Characterization of fused Fe-Cu based catalyst for higher alcohols synthesis and DRIFTS investigation of TPSR

Fused Fe-Cu based catalyst for higher alcohols synthesis (HAS) is characterized by XRD, TG-DTA, H-2-TPD and DRIFTS of CO adsorption. The results of XRD reveal that the fused Fe-Cu based catalyst consists of Cu2O. CuFeO2 and CuFe2O4 species. After reduction, the metallic Fe and Cu are the main species, but minor CuFeO2 and CuFe2O4 species are also present. H-2-TPD shows that in comparison with the pure Fe- or Cu-based sample, the ability of Fe-Cu based catalyst for activation of H-2 is higher and the stronger metal-hydrogen bonds are formed. DRIFTS of CO adsorption indicates that CO is adsorbed on both metal and metal ion sites, where the dissociation of CO to C* and O* species and the formation of CO2 are observed. In situ DRIFTS investigation of CO + H-2-TPSR over the Fe-Cu based catalyst shows that the dissociative activation of H-2 is more difficult than the activation of CO, and carbonaceous and hydrocarbon fragment species only appears after the dissociative activation of H-2. In addition, HAS over the Fe-Cu based catalyst is very complicated, where various intermediates including =CH2, - CHO, - OOCH, - OH and - C(=O)-R exist. (C) 2010 Elsevier B.V. All rights reserved.