Single-walled Carbon Nanotube Buckypapers as Electrocatalyst Supports for Methanol Oxidation

SINGLE-WALLED CARBON NANOTUBE BUCKYPAPERS AS ELECTROCATALYST SUPPORTS FOR METHANOL OXIDATION J.M. Sieben, A. Ansón-Casaos, M.T. Martínez, E. Morallón a Departamento de Química Física and Instituto Universitario de Materiales, Universidad de Alicante, Ap. 99 Alicante, Spain. b Instituto de Carboquímica, CSIC, Miguel Luesma 4, 50018 Zaragoza, Spain. Abstract This work studies the use of various single-walled carbon nanotube (SWCNT) buckypapers as catalyst supports for methanol electro-oxidation in acid media. Buckypapers were obtained by vacuum filtration from pristine and oxidized SWCNT suspensions in different liquid media. Pt-Ru catalysts supported on the buckypapers were prepared by multiple potentiostatic pulses using a diluted solution of Pt and Ru salts (2 mM H2PtCl6 + 2 mM RuCl3) in acid media. The resulting materials were characterized via SEM, TEM, EDX and ICP-OES analysis. Well dispersed rounded nanoparticles between 2 and 15 nm were successfully electrodeposited on the SWCNT buckypapers. The ruthenium content in the bimetallic deposits was between 32 and 48 at. %, while the specific surface areas of the catalysts were in the range of 72 to 113 m g. It was found that the solvent used to prepare the SWCNT buckypaper films has a strong influence on the catalyst dispersion, particle size and metal loading. Cyclic voltammetry and chronoamperometry experiments point out that the most active electrodes for methanol electro-oxidation were prepared with the buckypaper supports that were obtained from SWCNT dispersions in N-methylpyrrolidone.