Formation of metal-support compounds in cobalt-based Fischer-Tropsch synthesis: A review
Moritz Wolf, Nico Fischer, Michael Claeys
Abstract
Herein, the feasibility of water-induced deactivation of cobalt-based Fischer-Tropsch catalysts by oxidation is summarized and discussed with the help of thermodynamic predictions. Furthermore, identified mechanisms for hydrothermal sintering and recent findings on water-induced oxidation of metallic cobalt to CoO are discussed. However, the main emphasis of the review concerns the formation of metal-support compounds and the applicability of various in situ and ex situ characterization techniques on their identification. The current literature only provides limited information on the formation and morphology of metal-support compounds in cobalt-based Fischer-Tropsch synthesis due to the challenging (direct) characterization of these phases in spent catalysts. However, X-ray absorption spectroscopy and other advanced techniques have recently provided significant insights into the formation of metal-support compounds in a (simulated) high-conversion Fischer-Tropsch environment, while high-resolution microscopy was successfully applied to elucidate corresponding catalyst morphologies.