Synthesis, characterization, and Fischer-Tropsch performance of cobalt/zinc aluminate nanocomposites via a facile and corrosion-free coprecipitation route

摘要

Literature about ZnAl2O4-supported cobalt Fischer-Tropsch synthesis (FTS) catalytic materials is sparse. A series of cobalt-containing nanocomposites, supported by nanosized ZnAl2O4 spinel (i.e., a complex oxide of about 6.4 nm) or alumina (i.e., a simple oxide of about 6.2 nm), were prepared via urea-gelation, coprecipitation, or impregnation methods followed by stepwise reduction. These materials were examined by XRD, TGA, nitrogen sorption, FESEM, and EDS. Effects of corrosion and pore size distributions on materials preparation were also investigated. The "coprecipitation/stepwise reduction'' route is facile and suitable to prepare nanosized ZnAl2O4-supported Co-0 nanocomposites. At similar CO conversions, the coprecipitated Co/ZnAl2O4 exhibits significantly lower C-1 hydrocarbon distribution, slightly lower C5+ hydrocarbon distribution, significantly higher C-2-C-4 hydrocarbon distribution, and significantly higher olefin/paraffin ratio of C-2-C-4 than Co/c-Al2O3.