Electroreduction of molecular oxygen on preferentially oriented platinum electrodes in acid solution

• Autores: Zinola Sánchez, Carlos Fernando; Castro Luna Berenguer, Ana María del Carmen; Triaca, Walter Enrique; Arvia, Alejandro Jorge
• Año de publicación: 1994
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Física; Química; oxygen electroreduction; conventional polycrystalline
• Institución: Universidad Nacional de La Plata

The oxygen electroreduction reaction was studied on two different preferentially oriented ((111)-type and (100)-type and on a conventional polycrystalline (PC) platinum rotating disc electrodes in acid solutions at 30 °C. At low overpotentials, Tafel lines of −0.060 V decade−1 were obtained on the three electrodes in oxygen-saturated 1.0m H2SO4 and 1.0m H2SO4 + y; m K2SO4 (0 ⩽y ⩽ 1). At high over-potentials the usual Tafel slope of -0.120V decade−1 was observed on both (111)-type and PC platinum electrodes in 1.0m H2SO4, whereas a slope of −0.165V decade−1 was found on (100)-type platinum. In oxygen-saturated 1.0m H2SO4 the surface coverage by O-containing adsorbates on (100)-type platinum was greater than on both (111)-type and PC platinum. Rotating ring-disc electrode data showed that a higher amount of H2O2 was produced on (100)-type platinum than on the other platinum surfaces. The overpotential against current density plots are influenced by the anion concentration depending on the type of preferentially oriented platinum.
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas