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

摘要

This work was carried out to explore the effect of TiO2 on activity and stability of a PtCo/C catalyst foran oxygen reduction reaction (ORR). Two types of TiO2, including commercial TiO2 (TCOM) and ahome-prepared TiO2 by chemical vapor deposition (TCVD), were incorporated on the PtCo/C catalystlayer. The activity of all prepared-catalysts was tested in a single proton exchange membrane (PEM)fuel cell under an H2/O2 environment at ambient pressure, while their stability was tested by the linearsweep voltammetry (LSV) in 0.5 M H2SO4. The preliminary results demonstrated that the TCVDpromoted PtCo/C catalyst (TCVD-PtCo/C) exhibited the highest activity in a PEM fuel cell for bothactivation polarization and ohmic polarization regions, which can produce the current density of 4342 2 2 mA/cm (277 mW/cm or 1,847 W/gPtm ) at 0.6 V. It also exhibited the highest stability in 0.5 MH2SO4 with performance loss of around 40% after 6,000 LSV-cycles.