Performance and characterization of Ru/Al2O3 and Ru/SiO2 catalysts modified with Mn for Fischer–Tropsch synthesis

Mn effect and characterization on γ-Al2O3-, α-Al2O3- and SiO2-supported Ru catalysts were investigated for Fischer–Tropsch synthesis under pressurized conditions. In the slurry phase Fischer–Tropsch reaction, γ-Al2O3 catalysts showed higher performance on CO conversion and C5+ selectivity than α-Al2O3 and SiO2 catalysts. Moreover, Ru/Mn/γ-Al2O3 exhibited high resistance to catalyst deactivation and other catalysts were deactivated during the reaction. From characterization results on XRD, TPR, TEM, XPS and pore distribution, Ru particles were clearly observed over the catalysts, and γ-Al2O3 catalysts showed a moderate pore and particle size such as 8 nm, where α-Al2O3 and SiO2 showed highly dispersed ruthenium particles. The addition of Mn to γ-Al2O3 enhanced the removal of chloride from RuCl3, which can lead to the formation of metallic Ru with moderate particle size, which would be an active site for Fischer–Tropsch reaction. Concomitantly, manganese chloride is formed. These schemes can be assigned to the stable nature of Ru/Mn/γ-Al2O3 catalyst.

The addition of Mn to γ-Al2O3-supported Ru catalyst enhanced the catalytic activity and stability for Fischer–Tropsch synthesis. According to the catalyst characterization results, moderate Ru particle size was observed and active site of Ru atoms was increased by the formation of MnCl2. Figure optionsDownload as PowerPoint slide