Mixed Oxide Supports Derived From Layered Metal Hydroxides to Reduce Methanol Selectivity In the Catalytic Synthesis of Higher Alcohols Over Potassium-Promoted Molybdenum Sulfide Catalysts

Molybdenum sulfide, a well-known hydrodesulphurization catalyst, is being increasingly investigated as a catalyst for conversion of synthesis gas to higher alcohols. Here it is demonstrated that potassium promoted MoS₂ catalysts supported on basic, mixed metal oxides derived from decomposed, synthetic hydrotalcites convert syngas into higher alcohols with reduced methanol and increased n-propanol selectivity relative to bulk molybdenum sulfide or conventionally supported molybdenum sulfide catalysts (activated carbon, basic sepiolite clay, or alumina). This advantage may be attributed to the basic, mesoporous nature of the mixed metal oxide support.  X-ray absorption spectroscopy shows that before sulfidation, the molybdenum oxide domains on the supported catalyst are highly dispersed. Treatment of this oxide catalyst at 723 K in 20% hydrogen sulfide in hydrogen results in the formation of molybdenum sulfide moieties that in turn provide a favorable environment for higher alcohol formation.