Cobalt fischer-tropsch catalyst regeneration: The crucial role of the kirkendall effect for cobalt redispersion

Abstract

Redispersion of cobalt is a key process during Fischer-Tropsch catalyst regeneration. Using model catalysts we show that redispersion is a two step process. Oxidation of supported metallic cobalt nanoparticles produces hollow oxide particles by the Kirkendall effect; reduction leads to break-up of these hollow oxide shells, forming multiple metallic particles. This mechanism is to a large extent independent of the support. © 2011 Springer Science+Business Media, LLC.