Doğrudan alkollü yakıt pilleri için yenilikçi katalizör sentezi

In this thesis work, non-precious nitrogen-doped iron-nickel and iron nanoparticles, supported on three-dimensional reduced graphene oxide, are prepared via a combination of sacrificial support method and wet impregnation method as alternative anode catalysts to precious metal catalysts of the direct methanol fuel cells for electro-oxidation of methanol. Graphene oxide was synthesized via an improved Hummers method. Nitrogen doping was carried out by the pyrolysis of urea, which also provided the reduction of graphene oxide support simultaneously. Electrocatalytic activities of the catalysts for methanol electro-oxidation in acidic media were obtained by cyclic voltammetry (CV). Morphologies of the synthesized materials were obtained using scanning electron microscopy (SEM). The presence and distribution properties of the nanosized iron and nickel particles were detected via scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). Quantitative analyses of iron and nickel were conducted by inductively coupled plasma-optical emission spectrometry (ICP-OES). X-ray photoelectron spectroscopy (XPS) analyses were executed to obtain the surface chemical composition and bonding of the synthesized materials and to prove the formation of the alloy. Crystal structures of the materials produced were determined by examining their X-ray diffraction (XRD) patterns. Thermogravimetric analyses (TGA) of the samples were done under a nitrogen atmosphere to obtain their thermal behaviors.