Elucidating deactivation of titania-supported cobalt Fischer-Tropsch catalysts under simulated high conversion conditions
Luke M. van Koppen (Eindhoven University of Technology, TU Delft - RST/Fundamental Aspects of Materials and Energy)
A. I. Dugulan (TU Delft - RST/Fundamental Aspects of Materials and Energy, TU Delft - RID/TS/Instrumenten groep)
G. Bezemer (Shell Global Solutions International B.V.)
E. J.M. Hensen (Eindhoven University of Technology)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
The study of titania-supported cobalt nanoparticles is relevant for industrial Fischer-Tropsch synthesis (FTS). Herein, we report about various deactivation pathways of cobalt supported on P25 titania (cobalt loading 2–8 wt%) under simulated high conversion conditions using in situ Mössbauer spectroscopy. A fraction of metallic cobalt was oxidized under humid FTS conditions. The absolute amount of oxidized cobalt was ∼ 1.2 wt% independent of the cobalt loading, indicating that specific cobalt-titanol interactions are involved in the oxidation process. The formation of cobalt-titanate-like compounds was only observed under very high water-to-hydrogen ratios in the absence of carbon monoxide. Steam considerably enhances cobalt sintering under FTS conditions. As such, deactivation under humid FTS conditions is not only caused by cobalt oxidation but also by enhancing sintering of the active phase.
help_outline