Fischer-tropsch synthesis: Characterization and reaction testing of cobalt carbide

Hydrogenation of carbon monoxide was investigated for cobalt carbide synthesized from Co₃O₄ by CO carburization in a fixed-bed reactor. The cobalt carbide synthesized was characterized by BET surface area, X-ray diffraction, scanning electron microscopy, X-ray absorption near edge spectroscopy, and extended X-ray absorption fine structure spectroscopy. The catalysts were tested in the slurry phase using a continuously stirred tank reactor at P = 2.0 MPa, H₂/CO = 2:1 in the temperature range of 493-523 K, and with space velocities varying from 1 to 3 Nl h^-1 g_cat^-1. The results strongly suggest that a fraction of cobalt converts to a form with greater metallic character under the conditions employed. This was more pronounced on a Fischer-Tropsch synthesis run conducted at a higher temperature (523 versus 493 K).