A heterogeneous double chamber electro-Fenton with high production of H2O2 using La–CeO2 modified graphite felt as cathode

Abstract

Hydrogen peroxide synthesis by electro-reduction of O 2 to substitute the current anthraquinone process has attracted a great deal of attention. Low oxygen utilization rate and low hydrogen peroxide production remain obstacles to electro-Fenton application. In situ H 2 O 2 generated by electrochemical reaction depends on the electrochemical performance of the cathode and the structure of the reactor. Here, novel graphite felt (GF) modified by La-doped CeO 2 (La–CeO 2 ) was developed as a cathode. A new double chamber electro-Fenton reactor was proposed, where an organic ultrafiltration membrane was used to prevent H 2 O 2 from spreading to the anode. The effects of hydrothermal temperature, time and urea concentration on the electrochemical properties of graphite felt were investigated. The accumulated concentration of H 2 O 2 on the modified cathode reached 218.4 mg·L –1 in 1 h when the optimal conditions of hydrothermal temperature 120 °C and urea concentration 0.55% (mass) in 24 h. The degradation rate of methyl orange reached 98.29%. The new electro-Fenton reactor can efficiently produce hydrogen peroxide to degrade various organic substances and has a high potential for treating wastewater in the chemical industry.