Copper-Promoted Cobalt/Titania Nanorod Catalyst for CO Hydrogenation to Hydrocarbons

Abstract

The effect of Cu on cobalt/titania nanorod (Co/TNR) catalysts for the promotion of carbon monoxide (CO) hydrogenation to hydrocarbons was investigated. Varying amounts of Cu (1.5–6.0 wt%) were loaded onto the base Co/TNR catalyst using the deposition–precipitation method. Characterization by X-ray diffraction (XRD) revealed that the Cu particles were well dispersed over the Co/TNR catalysts. Characterizations by temperature-programmed desorption of hydrogen (H2-TPD) and carbon monoxide (CO-TPD) and temperature-programmed reduction in hydrogen (H2-TPR) proved the effect of the Cu promoter in the Co/TNR catalyst by its bimetal effect with Co, where the Co/TNR catalysts containing Cu generally showed a significant improvement in comparison with the base Co/TNR catalyst not containing the Cu promoter. The CO and H2 adsorption capacities and reducibility were optimal on the catalyst containing 1.5% Cu (1.5Cu-Co/TNR). This aligns well with the catalytic activity performance of all the catalysts, where the 1.5Cu-Co/TNR catalyst exhibited the best performance, yielding 16.8% CO conversion and 57.7% C5+ hydrocarbon selectivity at 240 ℃ and 5 bar.