Applications of metal oxide catalysts produced by the green synthesis method in PEM fuel cells

PEM fuel cells are the most powerful alternative to alleviate the problem of environmentally friendly power sources and eliminate the sustainability problem of other renewable energy sources. Commercialization of PEM fuel cell technology has been largely hindered by the high cost of Pt-based catalysts. To overcome these obstacles, it is possible to reduce Pt loading by using low-cost, electrically conductive metal-support interactive supporting materials and to use durable active catalysts. In this thesis study, FeO, Cu and Zr doped FeO nanoparticles in different percentages (1%, 5% and 10%) were synthesized using fig leaf extract with the green synthesis method. The synthesized nanoparticles were doped with platinum and activated carbon using the chemical reduction method and produced Pt-FeO/C, Pt-CuFeO/C, Pt-Cu5FeO/C, Pt-Cu10FeO/C, Pt-ZrFeO/C, Pt-Zr5FeO/C and Pt. -Zr10FeO/C catalysts were synthesized. The synthesized catalysts were used separately as anode and cathode electrocatalysts in the single-cell PEM fuel cell. The synthesized catalysts were studied at different cell temperatures (40, 50, 60 and 70 ºC) in PEM fuel cell cell applications and the cell temperatures at which the best activity was measured were determined. The gas flow rates given to feed the fuel cell were adjusted to 40 mL/min for oxygen and 20 mL/min for hydrogen to achieve 100% cell humidification. The activity and efficiency of the fuel cell cell were examined with the current density-voltage-power density polarization curves created at different temperatures. The power densities of the synthesized catalysts when used as cathode electrocatalysts at 70 ºC cell temperature range from PtCu5FeO/C > PtZrFeO/C> PtFeO/C> Pt/C, and when used as anode electrocatalysts at the same temperature, PtZrFeO/C> PtCu5FeO/C> PtFeO/C> Pt/ C was seen. PtCu5FeO/C catalyst showed very good activity as the cathode electrocatalyst and PtZrFeO/C catalyst as the anode electrocatalyst. Electrochemical CV measurements, morphological structures and physical properties of the synthesized catalysts were also evaluated by FTIR, SEM-EDX, BET and XRD analyses.