Stability of TiO2 Promoted PtCo/C Catalyst for Oxygen Reduction Reaction

This work was carried out to explore the effect of TiO2 on activity and stability of a PtCo/C catalyst for an oxygen reduction reaction (ORR). Two types of TiO2, including commercial TiO2 (T-COM) and a home-prepared TiO2 by chemical vapor deposition (T-CVD), were incorporated on the PtCo/C catalyst layer. The activity of all prepared-catalysts was tested in a single proton exchange membrane (PEM) fuel cell under an H-2/O-2 environment at ambient pressure, while their stability was tested by the linear sweep voltammetry (LSV) in 0.5 M H2SO4. The preliminary results demonstrated that the T-CVD promoted PtCo/C catalyst (T-CVD-PtCo/C) exhibited the highest activity in a PEM fuel cell for both activation polarization and ohmic polarization regions, which can produce the current density of 434 mA/cm(2) (277 mW/cm(2) or 1,847 W/gPt. cm(2)) at 0.6 V. It also exhibited the highest stability in 0.5 M H2SO4 with performance loss of around 40% after 6,000 LSV-cycles.