K-modified NiMoS/ZnAl oxide catalysts for higher alcohols synthesis from syngas

Improving the C₂₊ alcohols yield is highly desirable for the direct synthesis of higher alcohols from syngas. In this work, a series of highly dispersed K-modified NiMoS catalysts with different K contents on ZnAl-mixed oxide support were prepared by the combination of co-precipitation and impregnation method. And their performance in higher alcohols synthesis (HAS) from syngas was investigated. The results show that the introduction of K can modulate the stacking degree of MoS₂ slabs, and improve the interaction between NiS_x and NiMoS phases. The as-prepared catalyst is conducive to promote the insertion of CH_x and non-dissociative CO in HAS, and effectively suppress the generation of hydrocarbons and CO₂. The 0.6KNiMoS/ZnAl catalyst exhibits the most double-layer MoS₂ slabs (33.7%) and highly synergetic effects between NiS_x and NiMoS to achieve the total alcohols selectivity (69.8%) and space-time yield (78.6 mg/(g·h)) of C₂₊ alcohols.