Design of Co@Zeolite/Sic Capsule Catalyst for Direct Synthesis of Middle Olefin from Syngas

Fischer-Tropsch (FT) synthesis as a strongly exothermic reaction has diffusely manufactured clean fuels, whereas its product distribution is difficultly controlled. Here, we design ZSM-5 encapsulated cobalt particles on thermal conductivity of SiC matrix. The Co@NaZSM-5/SiC catalyst with hierarchical structure is ingeniously assembled through solvent-free synthesis route. The capsule catalysts, which Co is encapsulated in the NaZSM-5 zeolite via an in-situ crystallization method, exhibit abundant acid sites. The joint functions of zeolite acid, SiC thermal conductivity and macropores, improve olefin selectivity by 32.3%, where the middle olefins (O 5-11 ) selectivity approaches to 50%. Moreover, H ion-exchange catalyst (Co@HZSM-5/SiC) with strong acid sites boosts the olefin isomerization reaction, giving a high isoparaffin selectivity for 27.3%. Co 2 C phase is readily formed during the FT reaction, which is an activate center for olefin synthesis. The functional catalyst with the acidic site, thermal conductivity, and hierarchical structure is promising prospects for tuning production distribution in FT reaction.