Electrocatalysts tantalum

It is known that deposition on substrates where nonconductive metal oxide layers are formed at positive potentials is difficult. This includes electrodes made of stainless steel, tantalum, and aluminum. However, the rate of oxide formation is important because we have shown that stainless steel is an ideal substrate for deposition of some PPy s. The rate of oxide formation depends on the solution and the electrochemical conditions employed. If the polymer can deposit before the onset of metal oxide formation, then consistent films of excellent quality can be deposited. This is aptly demonstrated with the successful electrocoating of aluminum when the electrocatalyst Tiron 4 is used. 

Baturina OA, Garsany Y, Zega T, Stroud R, Schull E, Swider-Lyonsa KE (2008) Oxygen reduction reaction on platinum/tantalum oxide electrocatalysts for PEM fuel cells. J Electrochem Soc 155 B1314—B1321... 

One of the highest activity electrocatalysts to be reported in recent years is Pt supported on tantalum oxyphosphate (TOPh)-coated Vulcan XC-72 [164]. This catalyst support is different than the others discussed above since TOPh has quite low electronic conductivity. It was suggested by Garsany and coworkers that the carbon core provides particle-to-particle electronic conductivity, while the very thin TOPh layer interacts with the Pt nanoparticles, manipulating their activity and stability. Linear sweep voltammograms for the Pt/TOPh/C electrode in 02-saturated perchloric acid are shown in Fig. 24.20a. 

Garsany Y, Epshteyn A, Purdy AP, More KL, Swider-Lyons KE (2010) High-activity, durable oxygen reduction electrocatalyst nanoscale composite of platinum-tantalum oxyphosphate on vulcan carbon. J Phys Chem Lett 1(13) 1977-1981... 

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