LaFeO3-supported nano Co-Cu catalysts for higher alcohol synthesis from syngas

To produce Co-Cu catalysts supported on perovskite-type oxides of LaFeO3, we prepared LaFe0.7Cu0.3O3 according to the citrate complexation method; the impregnation method was used to load cobalt oxide onto the support. The Co3O4/LaFe0.7Cu0.3O3 catalysts were characterized by XRD, TEM, TPR, XPS and SBET analysis, and were used to catalyze the synthesis of alcohol from syngas. Copper ions in the perovskite lattice were easily segregated by pre-reduction, which resulted in the formation of nano-sized copper metal. The copper nano-particles catalyzed the reduction of Co3O4, which led to the production of highly dispersed copper nano-particles covered by a metallic cobalt shell of core–shell structure Cu@Co and Cu-Co alloy supported on perovskite-type oxides of LaFeO3. During the reaction, Cu-Co and La2O3 facilitated the formation of Co2C, and the phase of the catalyst precursor changed to Co2C-Cu/La2O2CO3-LaFeO3. The prepared catalysts were highly active, selective and stable during the synthesis of alcohol from syngas. The high activity and selectivity of the catalysts were attributed to the presence of copper-modified Co2C species, which were highly dispersed nano-particles located on the LaFeO3 surface. The good stability of the catalysts was attributed to the interactions between Co2C-Cu nano-particles and their support.

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► Strong interactions between Co3O4 and the support exist in Co3O4/LaFe0.7Cu0.3O3.
► Co3O4/LaFe0.7Cu0.3O3 can be reduced to Cu-Co or Cu@Co/La2O3-LaFeO3.
► Co in Cu-Co or Cu@Co/La2O3-LaFeO3 can be carbonized to Co2C during reaction.
► Co2C is the active site to higher alcohol synthesis.
► Cu-Co2C/La2O2CO3-LaFeO3 catalyst possesses high activity and good stability.