Abstract: One zeolite capsule catalyst with a new core(Co／Al2O3)／shell(Hbeta membrane) structure was prepared and utilized for the middle isoparaffin direct synthesis via FischerTropsch synthesis (FTS) reaction. Characterization results exhibited that this beta zeolite capsule catalyst had a compact, integral beta shell. In FTS reaction on this beta zeolite capsule catalyst, hydrocarbons of C12+ were totally suppressed, accompanied by a sharp antiAndersonSchultzFlory (ASF) law product distribution. The selectivity of light isoparaffin was improved obviously, but with the increase of the olefin’s selectivity. Based on this core／shell Hbeta zeolite capsule catalyst, a novel palladium painted zeolite capsule catalyst with tripart core／shell／paint structure was prepared. Dependent on the palladium role of hydrogenation and hydrogen spillover, the olefins effused from the zeolite capsule catalyst were hydrogenated effectively, mostly converted to isoparaffin. The result proved that this tripart Hbeta zeolite capsule catalyst was effective, especially for the consecutively multistep reaction.

Key words: isoparaffin, zeolite, capsule catalyst, tripart structure, hydrogenation