K/Ni/β-Mo 2C: A highly active and selective catalyst for higher alcohols synthesis from CO hydrogenation

Abstract

Nickel and potassium promoted β-Mo 2C catalysts were prepared for CO hydrogenation to higher alcohols synthesis. The results revealed that β-Mo 2C produced mainly hydrocarbons, but the addition of potassium resulted in a remarkable selectivity shift from hydrocarbons to alcohols over β-Mo 2C. Moreover, it was found that potassium enhanced the ability of chain propagation of β-Mo 2C catalyst and led to a higher selectivity to C 2 +OH. The addition of nickel further enhanced higher alcohols synthesis, which showed the optimum at 1/8–1/6 of Ni/Mo molar ratios. The characterization suggested that there might be a synergistic effect of potassium and nickel on β-Mo 2C, which favored the alcohols synthesis. The production of alcohols appeared to be relevant to the presence of Mo 4+ species, whereas the formation of hydrocarbons was closely associated with Mo 2+ and/or Mo 0 species on the surface of β-Mo 2C-based catalysts.