Effect of the support on the fischer–tropsch synthesis with Co/Nb2O5 catalysts

Abstract

Niobia-supported cobalt catalysts reduced at temperatures between 553 and 773 K have been compared with alumina-supported cobalt catalysts. The hydrogen adsorption capacity and the catalytic properties for the CO–H₂ reaction were independent of the temperature of reduction of the alumina-supported catalyst. In contrast, the amount of hydrogen chemisorbed and the activity for CO conversion decreased with increasing reduction temperature for the niobia-supported catalyst. The results are interpreted in terms of the strong metal–support interaction (SMSI) effect, established for Co/Nb₂O₅ after reduction at 673 and 773 K and not fully destroyed during the catalytic reaction. Higher temperatures of reduction of Co/Nb₂O₅ catalysts results in a better selectivity towards C₅⁺ compounds and a low selectivity towards C₁, in the CO–H₂ reaction performed at 533 K.