The effect of a copper modifier on physicochemical properties of coprecipitated precursors and final Ni-Cu/Al2O3 catalysts for benzene to cyclohexane hydrogenation was investigated. Based on the studies of physicochemical properties, the influence of copper on the catalytic activity and selectivity of Ni-Cu/Al2O3 systems was discussed. The addition of copper resulted in a decrease of the specific and nickel surface area, improvement of the selectivity and a slight decrease of the benzene hydrogenation activity compared to the reference catalyst. A decrease of methylcyclopentane and methylcyclohexane by-products formation on the surface of Ni-Cu/Al2O3 catalyst containing 10-17 wt% CuO by, respectively, 70% and 10% was observed. The results reveal a distinct, beneficial effect of the Ni/Al2O3 modification by copper on the catalyst selectivity. However, this effect depends on temperature and is limited to ca. 20 wt% CuO, above this content the activity was found to decrease considerably. (C) 2016 Elsevier B.V. All rights reserved.