Pd Nucleation and Growth Mechanism Deposited on Different Substrates

Palladium, has an unique property between the noble metals, that is the higher capacity to adsorb onto the surface, and within its network, the hydrogen, resulting the Pd of crucial importance to many industrial processes such as catalysis, fuel cell, hydrogen storage and metal brittlement.Since the activity of a noble metal deposited depends strongly on the surface structure, this work is focalized to study the Pd° nucleation and growth mechanisms onto different substrates such as HOPG, and thin pure titanium films. Thus, the constant potential method wasused in the nanostructures formation varying the potentials and times.The resulting material was characterized electrochemically and morphologically using scanning electron microscopy (SEM), X-ray diffraction (XRD). In agreement with the results, the existing mechanism onto both substrates, was (3D) Pd° instantaneous nucleation and growth controlled by diffusion, with a development of nanoparticles with defined morphology and narrow size distributions, which are potentially useful as electrocatalysts.