Abstract Potassium promoted iron–zinc catalysts prepared by co-precipitation method (C–Fe–Zn/K), solvothermal method (S–Fe–Zn/K) and hydrothermal method (H–Fe–Zn/K) could selectively convert CO 2 to light olefins, respectively. The physicochemical properties of the obtained catalysts were determined by SEM, N 2 physisorption, XRD, H 2 -TPR, CO 2 -TPD and XPS measurements. The results demonstrated that preparation methods had great influences on the morphology, phase structures, reduction and adsorption behavior, and hence the catalytic performance of the catalysts. The samples prepared by hydrothermal and co-precipitation method generated small uniform particles and led to lower specific surface area. In contrast, microspheres with larger specific surface area were formed by self-assembly of nanosheets using solvothermal method. ZnFe 2 O 4 was the only detectable phase in the fresh C–2Fe–1Zn/K, S–3Fe–1Zn/K and S–2Fe–1Zn/K samples. ZnFe 2 O 4 and ZnO co-existed with increasing Zn content in S–1Fe–1Zn/K sample, while ZnO and Fe 2 O 3 could be observed over H–2Fe–1Zn/K sample. All the used samples contained Fe 3 O 4 , ZnO and Fe 5 C 2 . The peak intensity of ZnO was strong in the AR-H–2Fe–1Zn/K sample while it was the lowest in the AR-C–2Fe–1Zn/K sample after reaction. The formation of ZnFe 2 O 4 increased the interaction between iron and zinc for C–2Fe–1Zn/K and S–Fe–Zn/K samples, causing easier reduction of Fe 2 O 3 to Fe 3 O 4 . The surface basicity of the sample prepared by co-precipitation method was much more than that of the other two methods. During CO 2 hydrogenation, all the catalysts showed good activity and olefin selectivity. The CO selectivity was increased with increasing Zn content over S–Fe–Zn/K samples. H–2Fe–1Zn/K catalyst preferred to the production of C 5 + hydrocarbons. CO 2 conversion of 54.76% and C 2 = –C 4 = contents of 57.38% were obtained on C–2Fe–1Zn/K sample, respectively.

中文翻译：

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制备方法对CO 2 加氢制轻烯烃Fe-Zn/K催化剂结构和催化性能的影响

摘要 通过共沉淀法 (C-Fe-Zn/K)、溶剂热法 (S-Fe-Zn/K) 和水热法 (H-Fe-Zn/K) 制备的钾促进铁锌催化剂可以选择性地转化 CO 2 分别为轻质烯烃。所得催化剂的理化性质通过SEM、N 2 物理吸附、XRD、H 2 -TPR、CO 2 -TPD和XPS测量确定。结果表明，制备方法对催化剂的形貌、相结构、还原和吸附行为以及催化性能有很大影响。通过水热和共沉淀法制备的样品产生小的均匀颗粒并导致较低的比表面积。相比之下，具有较大比表面积的微球是通过使用溶剂热法自组装纳米片形成的。ZnFe 2 O 4 是新鲜 C-2Fe-1Zn/K、S-3Fe-1Zn/K 和 S-2Fe-1Zn/K 样品中唯一可检测的相。随着 S-1Fe-1Zn/K 样品中 Zn 含量的增加，ZnFe 2 O 4 和 ZnO 共存，而在 H-2Fe-1Zn/K 样品中可以观察到 ZnO 和 Fe 2 O 3。所有使用的样品都含有Fe 3 O 4 、ZnO和Fe 5 C 2 。反应后，在 AR-H-2Fe-1Zn/K 样品中 ZnO 的峰值强度很强，而在 AR-C-2Fe-1Zn/K 样品中最低。对于 C-2Fe-1Zn/K 和 S-Fe-Zn/K 样品，ZnFe 2 O 4 的形成增加了铁和锌之间的相互作用，导致 Fe 2 O 3 更容易还原为 Fe 3 O 4 。共沉淀法制备的样品表面碱度远高于其他两种方法。在CO 2 加氢过程中，所有催化剂均表现出良好的活性和烯烃选择性。与 S-Fe-Zn/K 样品相比，CO 选择性随着 Zn 含量的增加而增加。H-2Fe-1Zn/K 催化剂优选用于生产 C 5 + 碳氢化合物。在 C-2Fe-1Zn/K 样品上分别获得了 54.76% 的 CO 2 转化率和 57.38% 的 C 2 = –C 4 = 含量。