Fluorinated polyanilines as superior materials for electrocatalytic anodes in bacterial fuel cells

In a recent communication we demonstrated that electrodes consisting of a platinum electrocatalyst covered by a conductive polymer like polyaniline are well suited to serve as anodes harvesting electricity in microbial fuel cells [Angew. Chem. Int. Edn. 42 (2003) 2880]. In this communication we show that the fluorinated polyanilines poly(2-fluoroaniline) and poly(2,3,5,6-tetrafluoroaniline) outstrip the parent compound polyaniline in their performance as an electrode modifier. Similar to polyaniline they improve the catalytic activity of platinum towards the oxidation of hydrogen, product of the anaerobic microbial metabolism. Compared to polyaniline the fluorinated polymers are superior in the protection of platinum from becoming poisoned by metabolic by-products. The high stability of poly(2,3,5,6-tetrafluoroaniline) towards microbial and chemical degradation makes this compound a highly promising candidate for applications in microbially aggressive environments like sewage or sewage sludge. (C) 2004 Elsevier B.V. All rights reserved.