Six-dimensional classical dynamics simulations are carried out to study the dissociative adsorption of Hz on a Pd(lll) surface. The 6D potential energy surface (PES) used in the simulations is constructed by interpolation of ab initio results. The high accuracy of the PES construction is ascertained by comparison with a set of ab initio data which are not used in the interpolation. We obtain a non monotonic variation of the dissociative adsorption probability with normal incident energy as found experimentally. Our results provide further support to the importance of dynamical steering.