Cobalt aluminate-modified alumina as a carrier for cobalt in Fischer–Tropsch synthesis

Abstract

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.