CdSO4 and ZnSO4 as co-modifiers of RuLa/SBA-15 lead to improved catalysts for the partial hydrogenation of benzene to cyclohexene. Based on the experimental results and theoretical calculations, it is shown that CdSO4 acts as surface modification, suppressing more the adsorption of cyclohexene than that of benzene, while the function of ZnSO4 is mainly the stabilization of cyclohexene in the liquid phase, accelerating the desorption as well as hindering the re-adsorption of cyclohexene. (C) 2009 Elsevier Inc. All rights reserved.