Octahedral and tetrahedral cobalt species in nanodimensional pores of mordenite zeolite as modified carbon paste electrode for determination of ascorbic acid

A new method is developed for the catalytic oxidation of ascorbic acid (AA) at zeolite-modified carbon paste electrode, doped with cobalt (II) (Co2+ MOR/ZME). Characterisation of Co2+-loaded mordenite zeolite has been carried out by diffuse reflectance spectroscopy (DRS), Fourier transform-infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). FTIR and DRS show octahedral and tetrahedral Co2+ species into mordenite channels. TEM pictures reveal the formation of cobalt phyllosilicate. Cobalt (II) exchanged in zeolite-type mordenite acts as a catalyst to oxidise AA. The modified electrode lowered the overpotential of the reaction by similar to 500 mV. The mechanism of electrochemical oxidation of AA using modified electrode was investigated by cyclic voltammetry (CV) study. Results of CV using this modified electrode show one well-resolved anodic wave for the oxidation of AA, which makes it possible for determination of compound.