Effects of Li Promoter on the Performance of Co/AC Catalysts for CO Hydrogenation to Mixed Linear α-Alcohols

The effect of Li promoter on the catalytic performance of the activated carbon (AC) supported cobalt catalysts (Co/AC) for CO hydrogenation was investigated by means of CO hydrogenation, X-ray diffraction (XRD), temperature-programmed reduction (H-2-TPR), and temperature-programmed desorption of adsorbed CO (CO-TPD). The results showed that the addition of Li significantly suppressed the formation of gaseous hydrocarbons and remarkably improved the selectivities for higher hydrocarbons (C5+) and mixed linear alpha-alcohols (C-1-C-18) of CO hydrogenation over the Co/AC catalyst. However, the activity of CO hydrogenation decreased gradually with the increase of Li loading in the Co-based catalyst. H-2-TPR and CO-TPD results illuminated that the existence of Li decreased the reducibility of Co2+ and the ability of CO dissociation, which was the rate-determining step. XRD results indicated that the existence of Li promoter enhanced the formation of Co2C species.