Kinetic study of an immobilized iron oxide for catalytic degradation of azo dye reactive black B with catalytic decomposition of hydrogen peroxide

A new immobilized iron oxide (SiG2) was used for the catalytic decomposition of H2O2 and further oxidation of azo dye reactive black B (RBB). The effect of temperature on the catalysis was studied. The decomposition of H2O2 followed pseudo first-order kinetics in the presence of SiG2. The rate constants and activation energy (∼60 kJ mol−1) of H2O2 decomposition were calculated from the experimental data. The combination of H2O2 and SiG2 were found to be efficient for the degradation of RBB. A two-stage reaction rate law (initiation stage and radical reaction stage) was proposed to simulate the degradation of RBB. The activation energy for RBB degradation at initiation and at radical reaction periods were 20.8 and 83.7 kJ mol−1, respectively.