Silica‐supported Catalyst System Rh−Mn−Ir−Li−Ti in Syngas to Ethanol Reaction: Reactivity Trends and Performance Optimization

Ethanol is a high‐value chemical that can be produced from syngas derived from fossil or renewable resources. Silica‐supported catalysts based on Rh are reported to show the best performance so far. We report a comprehensive investigation for influence of catalyst composition on performance in syngas conversion to ethanol. We evaluate 53 different silica‐supported catalysts with a varying degree of Rh, Mn, Ir, Li and Ti, via high‐throughput testing. Correlation analysis reveals that Li and Ir tend to increase the selectivity to C2+ oxygenates, and catalysts with a 0.95 molar ratio of Rh : Mn show a tendency for high CO conversion. The composition 2.8Rh, 0.45Mn, 1.3Ir, 0.04Li, where the numbers indicate weight percentage, is identified to yield one of the highest C2+ oxygenate values reported in the literature so far. Moreover, combining this catalyst with a hydrogenation catalyst and converting C2+ oxygenates to ethanol, provides one of the highest ethanol yields reported so far in literature.