Approaches and nature of improving Rh-based catalyst performance for CO hydrogenation to C2-oxygenates

Thermodynamic analysis results revealed that the formation of C-2-oxygenates from syngas is much more unfavorable than the formation of hydrocarbons. Therefore, the crucial and effective method to promote the C-2-oxygenate synthesis is to develop high selective catalysts. According to the mechanism of C-2-oxygenate formation, the natures and the approaches to improve the catalytic performance of the Rh-based catalyst for CO hydrogenation to C-2-oxygenates were the improvement and the balance in CO dissociation and insertion activity, the proper hydrogenation activity, and the optimal Rh size on the catalyst surface. The impregnation and reduction conditions were optimized to suppress correctly the catalytic activity of the Rh-Mn-Li-Fe/SiO2 catalyst for CO hydrogenation. Consequently, CO insertion competed favorably with hydrogenation, resulting in a maximum selectivity (91.6% In mass fraction) for C-2-oxygenates with a high yield and a much low methane selectivity (6.3% in mass fraction).