Abstract
Catalytic conversion of syngas into high value-added chemicals such as higher alcohols (C2+OH) are vitally crucial in chemical industry but still remains a challenge due to the low conversion and C2+OH selectivity. Herein, the combination of powerful CO activation on ZnCr-based sites and strong C-C coupling for chain propagation on KNiMoS is highly desirable to achieve high C2+OH yield on hierarchical KNiMoS vertical bar ZnCrAlS-based multifunctional catalysts. The hierarchical structure can facilitate the dispersion of MoS2 slabs with dominant double-layer stacking to enable the high sulfuration degree of Mo and high proportion of NiMoS active phases due to the appropriate metal-support interaction. As a result, KNiMoS vertical bar ZnCrAlS-O(E) showed the highest CO conversion (20.2 %), total alcohols selectivity (63.8 %) with high C2+OH/ROH fraction of 68.5 %, TOF (176.8 h(-1)), STY (116.4 mg g(-1)h(-1)) and excellent stability. A plausible reaction path was also proposed on hierarchical KNiMoS vertical bar ZnCrAlS-O(E) multifunctional catalyst that the alkoxy intermediates species formed on ZnCr active species can partially transform to MoS2-based active phase to form CHyCHxO* species for the favourable C2+OH synthesis. This work offers a promising strategy through the integration of multifunctional catalyst with hierarchical pore to strengthen CO activation and C-C coupling for selective conversion of syngas to C2+OH.