Design of a zeolite capsule catalyst by controlling the support size for the direct synthesis of isoparaffin

Three kinds of H-ZSM-5 zeolite capsule catalysts were prepared on Co/SiO2 catalyst pellets of different sizes. Characterization of the catalysts indicated that a defect-free H-ZSM-5 membrane had been constructed successfully on the Co/SiO2 surface. The smaller Co/SiO2 pellets were favorable for zeolite capsule growth under the same synthesis conditions. Zeolite capsule catalysts, especially the catalysts with smaller pellet sizes, had a higher isoparaffin selectivity compared with conventional FTS Co/SiO2 catalyst and mixed catalyst of Co/SiO2 with H-ZSM-5 zeolite.