Effect of Cobalt Substitution on Catalytic Activity of Fe3-XCoxO4 Catalyst

Abstract

Combination of Fenton-like reaction with heterogeneous catalyst has been recognized as effective way in removing persistence organic pollutants. Fe3-xCoxO4 catalyst has been considered as potential heterogeneous Fenton-like catalyst by substituting cobalt into the magnetite structure. In this study, details investigation on the effect of cobalt substitution in relation with catalytic performance of resultant catalyst was performed. The Fe3-xCoxO4 catalysts were synthesized through oxidation-precipitation method. The cobalt loading were varied at cobalt substitution value (x) of 0, 0.1, 0.2, 0.4 and 0.6, respectively. Interestingly,Fe3-xCoxO4 catalyst with x value of 0.4 has shown enhanced catalytic performance closed to 31% removal. The presence of cobalt led to the increased in catalytic activity by 17% as well as significant shift in the isoelectric point compared to the pristine catalyst (x=0). Moreover, the isoelectric point for Fe3-xCoxO4 at x=0 and x=0.4 were 5.00 and 8.44. This can be well described by the changes on resultant catalyst’s surface properties that led to enhance adsorption of AO7 molecules onto catalyst surface. The adsorbed AO7 molecules within the immediate vicinity of active sites were degraded rapidly by the generated interfacial hydroxyl radicals (•OH). Hence, such findings suggested that the substitution of cobalt provide positive influence in enhancing the redox activity of the resultant catalyst during the Fenton-like reaction