A Ru-Sn-Co/AlO(OH) catalyst was prepared by co-impregnation, calcination, and hydrothermal reduction. The catalyst was well characterized by BET, XRD, SEM-EDX, XPS, H-2-TPR, and Mossbauer spectroscopy, and then it was applied in the hydrogenation of dimethyl adipate to 1,6-hexanodiol in aqueous phase. It was found that the addition of cobalt could stabilize Sn(IV) and the cooperation between tin and cobalt could promote the reduction of ruthenium oxide. The gamma-Al2O3 in the catalyst Ru-Sn-Co/gamma-Al2O3 was transformed to AlO(OH) by the hydrothermal reduction. It was suggested that the stabilized Sn(IV) and the interaction between the hydroxyl group on the surface of AlO(OH) and the solvent water played a key role to improve the conversion of dimethyl adipate and the selectivity to 1,6-hexanodiol. The conversion of dimethyl adipate and the selectivity to 1,6-hexanodiol were up to 98% and 95%, respectively, under 5 MPa of H-2 and 493 K for 10 h. (C) 2012 Elsevier B.V. All rights reserved.