In situ EXAFS study of the bimetallic interaction in a rhenium-promoted alumina-supported cobalt Fischer-Tropsch catalyst

Abstract

The local environments about the rhenium atoms in a Co–Re/γ-Al2O3 catalyst after different reduction periods have been studied by X-ray absorption spectroscopy (EXAFS). The bimetallic catalyst containing 4.6 wt% cobalt and 2 wt% rhenium has been compared with a corresponding monometallic sample with 2 wt% rhenium on the same support. The rhenium LIII EXAFS analysis shows that bimetallic particles are formed after reduction at 450 ○C with the average particle size being less than 15 A. More than 6 h reduction at 450 ○C is required for complete reduction of accessible rhenium.