铁基费托催化剂预处理过程的原位表征技术研究进展

Research progress on the in-situ characterizations of iron-based FTS catalysts pretreatment process

铁基费托合成(FTS)催化剂通常以氧化物前驱体α-Fe_(2)O_(3)的形式存在,在不同预处理条件下转变为铁碳化合物FexCy后具有不同的催化活性,因此,研究催化剂预处理过程对费托合成反应具有重要意义。然而该过程中物相体系高度动态复杂,通过常规表征手段无法捕捉到铁基催化剂准确的变化信息。为了深入探究前驱体α-Fe_(2)O_(3)体系在不同预处理过程中的真实变化,需要借助多种原位表征技术获取催化剂物相、形貌及其表面结构和性质的动态变化数据,从而可实现催化剂预处理过程和后续FTS催化性能的有效关联。本工作系统综述了X射线衍射、透射电子显微镜、X射线光电子能谱、红外光谱和拉曼光谱等原位表征技术在铁基FTS催化剂预处理过程中的实验方法以及数据处理方法,以明晰催化剂前驱体复杂的结构性质变化过程,进而促进更高效铁基FTS催化剂的设计和开发。

Fe-based Fischer-Tropsch synthesis(FTS)catalysts usually exist as the oxide precursorα-Fe_(2)O_(3),which have different catalytic activities after being transformed to FexCy under different pretreatment conditions,so it is critical to study the pretreatment process ofα-Fe_(2)O_(3)for whole FTS reaction.However,the phases of Fe-based catalysts in such a process are highly dynamic and complex,and conventional characterizations cannot capture the accurate real-time information in the pretreatment reaction.Therefore,it is necessary and desired to apply various in-situ characterizations in this process,because they can obtain the dynamic changes of phase,morphology,surface structure and properties of the catalyst.And then a relationship between the pretreatment process and the subsequent catalytic performance of FTS will be effectively and reasonably established.This review presents a systematic summary of the experimental and data processing methods in in-situ characterizations of X-ray diffraction,transmission electron microscopy,X-ray photoelectron spectroscopy,infrared spectroscopy and Raman spectroscopy during the pretreatment of Fe-based FTS catalysts.These characterizations can clarify the complex structure and surface property changes of catalyst precursors and thus will facilitate the design and development of more efficient Fe-based FTS catalysts.