Fischer–Tropsch synthesis over cobalt catalysts supported on nanostructured alumina with various morphologies

Abstract

Nanostructured aluminas with controllable morphologies were prepared and used as support of cobalt catalysts for Fischer–Tropsch synthesis. The supported cobalt catalysts were prepared by incipient wetness impregnation method and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), temperature programmed reduction (TPR), N2 adsorption–desorption, hydrogen chemisorption and oxygen titration. Catalytic activity of the cobalt catalysts for Fischer–Tropsch synthesis (FTS) was evaluated on a fixed bed reactor. It was found that the nanostructured alumina supports undergo reconstruction during the catalyst preparation resulting in catalysts having high dispersion after reduction. The cobalt catalyst supported on the nanostructured alumina increased the CO conversion by 20–30%, compared to commercial alumina. Among the nanostructured catalysts, the alumina nanorods supported catalyst, shows the best dispersion and highest CO initial conversion. Our work disclosed that the alumina nanofibers supported catalysts have larger, stable and interconnected bird nest-like pores. In addition, the structure exhibited higher stability and lower methane selectivity for FTS.