Adsorption of water and n-hexane on pristine and oxidized carbon nanotube supports of cobalt-based Fischer–Tropsch catalysts

Abstract

Adsorption of model polar (water) and non-polar (n-hexane) compounds on the surface of oxidized and non-oxidized carbon nanotube (CNT) supports at different stages of Co/CNT catalyst preparation has been studied to reveal the influence of the surface functionalization of the CNT support on the catalyst selectivity in Fischer–Tropsch synthesis (FTS). Dynamic vapor sorption experiments showed that defunctionalization of the surface of the CNT support during catalyst annealing and reduction led to its hydrophobization and, as a result, no noticeable difference was observed between the adsorption properties of the oxidized and non-oxidized supports towards water and hydrocarbons. Therefore, oxidation of the CNT support does not significantly affect the adsorption properties of the supported catalyst and it is not a crucial factor for the catalyst selectivity in FTS.