Polypyrrole-Modified-Carbon-Supported Ru-Pt Nanoparticles as Highly Methanol-Tolerant Electrocatalysts for the Oxygen-Reduction Reaction

• Published in: ChemCatChem Vol. 5; no. 12; pp. 3680 - 3689
• Main Authors: Escudero Cid, Ricardo, Gómez de la Fuente, José Luis, Rojas, Sergio, García Fierro, José Luis, Ocón, Pilar
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.12.2013; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Carbon; Fuel cells; nanoparticles; Oxygen; platinum; ruthenium; supported catalysts
• ISSN: 1867-3880; 1867-3899
• DOI: 10.1002/cctc.201300448

The modification of mesoporous carbon black with polypyrrole (C‐PP) facilitates the incorporation of homogeneously dispersed nanosized Ru‐Pt particles (1–2 nm) onto the support. Polypyrrole‐modified carbon supports were prepared by the addition of different amounts of pyrrole, followed by in situ polymerization through oxidative treatments. The Ru‐Pt/C‐PP electrocatalysts were tested in the oxygen‐reduction reaction in methanol‐containing acidic electrolytes by using both conventional electrochemical techniques and in a direct methanol single cell. The performance of Ru‐Pt/C‐PP was far superior to that of Pt/C for the oxygen‐reduction reaction in the direct methanol fuel cell. Under severe methanol‐crossover conditions, the maximum power density that was delivered by Ru‐Pt/C‐PP after degradation tests was decreased by 20 %, whereas that of Pt/C decreased by 75 %. Thus, the presence of Ru oxides in the cathode led to more tolerant electrocatalysts towards the presence of methanol in the reaction medium during the oxygen‐reduction reaction. With ORR without you: A carbon‐supported Ru‐Pt electrocatalyst exhibits superior methanol tolerance than Pt/C during the oxygen‐reduction reaction, thus leading to more active and durable direct methanol fuel cells. Modification of the carbon support with polypyrrole allows for better dispersion of the Ru‐Pt nanoparticles.