Preparation and Characterization of Silica-Modified Aromatic Polymer-Based Catalysts for Fischer-Tropsch Synthesis

Abstract

The polymer can be effectively used as the supports for catalyst preparation. The main disadvantage of the polymer support is the absence of the acid-base sites on its surface. The modification of the polymeric support is one of the ways to solve this problem. In the current work, the modification of the surface of the hypercrosslinked polystyrene was carried out to apply the silicon oxide and provide the acid sites on the polymer. The effect of the silica deposition method and silica precursor was studied by the physics chemical analysis. The precipitation of the silica in subcritical water was found to provide the higher specific surface area of the resulting support (over 700 m²/g) in comparison with the wet-impregnation method. The use of ethoxysilanes, particularly 3-aminopropyltriethoxysilane, as a silica precursor was found to lead to the full deposition of Si. The synthesized modified support was used for the preparation of the catalyst for Fischer-Tropsch synthesis. Lewis acid sites on the catalyst support facilitate the CO adsorption and enhance the production of hydrocarbons via Fischer-Tropsch synthesis. The use of the catalysts on the silica-modified support showed a three-fold increase in CO conversion with an increase in the selectivity towards the oxygenates.