Carbon-Supported Ordered Pt-Ti Alloy Nanoparticles as Durable Oxygen Reduction Reaction Electrocatalyst for Polymer Electrolyte Membrane Fuel Cells

Abstract

Carbon-supported ordered Pt-Ti alloy nanoparticles were prepared as a durable and efficient oxygen reduction reaction (ORR) electrocatalyst for polymer electrolyte membrane fuel cells (PEMFCs) via wet chemical reduction of Pt and Ti precursors with heat treatment at 800 o C. X-ray diffraction analysis confirmed that the prepared electrocatalysts with Ti precursor molar compositions of 40% (PtTi40) and 25% (PtTi25) had ordered Pt 3 Ti and Pt 8Ti structures, respectively. Comparison of the ORR polarization before and after 1500 electrochemical cycles between 0.6 and 1.1 V showed little change in the ORR polarization curve of the electrocatalysts, demonstrating the high stability of the PtTi40 and PtTi25 alloys. Under the same conditions, commercial carbon-supported Pt nanoparticle electrocatalysts exhibited a negative potential shift (10 mV) in the ORR polarization curve after electrochemical cycling, indicating degradation of the ORR activity.