Enhanced Higher Alcohol Synthesis from CO Hydrogenation on Zn-Modified MgAl-Mixed Oxide Supported KNiMoS-Based Catalysts

A highly dispersed KNiMo catalyst on Zn-modified MgAI-mixed oxide as a support is prepared by a surfactant-assistance hydrothermal method. The introduction of Zn can decrease the concentration of strong acidic sites and also can weaken the metal-support interaction to modulate the reducibility, sulfidation degree, lengths/stacking degree, and dispersion of MoS2 slabs. The K,NiMoS/Zn0.35Mg0.35Al0.3 exhibits appropriate acidity, high reducibility, and a sulfidation degree with dominant double-layer MoS2 (similar to 43%) and high synergism between NiSx and K-Ni-Mo-S phase, and as a result, higher total alcohol selectivity (56.5%) and C2+ alcohol selectivity (82.2%) can be achieved in higher alcohol synthesis (HAS). This work proposes an effective route to simultaneously modulate the acidity of the catalyst and metal-support interaction and to obtain more exposure of active sites on the integration of Zn-modified MgAl-mixed oxides as supports and a surfactant-assistance strategy for the enhancement of C2+OH selectivity in HAS.