Nanostructured NiMoS2/Carbon Catalysts for Syngas Conversion to Higher Alcohols

Abstract

Syngas conversion to higher alcohols remains a very attractive alternative due to the abundance of syngas feedstock, such as renewable carbon and waste-carbon resources. Catalysts suitable for syngas conversion still show low selectivity to alcohols. In this article, we present nanostructured NiMoS2 and CoMoS2 catalysts supported on activated carbon pellets and design strategies to improve its selectivity towards higher alcohols. Activated carbon pellets were treated with concentrated HNO3 to enlarge porous channels and enable better dispersion of NiMoS2 and CoMoS2. These treatment steps lead to a formation of nanostructured NiMoS2 and CoMoS2 catalysts and promoted higher selectivity to ethanol, propanol and butanol. BET surface area of 532 m2 g−1 was obtained for NiMoS2/Carbon catalysts from the nitrogen physisorption analysis. In catalytic tests, the highest CO conversion (39.1%) was achieved by the NiMoS2/Carbon, whereas the CoMoS2/Carbon showed the highest alcohol selectivity (74.4%). CoMoS2 catalysts supported on activated carbon pellets proved to be highly active towards undesired by-product “filamentous carbon.”