Titania supported platinum catalyst with high electrocatalytic activity and stability for polymer electrolyte membrane fuel cell

Titania supported Pt electrocatalysts (Pt/TiO2) were synthesized and investigated as alternative cathode catalysts for polymer electrolyte membrane fuel cells (PEMFCs). Transmission electron microscope (TEM) images revealed uniform distribution of Pt nanoparticles (d(Pt) = 3-5 nm) on the TiO2 support. The Pt/TiO2 electrocatalyst showed comparable activity to that of a commercial Pt/C catalyst (TKK) in fuel cell studies. The fuel cell accelerated stress test (AST) for catalysts demonstrated similar stability for Pt/TiO2 and Pt/C. In-house developed accelerated durability test (ADT, continuous potential cycling between 0.6 and 1.4 V) in half-cell condition indicated nearly ten-fold higher ORR activity (1.20 mA cm(-2)) when compared to the Pt/C catalyst (0.13 mA cm(-2)). The Pt/C catalyst showed no activity in fuel cell testing after 2000 potential cycles due to severe carbon corrosion. Pt dissolution, and catalyst particle sintering. Conversely, the Pt/TiO2 electrocatalyst showed only a small voltage loss (0.09 V at 0.8 A cm(-2)) even after 4000 cycles. Furthermore, the ADT results showed excellent stability for the Pt/TiO2 electrocatalysts at high potentials in terms of minimum loss in the Pt electrochemical surface area (ECSA). The high stability of the Pt/TiO2 electrocatalyst synthesized in this investigation offers a new approach to improve the reliability and durability of PEM-based fuel cell cathode catalysts. (C) 2010 Elsevier B.V. All rights reserved.