Plasma sputtering deposition of platinum on porous substrates is a relevant way for building high performance catalytic thin films. The knowledge and control of platinum density adsorbed in the porous medium, during deposition, are of primary importance. We show that the experimental concentration depth profiles originate from a superdiffusion phenomenon. Moreover experimental results are well described by a classical porous-fractal diffusion model, for which diffusion coefficient is also time-dependent, even if such a model does not include the proper physical mechanisms.