hrvatski

Elektrokristalizacija Pt-nanočestica na ugljičnim površinama

Carbon supported metal catalysts are of great interest for investigations of many electrocatalytic reactions, especially for fuel cells. Carbon as an inactive conductive substrate facilitates spectroscopic characterization of the nanoparticles. The aim of this work has been to study the mechanism and the kinetics of Pt electrocrystallization process on glassy carbon (GC) and highly oriented pyrolitic graphite (HOPG) substrates in a deaerated 10-3 mol dm-3 hexachloroplatinum solution in 1 mol dm-3 perchlorate solution using cyclic voltammetry, chronoamperometry, and scanning electron microscopy (SEM). From the quantitative analysis of the potentiostatic pulse measurements, relevant kinetic parameters for 3D instantaneous nucleation and growth under diffusion control are determined, the density of the growing nucleation centers was 10^9-10^10 cm^(-2), and the stationary rate of nucleation was 10^(3) s^(-1). Platinum nanoparticles have nucleated both at carbon surface defect sites such as step edges and, on atomically smooth terraces according to the Volmer-Weber mechanism. Finally, the morphological study of Pt nanoparticles was performed by SEM.

platina; staklasti ugljik; visoko orjentirani pirolitički grafit; nukleacija

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