A study has been made of the relationships governing the catalytic action, special features, and scope for use of the bifunctional systems Pd-amorphous aluminosilicate and Pd-zeolite (HY, M(n)+NaY, H-pentasil) in the synthesis of sec-butylbenzene (SBB) from benzene and ethylene at a pressure of 0.1 MPa and 100-200-degrees-C. It has been shown that, by changing the ratio of the dimerizing and alkylating functions of the catalyst, and also the process conditions, it is possible to direct the interaction of the reactants towards the formation mainly of SBB or SBB and C4-C6 olefins, achieving a selectivity of conversion of ethylene to the given products of 80-92%. Pd-zeolite contacts are compared with Ni-zeolite systems previously investigated.