Kinetics and Mechanism of the Reduction of Enneamolybdonickelate(IV) by Oxalate

Heteropolyacids and their salts are known as acidic and redox catalysts in some reactions [1-3]. Studies of the kinetics and mechanism of redox reactions of heteropolyacids and their salts are instructive, given their value as redox reaction catalysts. Ammonium enneamolybdonickelate(IV) {(NH4)6[NiMo9O32]6H2O} is a Waugh-type heteropolyacid salt. It can oxidize a range of substances, including organic and inorganic reagents [4]. However, very few reports on the kinetics and mechanism of this type of heteropolyacid salts as oxidant have appeared. This paper reports the kinetics and mechanism of the reduction of enneamolybdonickelate(IV) by oxalate.