Enhanced electro-oxidation/peroxone (in situ) process with a Ti-based nickel-antimony doped tin oxide anode for phenol degradation

Abstract

Recently, a novel proof-of-concept oxygen reduction reaction (ORR) based electro-oxidation (EO) process has been developed, which was accomplished by integrating anodic electrochemical oxidation coupled with an in situ electro-peroxone process, by harnessing the anodic by-product O3 reacted with ORR cathode generated H2O2. To further enhance EO coupled in situ electro-peroxone, a nickel and antimony doped tin oxide anodic catalyst layer, namely NATO, was fabricated on Ti mesh to improve anodic oxidation and reinforce the generation of O3, thus promoting in situ Electro-peroxone. As a result, O3 generation rate was enhanced by 12.6%. Complete phenol, as a model organic compound, and 95% of TOC removal were achieved, respectively, during ORR-EO. Through kinetics and instrument analysis, results show that the amount of intermediates accumulated during phenol degradation was much less in this Ti/NATO based ORR-EO system than in a traditional EO system. Moreover, 35.7% of the energy consumption was saved for ORR-EO, owing to its reduced applied voltage and the enhanced in situ electro-peroxone process.