Oxygen Reduction Performance of Pt/TiO2-C Electrocatalyst prepared by Two-step Chemical Vapor Deposition
Résumé
The low durability of Pt/C electro-catalysts in polymer electrolyte membrane fuel cells (PEMFC), e.g., as a result of carbon oxidation to CO2 in an acid medium, has been recognized as one of the most important hindrances to long-term stability. In this work, Pt electrocatalysts supported on TiO2-carbon and Vulcan carbon were prepared by the chemical vapor deposition method. The physical and electrochemical properties of Pt/TiO2-C and Pt/C electrocatalysts were investigated by the characterization techniques of XRD, TEM, CO stripping and cyclic and linear voltammetry. The prepared materials were electrochemically evaluated in the oxygen reduction reaction (ORR) in an acid medium at room temperature. The XRD results show crystalline fcc platinum formation. The mean particle size is be-tween 2 and 4 nm with a spherical morphology. Pt/TiO2-C electrocatalysts showed a higher electrochemical active surface area and better activity results for the ORR compared with the Pt/C samples. The addition of TiO2 to the conventional Pt/C catalyst modifies the electronic properties affecting the oxygen adsorption and improving the catalytic activity for the oxygen reduction reaction.