, different analytical tools useful for ex situ and in situ studies are critically evaluated.

中文翻译：

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CO基加氢制CH4期间铁基催化剂的活性和结构变化–简述

非均相铁催化剂在碳氧化物的加氢中具有活性，根据费-托合成法，非均相铁催化剂可用于生产长链烃。此外，取决于反应条件和催化剂配方，强烈出现轻质烃如CH _4的高选择性。结果，与传统的Ni催化剂相比，Fe催化剂显示出有希望的甲烷化活性。此外，铁催化剂还因其价格低廉和毒理学无害而受益。但是，铁在CO _2上的动力学行为尚未明确阐明氢化作用，包括相变，结构变化和形成的碳物种的参与。本综述着重介绍了Fe催化剂的这些复杂过程，特别侧重于CO ₂的甲烷化。此外，严格评估了可用于异地和原位研究的不同分析工具。