CO hydrogenation to C2-oxygenates over Rh-Mn-Li/SiO2 catalyst:: Effects of support pretreatment with nC1-C5 alcohols

The effects of support pretreatment with nC(1)-C-5 alcohols on the performance of Rh-Mn-Li/SiO2 catalyst in the synthesis of C-2-oxygenates from syngas have been investigated by CO hydrogenation reaction, transmission electron microscopy (TEM), pulse adsorption of CO and H-2, and Fourier Transform infrared (FT-IR) spectroscopy. The catalysts prepared from the pretreated silica supports exhibited higher space time yields of C-2-oxygenates (STYC2-oxy) and selectivities towards C-2-oxygenates (SC2-oxy) than that prepared from the untreated silica support. The enhancement in the hydrophobicity of the pretreated silica supports would be favorable for increasing Rh dispersion and ratio of Rh+/Rh-0 sites, therefore increasing the number of active sites, especially the active sites for CO insertion. Such variations are responsible for the improvements in the catalytic performance of the Rh-Mn-Li/SiO2 catalyst.