Investigation of TiO2/carbon electrocatalyst supports prepared using glucose as a modifier

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 (similar to 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 m(2)/g Pt, was significantly higher than that for Pt deposited on ATV, with and without TiO2, 16.8 m(2)/g and 36.3 m(2)/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. (C) 2015 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.