Co3+ homogeneous mediator generation efficiency in a divided tubular electrochemical reactor with MFI-type zeolite membrane

In the present work a tubular electrochemical cell with MFI-type zeolite coated membrane (TZM) was engineered and evaluated using Co2+ oxidation efficiency in high acid medium. Electrolysis of Co2+ was carried out at room temperature (20 +/- 3 C-omicron) in 4M H2SO4 at anodic half-cell, and showed 42% Co2+ oxidation with 0.3 V higher cell voltage than the commonly used Nafion324 membrane in planar arrangement. Further, the TZM membrane was robust when operated in the cell at different temperatures (10, 30 and 50 C-omicron) as no noticeable change in surface morphology was observable by SEM analysis. Further testing showed Co2+ oxidation efficiency decreased with temperature and increased with current density, suggesting stable operation of the TZM but structural change in cobalt precursor. The TZM membrane showed less resistance 0.91 Omega cm(2) (at 10 C-omicron) than Nafion324, which is decreased with increasing temperature from 10 C-omicron to 50 C-omicron. A 72 h test of the TZM at slightly elevated current density (70 mA cm(2)) showed increased oxidation efficiency of Co2+ to 57% compared to the traditional planar cell with Nafion324 (43%). Therefore, the engineered tubular electrochemical reactor with TZM is robust for generation of homogeneous mediators towards environmental pollution removal. (C) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.