Carbon nanotube buckypapers as electrocatalysts support for methanol oxidation

J.M. SIEBEN; A. ANSÓN-CASAOS; M.T. MARTÍNEZ; E. MORALLÓN

Cracovia

Congreso; Carbon 2012; 2012

The Polish Carbon Society

Single-walled carbon nanotubes (SWCNTs) are very attractive materials due to their exceptionalgeometry and properties at the nanoscale. SWCNTs exhibit excellent electronic conductivity andsuperior mechanical performance, high surface area, and high chemical stability. The preparationof SWCNT-based films has been up to date the most successful way to transfer SWCNTsproperties from the nano- to the microscale level [1], leading to formation of strong and lightweightmaterials [2]. As a result, buckypapers (BPs) can be considered as very promisingmaterials for catalyst support in fuel cells.This work presents the results of a study which has investigated the use of different BPs ascatalyst supports for methanol electro-oxidation in acid media. Buckypapers were obtained fromas-grown SWCNT suspensions in DMF (BP1), SDBS (BP2) and DMF/PVDF (BP3).Pt-Ru catalysts supported on BPs were prepared by multiple potentiostatic pulses by using adiluted solution of Pt and Ru salts (2 mM H2PtCl6 + 2 mM RuCl3) in acid media. Thenanostructured materials were characterized via SEM, TEM, EDX and ICP-OES analysis. Welldispersed nanoparticles with particle sizes ranging between 5 and 20 nm were successfullyelectrodeposited on the BPs surface. The ruthenium content in the bimetallic deposits was closeto 50 at. %. In addition, the specific surface areas of the catalysts were in the range of 72 to 84 m2g-1.The electrochemical behavior of the different catalysts materials was investigated by cyclicvoltammetry and chronoamperometry experiments in 0.5 M H2SO4 and 1 M MeOH/0.5 M H2SO4solutions at room temperature. Electrocatalytic activity measurements indicated that the mostactive electrode for methanol electro-oxidation was obtained using BP1 as catalyst support,followed by BP3