The formation and influence of carbon on cobalt-based Fischer-Tropsch synthesis catalysts : an integrated review

Cobalt-based Fischer-Tropsch synthesis (FTS) catalysts are the systems of choice for use in gas-to-liquid (GTL) processes. As with most catalysts, cobalt systems gradually lose their activity with increasing time on stream. There are various mechanisms that have been proposed for the deactivation of cobalt-based catalysts during realistic FTS conditions. These include poisoning, sintering, oxidation, metal support compound formation, restructuring of the active phase, and carbon deposition. Most of the recent research activities on cobalt catalyst deactivation during the FTS have focused on loss of catalyst activity due to oxidation of the metal and support compound formation. Relatively few recent studies have been conducted on the topic of carbon deposition on cobalt-based FTS catalysts. The purpose of this review is to integrate the existing open and patent literature with some of our own work on the topic of carbon deposition to provide a clearer understanding on the role of carbon as a deactivation mechanism