Effect of Cu content on the surface and catalytic properties of Cu/ZrO2 catalyst for ethanol dehydrogenation

ZrO2-supported Cu catalysts with different Cu content (5-30 wt.%) were prepared by impregnation method. The effect of Cu content on the structure, surface and catalytic properties of Cu/ZrO2 catalysts in the reaction of ethanol conversion was studied. The physicochemical characterization of the calcined and reduced samples was carried out by: N-2 adsorption-desorption isotherms, N2O titration, XRD, XPS, TPR and DRFTS of CO adsorption. It was observed that the increase of Cu content leads to decrease of the apparent copper metal dispersion caused by the strong agglomeration of the metal particles. The selectivity to different reaction products was connected with the electronic properties of the catalysts defined by the copper particle size and the interface at metal-oxide support. The highest selectivity to ethyl acetate over samples with Cu content >= 10 wt.% was assigned to the high density of basic sites of O2- ions and more heterogeneous distribution of copper species (Cu-0/Cu+) defined by DRIFTS of CO adsorption and XPS. (C) 2013 Elsevier B.V. All rights reserved.