Effect of Ni-Co morphology on kinetics for Fischer-Tropsch reaction in a fixed-bed reactor

In order to investigate the effect of catalyst morphology on the kinetics modeling and mechanism of Fischer-Tropsch Synthesis (FTS), experiments were conducted on single-phase face-centered cubic NiCo2O4 catalysts with different morphologies in a fixed-bed reactor under identical operating conditions. A simple template-free hydrothermal method is presented for the preparation of NiCo2O4 nanowires (NiCo-NWs). In addition, hierarchical NiCo2O4 hollow microspheres (NiCo-HMS) and hierarchical NiCo2O4 microspheres (NiCo-MS) are prepared by hydrothermal method. Characterization of catalysts was carried out using BET, SEM, EDX, XRD and TEM techniques. The findings revealed that CO dissociation is closely dependent on the morphology of catalysts, and proceeds via H-assisted route over NiCo-NWs, but direct CO dissociation route occurs over NiCo-HMS and NiCo-MS. The kinetics models of all three catalysts were able to correctly predict the experimental rate data. The obtained kinetics parameters for FTS catalytic process over NiCo-NWs, NiCo-HMS and NiCo-MS are in good agreement with the literature reports. (C) 2019 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.