Fischer–Tropsch synthesis: Studies effect of reduction variables on the performance of Fe–Ni–Co catalyst

•Phase transform was dependent with temperature.•The formation of iron carbides, Co and Ni metallic provided the FTS active sites.•Increasing reduction temperature cusses the higher activity.•Initial activity depends on the agent used and is in the order of H2 > CO > H2: CO = 1.

The effect of reduction temperature (200–450 °C) and various atmospheres on the performance of Fe–Ni–Co catalyst in a fixed bed reactor have been investigated. Catalysts were prepared by co-precipitation procedure and used for CO hydrogenation in Fischer–Tropsch synthesis (FTS). The catalyst which was reduced at 300 °C under H2 atmosphere showed the best catalytic performance for higher CO conversion and low CH4 selectivity. The initial activity depends on the atmosphere used and is in the order of H2 > CO > H2: CO = 1. XRD, SEM/EDS, and BET characterization of precursor, calcinated and reduced catalysts showed that while by increasing reduction temperature; the pore volume increases and their pore size decreases. It was observed that the phase composition of catalysts reduced with H2 is strongly dependent on the pretreatment conditions.