In this work, Fe–Zn catalysts were prepared, characterized, and examined for the synthesis of linear high carbon α-olefins (LAOs; C ≥ 4) directly from CO₂ hydrogenation. The relationship of performance and structure has been established to unravel the role of ZnO in bimetallic Fe₅C₂–ZnO catalysts. A Fe2Zn1 catalyst showed high selectivity to C₂–C₇ olefins (a selectivity of 57.8% in gas phase) after 200 h of time-on-stream and total C₄₊ olefins selectivity in liquid products of 81.9% with 85.9% LAOs in C₄₊ alkenes at a CO₂ conversion of 35.0%. The dominant mechanism of deactivation was ascribed to phase transformation from FeC_x to FeO_x in comparison with Fe₂O₃ and Fe5Zn1. Zn and Na were proved to migrate onto the surface during the activation process. The interaction between Zn and Na could suppress the oxidation of FeC_x by H₂O and CO₂. This study revealed the deactivation mechanism and stabilization effects of Zn on the active phase of FeC_x during CO₂ hydrogenation.

中文翻译：

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揭示锌在高选择性碳氢化为高碳α-烯烃的双金属Fe ₅ C ₂ -ZnO催化剂上的作用

在这项工作中，制备，表征和检验了直接由CO ₂加氢合成线性高碳α-烯烃（LAOs; C≥4）的Fe-Zn催化剂。已经建立了性能和结构之间的关系，以阐明ZnO在双金属Fe ₅ C ₂ -ZnO催化剂中的作用。在运行200小时后，Fe2Zn1催化剂显示出对C ₂ -C ₇烯烃的高选择性（气相中的选择性为57.8％），液体产品中的总C ₄₊烯烃选择性为81.9％，其中LAO为85.9％。 C ₄₊烯烃的CO ₂转化率为35.0％。失活的主要机理归因于FeC的相变与Fe ₂ O ₃和Fe5Zn1相比， _x为FeO _x。锌和钠被证明在活化过程中迁移到表面上。Zn和Na的相互作用可以抑制H ₂ O和CO ₂对FeC _x的氧化。这项研究揭示了Zn在CO ₂加氢过程中对FeC _x活性相的失活机理和稳定作用。