Synthesis and electrocatalytic properties of polypyrrole doped by phosphonolybdic acid anions

Summary form only given. New routes to obtain Keggin structure phosphomolybdic heteropolyacid aniones doped polypyrrole were elaborated, and its spectral and electrochemical characteristics investigated. Pyrrole was found to be oxidized by non-aqueous phosphomolybdenic acid and its salts in CH/sub 3/CN, that cause polymerization. As was revealed, phosphomolybdic heteropoly acid anions are capable of catalysing pyrrole electrochemical polymerization. The chemicaly and electrochemicaly produced polypyrrole was shown to be doped by heteropolyanions of the structure H/sub (3+k)=n/Pmo/sub 12/O/sub 40´/ where (0< k< 6), (0< n< 3). The charge-discharge characteristics of the resulting material were studied by CVA and chroncamperometry techniques. The results evidence involvement heteropolyanions dopants in the redox conversions of the material. The electrochemical oxidation of a variety of organic substrates (naphtalene, antracene, tetramethylhydroquinone, hydroquinone, 2,6-ditertbutylphenol, tri-p-tolylamine, benzylalcohol etc.) on a platinum electrode coated with a heteropoly anions doped polypyrrole was studied. The electrocatalytic effect of anodic tetra methylhydroquinone, hydroquinone and tri-p-tolylamine oxidation on such electrodes was revealed. This makes it possible to effect oxidation of the above compounds on an electrode covered with heteropolyanions doped polypyrrole at lower potentials and a higher current density compered to perchlorate-anions doped polypyrrole electrode and an unmodified Pt electrode. The effect found is ascribed to the electrocatalytic action of heteropolyacid anions in the course of anodic oxidation.