Kinetic Modelling of the Fenton-Like Oxidation of Maleic Acid Using a Heterogeneous Modified Polyacrylonitrile (Pan) Catalyst

Abstract

A kinetic model has been developed that expresses the oxidation of maleic acid in solution using a novel modified (polyacrylonitrile) PAN catalyst/hydrogen peroxide system. The novel modified PAN catalyst contains immobilised Fe3+and its reaction with hydrogen peroxide is thought to generate reactive hydroxyl radicals according to Fenton's reaction as well as another active iron oxo species. The model takes into account the presence of both hydroxyl radicals and active iron oxo species as well as hydroperoxyl radical and hydrogen peroxide in the oxidation process. Kinetic constants for the modified PAN/H2O2 system towards the decomposition of maleic acid were determined, and their sensitivity analysed. Predicted concentration profiles of the radical species (‘OH, HO2 O'2.-), as well as iron species (Fe(III), Fe(II) and FeO) helped in gaining a better understanding the oxidation process. This model, with the new set of kinetic parameters, provides a superior fit to the experimental data compared to kinetic constants from the literature.