Effect of preparation method on CuZnAl catalysts for ethanol synthesis from syngas

CuZnAl catalysts without promoters were prepared by traditional method and complete liquid-phase method. Activity tests indicated that the catalysts prepared by complete liquid-phase method could efficiently catalyze syngas to ethanol and the selectivity to ethanol reached approximately 30%, comparatively, the catalyst prepared with traditional method exhibited high CO conversion with the liquid products being mainly composed of methanol. Characterization results showed that preparation method affected the composition and microstructure of the catalysts as well as the interaction among Cu, Zn, and Al species. It was also found that the existence of Cu+ and the strong weak acid on the catalysts surface was necessary for ethanol synthesis from syngas. This work provided a new concept that carbon chain could grow over CuZnAl catalysts without other promoters. (C) 2015 Elsevier B.V. All rights reserved.