Oxygen reduction reaction catalyzed by platinum nanonetwork prepared by template free one step synthesis for polymer electrolyte membrane fuel cells

• Published in: Materials research bulletin Vol. 55; pp. 137 - 145
• Main Authors: Narayanamoorthy, B., Kumar, B.V.V.S. Pavan, Eswaramoorthy, M., Balaji, S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.07.2014
• Subjects: Catalytic properties; CURRENT DENSITY; ELECTROCATALYSTS; Electrochemical measurements; ELECTROLYTES; HARDNESS; MATERIALS SCIENCE; NANOSCIENCE AND NANOTECHNOLOGY; NANOSTRUCTURES; OXYGEN; PLATINUM; POLYMERS; REACTION KINETICS; SOL-GEL PROCESS; Sol–gel chemistry; SURFACE AREA; SYNTHESIS; TRANSMISSION ELECTRON MICROSCOPY; Catalytic properties; Electrochemical measurements; Transmission electron microscopy; Nanostructures; Sol–gel chemistry
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2014.04.005

[Display omitted] •Supportless Pt nanonetwork (Pt NN) synthesized by novel template free one step method as per our earlier reported procedure.•Electrocatalytic activity of Pt NN studied taking oxygen reduction reaction in acid medium.•Kinetic and thermodynamic parameters were deduced under hydrodynamic conditions.•ORR mechanistic pathway was proposed based on kinetic rate constants.•ADT analysis found enhanced stability (5000 cycles) for Pt NN than Pt NN/VC and reported Pt/C. The reduction reaction of molecular oxygen (ORR) was investigated using supportless Pt nanonetwork (Pt NN) electrocatalyst in sulfuric acid medium. Pt NN was prepared by template free borohydride reduction. The transmission electron microscope images revealed a network like nano-architecture having an average cluster size of 30nm. The electrochemical characterization of supportless and Vulcan carbon supported Pt NN (Pt NN/VC) was carried out using rotating disc and ring disc electrodes at various temperatures. Kinetic and thermodynamic parameters were estimated under hydrodynamic conditions and compared with Pt NN/VC and reported Pt/C catalysts. The accelerated durability test revealed that supportless Pt NN is quite stable for 5000 potential cycles with 22% reduction in electrochemical surface area (ECSA). While the initial limiting current density has in fact increased by 11.6%, whereas Pt NN/VC suffered nearly 55% loss in ECSA and 13% loss in limiting current density confirming an enhanced stability of supportless Pt NN morphology for ORR compared to conventional Pt/C ORR catalysts in acid medium.