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

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.

Graphical abstractThe cobalt catalyst supported on the nanostructured alumina increased the CO conversion by 20–30%, compared to commercial alumina. Among the nanostructured alumina, the nanofiber supported catalyst has improved stability through the large, stable and interconnected bird nest-like pore structures with large cobalt particle size and showed the best catalytic performance.Figure optionsDownload full-size imageDownload high-quality image (111 K)Download as PowerPoint slideHighlights► The morphologies of nanostructured Al2O3 effect on cobalt catalysts for FTS were reported. ► Nano-Al2O3 supports undergo reconstruction during the catalyst preparation. ► Nano-Al2O3 improved CO conversion by 20–30% compared to commercial Al2O3. ► Al2O3 nanofibers have improved catalyst stability through bird nest-like pores.