MEDIATED ELECTROCHEMICAL OXIDATION OF PHENOL BY Co(III) AS MEDIATROR

• Main Author: Saiya, Abdon
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/35387
• Institution: Institut Teknologi Bandung

Mediated electrochemical oxidation (MEO) is one of the method for oxidation of organic compounds by using a mediator. Currently, MEO has been developed for destruction organic pollutants because they have several advantages, namely the process take place at a relatively low temperature, exhausted gas does not contain toxic elements, and do not generate secondary waste. Co(III) is known as a strong oxidant that is either used as mediator, but the spesies of Co(III) in aqueous mediaum very quickly reduced to Co(II) due to the oxidation of water. Therefore, this research studied the method of preparation solution of Co(III) was then used to oxidize phenol. Mediator Co(III) has been prepared by oxidizing Co(II) in an electrochemical cell consisting of two compartments, namely the anode and cathode compartments using Pt electrodes, respectively and was separated by a silica membrane. The concentration of Co(III) formed during oxidation determined by potentiometric titration, where the Co(III) aliquot was added into Fe(II) excess solution and the remaining of Fe(II) which did not react has been titrated with Ce(IV). Important parameters studied include the standard oxidation potential of mediators, acid concentration, and temperature. From the research result obtained that the concentration of Co(III) formed increases with increasing of potential and the concentration of nitric acid, and decreases with increasing temperature. At remains potential 6 V, temperature of 25oC and the concentration of nitric acid 4 M and the presence of 0,1 M AgNO3 in catholyte, 37% of Co(II) was converted to Co(III) for 2 hours. Co(III) formed is then used to oxidize phenol. In optimum conditions of preparation Co(III), 69,33% of phenol was oxidized into CO2.