화학공학소재연구정보센터
Fuel, Vol.239, 547-558, 2019
Spatially confined cobalt nanoparticles on zirconium phosphate-modified KIT-6 for an enhanced stability of CO hydrogenation to hydrocarbons
The positive effects of zirconium phosphate (ZrP)-modified highly ordered mesoporous KIT-6 support for an insignificant aggregation of the supported cobalt nanoparticles (CoZrP/KIT-6) were investigated by CO hydro-genation to hydrocarbons such as Fischer-Tropsch synthesis (FTS) reaction. The roles of the newly formed ZrP phases on the KIT-6 were mainly explained in terms of metal dispersion with its modulated metal-support interaction as well as suppressed coke formations. The mesoporous KIT-6 surfaces modified with partial ZrP nanoparticles at an optimum molar ratio of P/Zr = 0.2 significantly enhanced the catalytic stability with a higher C5+, selectivity through the preferential formations of the spatial confined cobalt nanoparticles in the matrices of the well-dispersed ZrP nanoparticles on the mesoporous KIT-6 surfaces. The superior catalytic activity and stability were mainly attributed to the inhibited aggregations of the intimately interacted cobalt nanoparticles in the ZrP matrices due to a preferential presence of the highly dispersed and thermally stable hydrophobic ZrP phases. This was also responsible for the less formation of coke precursors such as cobalt carbides or heavy wax hydrocarbons. However, the different types of coke precursors on the used CoZrP/KIT-6 largely altered the catalytic stability and activity with the simultaneous aggregations of cobalt nanoparticles by forming the abundant heavy hydrocarbons on the unstable CoZrP(2)/KIT-6 prepared at a higher P/Zr ratio of 2 as well as by forming the inactive coke-derived cobalt carbides on the unmodified CoZrP(0)/KIT-6 and Co/KIT-6 under the reductive FTS reaction condition.