OICC Press International Journal of Industrial Chemistry 2228-5547 16 3 2025 12 09 Study of CO Hydrogenation over Cobalt-based Catalysts: Synergistic Effect 10.57647/j.ijic.2025.1603.13 EN Arefeh Sadeghi Nikou Department of Chemistry, NT.C., Islamic Azad University, Tehran, Iran Shahram Moradi Dehaghi Department of Chemistry, NT.C., Islamic Azad University, Tehran, Iran Yahya Zamani Department of Chemistry, NT.C., Islamic Azad University, Tehran, Iran; Gas Research Division, Research Institute of Petroleum Industry, Tehran, Iran Jafar Sadeghzadeh Ahari Department of Chemistry, NT.C., Islamic Azad University, Tehran, Iran; Gas Research Division, Research Institute of Petroleum Industry, Tehran, Iran Journal Article 2025 12 09 A series of cobalt-based catalysts were prepared using γ-Al2O3 as a support and cerium/zirconium mixed oxides as promoters, with varying Ce/Zr molar ratios. The 15Co/γ-Al2O3, 15Co/3Zr/γAl2O3, 15Co/3Ce/γ-Al2O3 and 15Co/1.5Zr/1.5Ce/γ-Al2O3 were synthesized using the wet impregnation method. BET, TGA, FE-SEM, XRD, H2-TPR, and ICP techniques were used to determine the characteristics of the prepared catalysts. The findings showed that the catalyst (15Co/1.5Zr/1.5Ce/γ-Al2O3) with double promotion exceeded the performance of other catalysts, indicating notable synergistic effects. These effects are expected to play a crucial role in reducing side reactions that affect selectivity towards higher hydrocarbons. The 15Co/1.5Zr/1.5Ce/γAl2O3 catalyst demonstrated enhanced stability and reduced degradation during prolonged operation, resulting in higher CO conversion and effective suppression of excessive carbon chain growth. All prepared catalysts were tested in a fixed-bed reactor under a pressure of 27 bar, a temperature of 220 °C, and an H2/CO ratio of 2. The results showed that the doubly-promoted catalyst achieved superior performance, with CO conversion, C5+ selectivity, and yield reaching 50.4 ± 1.5%, 82.3 ± 0.9%, and 41.5 ± 0.8%, respectively, compared to the other catalysts. In conclusion, these findings confirm the substantial influence of Zr and Ce promoters on the performance of Co-based catalysts during the Fischer-Tropsch synthesis reaction.