PROPERTIES OF MOLYBDOPHOSPHATE HETEROPOLYANIONS AND THEIR APPLICATION IN ELECTROCATALYSIS

Abstract

Polyoxometallates (POMs) are increasingly used as electrocatalysts for the determination of several types of species. Dawson and Keggin-type heteropoly anions are preferentially used in industry as catalysts. Properties of Dawson-type molybdophosphate heteropoly anions are discussed in the present review. Electrochemical behavior of Keggin- and Dawson-type molybdophosphate heteropoly anions has been reviewed. The oxidation-reduction potentials of electron reductions of the [P2Mo18O62]6– anion in solutions with various pH and in different media are cited. Special focus is made on methods of designing of electrodes modified by POMs. The most common deposition techniques of POMs include chemisorption, electrodeposition, encapsulation in polymers or sol–gels, and formation of hybrid POM–organic species. Advantages and disadvantages of various techniques are discussed. Modified electrodes are characterized by electrochemical stability, shifting of characteristic peaks and sensitivity to pH change.

Keywords

• molybdophosphate heteropoly anions
• electrocatalysis
• modified electrode