3rd International Conference on Basic Sciences and Technology (ICBAST) , Antalya, Türkiye, 16 - 19 Kasım 2023, cilt.25, ss.120-133
This research, conductive polymer supported modified electrode system which was prepared for
usage in direct methanol fuel cells. To test the behavior of these electrode system for methanol oxidation, cyclic
voltammetry (CV), chronoamperometry (CHR) and electrochemical impedance spectroscopy (EIS) methods
were used as electrochemical methods. As the working electrode, pencil graphite electrode (PGE) was preferred
because of its porous structure, good ion conductivity, practicality in application and ease of preparation and
obtaining. Thiophene derivative 4,4')-2,2'-(diazen-1,2 diylbis(4,1 phenylene))bis(4 (thiophene-2-ylmethylene)
oxazol-5(4H)-one), (DiAzBiPhBiTyOx) monomer was prepared and electrochemically polymerized by CV
method in 0.01M TBAP and 0.05 HClO4 containing ACN solution on the surfaces of PGE. The spectroscopic
characterization of the synthesized monomer was performed by NMR spectroscopy. Optimum polymerization
conditions of monomer was determined according to scanning rate, potential range and acid density. The
obtained modified electrode system (PGE/PDiAzBiPhBiTyOx) was doped with chloroplatinic acid hexahydratPt2Cl6.6H2O (Pt) at different densities and the optimum catalyst density was determined as 3.25mM
(PGE/3.25mMPt@PDiAzBiPhBiTyOx). The methanol oxidation performances of conductive polymer film,
platinum and conductive polymer supported platinum catalyst systems were investigated separately. While the
methanol oxidation responses of the conductive polymer film and platinum are almost similar, the methanol
oxidation response of the platinum doped conductive polymer film catalyst system is higher. The modified
electrode characterization was performed by CV, CHR and EIS methods. Furtheremore obtained modified
electrode systems were characterized by FESEM/EDS, XRD to confirm the structures and morphologies. Also,
the theoretical values such as electrochemical surface area (ECSA) and specific capacitance (Cs) were
calculated in aqueous acidic solution with and without methanol. Cs values of the
PGE/3.25mMPt@PDiAzBiPhBiTyOx electrode in aqueous acidic solution with and without methanol were
3.861 and 3x10-4Fg-1
respectively. Also, the electrochemical surface area values of the same electrode in
aqueous acidic solution with and without methanol were 196.437 and 21.150m2g-1
respectively.