Differences in characteristics and catalytic properties of Co catalysts supported on micron- and nano-sized zirconia

Abstract

Nanocrystalline zirconia was prepared by decomposition of zirconium tetra n-propoxide in 1,4-butanediol and was employed as a support for cobalt catalysts. The activity and the selectivity of the catalysts in CO hydrogenation were compared with cobalt supported on commercial available micron- and nano-sized zirconia. The catalytic activities were found to be in the order: Co/ZrO 2-nano-glycol ≫ Co/ZrO 2-nano-com > Co/ZrO 2-micron-com. Compared to the micron-sized zirconia supported one, the use of commercial nano-sized zirconia resulted in higher CO hydrogenation activity but lower selectivity for longer chain hydrocarbons (C 4–C 6), whereas the use of glycothermal-derived nanocrystalline zirconia exhibited both higher activity and selectivity for C 4–C 6. The better performance of the latter catalyst can be ascribed to not only the effect of the crystallite size but also the presence of pure tetragonal phase of zirconia.