|
Abstract
|
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 nanoelectrocatalyst, 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
|