B. Rajesh

Nanostructured Conducting Polyaniline Tubules as Catalyst Support for Pt Particles for Possible Fuel Cell Applications

Nanotubules of polyaniline synthesized by template method on commercial carbon cloth have been used as the catalyst support for Pt particles for electro-oxidation of methanol. The ohmic and the charge transfer resistancesof the nanotube-based electrode were considerably lower than the polyaniline electrode synthesized by the conventional route. The Pt incorporated polyaniline nanotube electrode exhibited excellent catalytic activity and stability compared to the 20 wt % Pt supported on the VulcanXC 72R carbon and Pt supported on the conventional polyaniline electrode. The electrode fabrication used in the present investigation is particularly attractive to adopt in the solid polymer electrolyte-based fuel cells, which is usually operated under methanol or hydrogen.

Materials for polymer electrolyte fuel cells

The commercial success of the polymer electrolyte fuel cell (PEFC) will to a large extent be determined by the nature, properties, functionality, and cost of the electrochemical sub-components used in the membrane electrode assembly (MEA). Materials research activities in Switzerland for the PEFC are being pursued at the Paul Scherrer Institut (Villigen AG) and the Swiss Federal Institute of Technology in Lausanne with different objectives. The radiation grafted proton exchange membrane developed at the Paul Scherrer Institut (PSI) has been brought to a near-product-like quality level with encouraging performance close to state-of-the-art materials and a life-time of several thousand hours. Furthermore, the membrane shows low methanol crossover in the direct methanol fuel cell. In addition, polyarylene block copolymer membranes have been investigated as an option for fluorine-free membranes. The electrocatalysis of Pt in acidic solution and in contact with a solid electrolyte, the development of new methanol oxidation and oxygen reduction catalysts, and co-sputtering of Pt and carbon as an alternative method for catalyst preparation are areas of fundamental research. More applied research is performed in the characterization of commercial electrodes in single cells, using standard as well as advanced diagnostic tools developed in-house. This article gives an overview over the research and development projects in Switzerland related to materials and components for the PEFC.

Conducting polymeric nanotubules as high performance methanol oxidation catalyst support

Pt nanoparticle-supported conducting nanotubules of polypyrrole prepared by a template method exhibited excellent catalytic activity and stability for the electrooxidation of methanol in comparison to Pt supported on conventionally synthesised conducting polypyrrole.

Pt supported on Polyaniline-V2O5 nanocomposite as the electrode material for methanol oxidation

The nanocomposite material prepared via the intercalation of polyaniline in matrix has been used as the support for Pt in methanol oxidation reaction. The average particle size of the Pt as evaluated from the high-resolution transmission electron microscope was found to be 4 nm. The X-ray photoelectron spectroscopy analysis revealed that vanadium is present in the form of and Pt in the metallic state. The activity of methanol oxidation of the Pt loaded nanocomposite electrode as evaluated from cyclic voltammetry was found to be at vs. Ag/AgCl for a Pt loading of The chronoamperometric response reveals the better activity and stability of the nanocomposite electrode compared to the bulk Pt electrode.

Preparation of Pt-Ru bimetallic catalyst supported on carbon nanotubes

The template carbonization of polyphenyl acetylene yields hollow, uniform cylindrical carbon nanotubes with outer diameter almost equal to pore diameter of the template used. High resolution transmission electron microscopic investigation reveals that Pt-Ru nanoparticles are highly dispersed inside the tube with an average particle size of 1.7 nm.