Aerosol synthesis of porous SiO2-cobalt-catalyst with tailored pores and tunable metal particle size for Fischer-Tropsch synthesis (FTS)

Abstract

Cobalt nanoparticles supported on a well-defined porous structure are a promising catalyst for the Fischer-Tropsch synthesis (FTS). The catalytic efficiency of the porous catalyst depends on the properties of the support and on the properties of the active component. Methods such as wet-chemistry and flame synthesis are often limited by their variability in terms of support structure and size of the integrated active metal components. In this work, well-organised porous structures were produced using spray-drying of colloidal silica suspensions containing dissolved cobalt nitrate. This technique allows to synthesize catalyst particles with tunable specific surface area, pore size, cobalt particle size, and cobalt loading. The dried silica particles show interconnected pores, which makes it especially suitable for use as a catalyst support. Moreover, it is shown that the pore sizes and active metal particle sizes can be varied independently. In addition, the mass of cobalt oxide per silica support surface was identified as a controlling parameter for the metal oxide nanoparticle size for a given calcination temperature.