Effect of CO2 in the feed stream on the deactivation of Co/γ-Al2O3 Fischer–Tropsch catalyst

The influence of CO2 on the deactivation of Co/γ-Al2O3 Fischer–Tropsch (FT) catalyst in CO hydrogenation has been investigated. The presence of CO2 in the feed stream reveals a negative effect on catalyst stability and in the formation of heavy hydrocarbons. The CO2 acts as a mild oxidizing agent on cobalt metal during Fischer–Tropsch synthesis. During FT synthesis on Co/γ-Al2O3 of 70 h, the CO conversion and C5+ selectivity in the presence of CO2 decreased more significantly than in the absence of CO2. CO2 is found to be responsible for the partial oxidation of surface cobalt metal at FT synthesis environment with the co-existence of generated water.