Electrocatalytic reduction of H2O2 at P2Mo18O626- modified glassy carbon

Catalysis of the electroreduction of H2O2 by the polyoxometalate P2Mo18O626 - is described. The presence of polyoxometalate in solution leads to electr ocatalytic currents at potentials as positive as + 0.35 V versus Ag/AgCl. M odification of the surface of a glassy carbon electrode by adsorption of P2 Mo18O626- results in the formation of an anionic monolayer showing catalyti c redox activity at the same unusual potential. The currents of H2O2 electr oreduction can be greatly enhanced by coating the electrode with multiple l ayers of polyoxometalate and a charge balancing cation. A possible catalyti c mechanism is proposed. (C) 2000 Elsevier Science Ltd. All rights reserved .