Electrochemical Hydrogenation and Desulfurization of Thiophenic Compounds Over Mos2 Electrocatalyst Using Different Membrane-Electrode Assembly

The desulfurization-hydrogenation of thiophene and benzothiophene in hexadecane as a model diesel fuel was studied through a divided cell with the incorporation of a membrane electrode assembly (mea) under different current density at a constant charge. the reduction of the thiophenic compounds was investigated using a prepared mos2 nano-electrocatalyst, nafion (commercial proton exchange membrane), and synthesized sulfonated poly ether ether ketone (speek). field emission scanning electron microscopy (fesem) and x-ray diffraction (xrd) were used to characterize the mos2 electrocatalyst, which confirmed the formation of 23-25 nm ball-like nano-threads of mos2. also, the electrocatalyst and/or mea was electrochemically analyzed by cyclic voltammetry (cv), linear sweep voltammetry (lsv), and electrochemical impedance spectroscopy (eis). the gas chromatography-mass spectroscopy (gc-ms) analysis of the reactants and products revealed the direct desulfurization on the thiophene reduction process and the desulfurization along with the desulfurization pathway on the benzothiophene reduction experiment. a maximum desulfurization efficiency of 79.6% at 20 ma cm-2 and 51.5% at 30 ma cm-2 under the constant charge of 300 c was obtained for thiophene using the mos2-nafion and mos2-speek system, respectively. moreover, a maximum hydrogenation and desulfurization efficiency of 28% and 59.1% occurred at 50 ma cm^-2 and 70 ma cm^-2, respectively, for the benzohiophene-nafion system under the constant charge of 400 c. the distribution of the products affirmed that the desulfurization reaction contributed more at a higher current density against the hydrogenation process at a lower current density.