Investigation of TiO2/carbon electrocatalyst supports prepared using glucose as a modifier
By Odetola, Christopher; Easton, E. Bradley; Trevani, Liliana
Published in International Journal of Hydrogen Energy
2016
Abstract
Abstract The oxidative treatment of carbon used to increase surface wetness can also make it less stable and more prone to carbon corrosion at high potentials when used in a fuel cell cathode. In this work, we investigate an alternative non-oxidative approach in which a thin film of TiO2 nanoparticles (?10-20 nm) is deposited on pristine carbon using a sol-gel method and glucose as carbon modifier to improve both wetness and dispersal of Pt on the support. The physical and electrochemical properties of Pt on TiO2/glucose doped pristine carbon (TiO2/G-PV) with up to 32% TiO2 were investigated and compared with those obtained for three reference materials: Pt deposited on acid treated carbon (Pt/ATV), glucose-modified carbon (Pt/G-PV), and TiO2 acid-treated carbon (Pt/TiO2/ATV). The beginning of life-electrochemical active surface area (BOL-ECSA) of Pt on TiO2/G-PV with 14% TiO2, 46.2 m2/g Pt, was significantly higher than that for Pt deposited on ATV, with and without TiO2, 16.8 m2/g and 36.3 m2/g, respectively. A similar trend was observed after 4000 potential cycles (0-1.5 V vs. NHE). For all the catalysts studied, kinetic analysis of the composite catalysts towards the oxygen reduction reaction (ORR) indicates a 4-electron transfer process. However, the onset potential for the {ORR} and the kinetic currents were superior for the TiO2/G-PV samples.