Investigation of different metallic cathodes towards electro-reductive desulfurization of thiophenic compounds
Volume Title: 1
1School of Chemical, Petroleum and Gas Engineering, Iran University of Science and Technology, Tehran, 16846-13114, Iran
2School of Chemical Engineering, Iran University of Science and Technology, Tehran, 16846-13114, Iran
The performance of different metallic cathodes was investigated towards desulfurization efficiency as well as the current efficiency of Thiophene and Benzothiophene. The electroreductive reactions were carried out in a divided electrochemical cell under the same constant current using chronopotentiometry method for 6 h. The solutions were prepared using 2000 mg L-1 of thiophenic compounds in a 0.5 M H2SO4 electrolyte. The cyclic voltammetry of electrodes was measured at 50 mV s-1 before each experiment which showed that 15 mA cm-2 and 25 mA cm-2 is adequate for the electro-reductive desulfurization of the thiophene and benzothiophene. The GC-MS analysis of initial and final samples revealed that electrodes having high H2 evolution overpotential are appropriate ones in terms of desulfurization and current efficiency simultaneously. Also, result demonstrated that the order of cathodes in terms of better desulfurization and current efficiency follows as Tin, Tungsten, Zinc, Molybdenum and Gold electrodes. The Tin electrode could achieve maximum desulfurization at the corresponding current efficiency either for thiophene or benzothiophene which were 92.81% at 20.36% for thiophene and 37.24 at 11.74%, respectively. The GC-MS analysis proved the direct desulfurization mechanism for all electrodes during experiments.