Fe promoted Rh–Mn/Al2O3 catalysts with different Fe impregnation sequences were used for ethanol
formation from syngas. The effect of Fe impregnation
sequence on the structure and performance of the catalysts
was investigated by means of N2 adsorption, CO adsorption, H2-TPR, H2-TPD, CO-TPD, XPS and DRIFTS. The
results showed that the RhMnFe/Al2O3 catalyst prepared
by co-impregnation method showed higher ethanol selectivity than those prepared by sequential impregnation
methods. Characterization results indicated that the
RhMnFe/Al2O3 catalyst exhibited moderate CO hydrogenation and dissociation ability, stronger CO insertion
ability and synergistic effect, which was responsible for its
higher ethanol selectivity.

• Effect of Fe impregnation sequence on ethanol synthesis from syngas over Mn and Fe promoted Rh/c-Al2O3