Effect of iron promoter on structure and performance of CuMnZnO catalyst for higher alcohols synthesis

Effect of iron promoter on the microstructures of CuMnZnO catalysts was investigated by N2 physical adsorption (BET), X-ray diffraction (XRD), and temperature-programmed reduction of hydrogen (H2-TPR). Higher alcohols synthesis (HAS) was performed in a fixed bed reactor. The characterization results indicated that incorporation of iron in the CuMnZnO catalyst resulted in the increase of BET surface area and the dispersion of catalyst particles. Adding iron facilitated the formation of Fe–Mn solid solution and reduced the interaction between copper and manganese, which promoted the separation of CuO from the Cu–Mn solid solution and the reduction of the catalyst. In the HAS reaction, the catalytic activity of CO hydrogenation and the selectivity to C2+OH and hydrocarbons presented an increasing trend with the increase in iron concentration, which may be attributed to the synergistic effect between the dispersed copper and iron carbides.

► Incorporation of iron promotes the dispersion of catalyst particles.
► Adding iron facilitates the separation of CuO from the Cu–Mn solid solution.
► Both the copper and iron carbides are well dispersed in higher iron amount.
► The selectivity to C2+OH is promoted by increasing iron concentration.