Fischer-Tropsch is an important technology for the efficient use of energy such as coal, natural gas and biomass?which can convert syngas into high value-added chemicals. Co-based catalysts are promising Fischer- Tropsch synthesis industrial catalysts due to their excellent carbon growth ability and low water vapor shift reaction. In order to improve the performance of Co-based catalysts, it is necessary to conduct a comprehensive and in-depth study and exploration of its Fischer-Tropsch synthesis mechanism. Modified alumina carriers were obtained by pre- coating cobalt aluminate on the surface of common alumina. Next, supported cobalt catalysts were obtained by incipient wetness impregnation, and their FTS performances were evaluated in a fixed-bed reactor. In situ XRD results suggested that HCP Co was obtained after reducing the aluminate-modified alumina-supported cobalt catalysts, as opposed to FCC Co, which was supported on common alumina. H2-TPR results demonstrated that the modified catalysts possessed lower reduction temperatures. CO-TPD and in situ CO-FTIR characterizations indicated that bridged rather than linear CO adsorption occurred on the modified catalysts.
The evaluation results indicated that the aluminate-modified catalysts possessed higher CO conversion rates, higher C5 selectivity, higher cobalt specific activity, higher C5+ space-time yields (STYs), and lower methane selectivity than conventional catalysts in the FTS process.