One-step synthesis of H–β zeolite-enwrapped Co/Al2O3 Fischer–Tropsch catalyst with high spatial selectivity
2009; Elsevier BV; Volume: 265; Issue: 1 Linguagem: Inglês
10.1016/j.jcat.2009.04.009
ISSN1090-2694
AutoresXingang Li, Jingjiang He, Ming Meng, Yoshiharu Yoneyama, Noritatsu Tsubaki,
Tópico(s)Catalysis and Hydrodesulfurization Studies
ResumoA tailor-made encapsulated catalyst with a H–β zeolite shell has been directly synthesized over Co/Al2O3 pellets to form a core–shell structure without pinholes and cracks by a hydrothermal synthesis method. Pretreatment of the Co/Al2O3 pellets with reflux of hot TEAOH solution can clean and corrode the pellet surface due to its strong basicity, and can enlarge the mean pore size of the pellets. Impregnation of the Co/Al2O3 pellets in EtOH is important to avoid the corrosion of the internal pores, to prevent the introduction of Co species into the zeolite coating, and to realize a pure and uniformed β-zeolite coating. For the catalytic reaction of direct isoparaffin synthesis from syngas, the molar ratio of Cisoparaffin/Cnormal-paraffin of the products obtained from the encapsulated catalyst increased about 64% than that of the products obtained from physical-mixed components. This concept of encapsulated catalyst can be useful to carry out various consecutive or multiple-step catalytic processes, where multiple reactions occur on different active centers.
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