Higher alcohol synthesis over nickel-modified alkali-doped molybdenum sulfide catalysts prepared by conventional coprecipitation and coprecipitation in microemulsions

• A novel K-Ni-MoS2 catalyst was synthetized by coprecipitation in microemulsions.
• The novel catalyst shows better performance than a conventional K-Ni-MoS2 sample.
• Ethanol yield is especially enhanced with the new preparation method.
• The greater enrichment of K and Ni on the surface could explain the improvement.

Ethanol and higher alcohols are one of the most interesting alternatives to replace fossil fuels in the transportation sector. Nickel-modified alkali-doped molybdenum sulfide is a potential catalyst for the conversion of syngas to mixed alcohols. In this work, K-Ni-MoS2 catalysts were synthetized by coprecipitation in aqueous solution or in microemulsions, followed by alkali doping. The influence of the preparation route in CO hydrogenation was investigated at 91 bar, 340/370 °C and GHSV = 2000–14,000 NmL/h gcatalyst. The catalysts were also characterized by TGA, ICP, XPS, nitrogen adsorption, XRD, SEM-EDX and TEM. The novel microemulsion catalyst outperformed the conventional one, resulting in higher yields of ethanol and higher alcohols. The higher activity and selectivity was attributed to a higher concentration of promoters on the microemulsion catalyst surface, together with a lower degree of crystallinity.

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