Sunday, February 21, 2010

Cheap alternative for Platinum fuel cell catalyst

Electrocatalysis is central to the further development of proton-exchange membrane (PEM) electrolyzers and PEM fuel cells, which can operate as compact units for powering homes or vehicles. A single device could both store energy by generating hydrogen during times of electrical surplus and release energy by oxidizing the hydrogen fuel at times of excess demand. Today, this goal is best achieved with expensive, noble metal catalyst Platinum. It is a relatively rare and expensive precious metal that has pushed up the price of fuel cells, limiting their wider application. Reversible catalysts based on abundant materials are essential for such devices to have a substantial impact on sustainable energy systems. Le Goff et. al. report (see Ref) a hydrogen electrode based on nickel, an abundant element, in which the catalyst is immobilized on a carbon nanotube support. The cathode material’s high surface area and high catalytic activity produces H2 from aqueous sulfuric acid at very low voltages. The catalyst is also exceptionally stable. This catalyst also effects the reversible inter-conversion between hydrogen ions (H+) and hydrogen (H2) under aqueous conditions. The nanotubes play a key role by providing the catalyst with electrons or removing them in the reverse reaction. The research provides an important initial step toward a practical, non-noble metal hydrogen electrode.

Ref: Alan Le Goff, Vincent Artero, Bruno Jousselme, Phong Dinh Tran, Nicolas Guillet, Romain Métayé, Aziz Fihri, Serge Palacin, Marc Fontecave, “From Hydrogenases to Noble Metal–Free Catalytic Nanomaterials for H2 Production and Uptake”, Science 4 December 2009, Vol. 326. No. 5958, pp. 1384 - 1387


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