An assessment of newly developed urea fuel cell electrodes

This research developed more efficient Direct Urea-Hydrogen Peroxide Fuel Cell (DUHPFC) utilizing an H-type electrochemical cell methodology, offering a regulated setting to assess a unique nickel zinc iron oxide coated stainless-steel anode, and examines their electrochemical performance. The cell underwent systematic testing at several KOH concentrations (1 M, 5 M, and 9 M) at 25 °C, as well as at various temperatures (25 °C, 35 °C, 45 °C, 55 °C, and 65 °C) using 9 M KOH, with a catholyte of 2 M H 2 SO 4 and 2 M H 2 O 2 . The electrochemical methods, such as open circuit potential (OCP), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS), were utilized to examine cell voltage, current density, power density, and impedance properties. The highest open circuit voltage (OCV) of 0.86 V was recorded at 65 °C using 9 M KOH, reflecting improved electrochemical potential at elevated temperature. The research findings indicated that KOH concentration markedly influences performance, with 9 M KOH at 25 °C producing the peak power density of 63.50 mW/cm 2 at 24.23 mA/cm 2 , whereas diminished concentrations displayed decreased electrochemical activity. Likewise, an increase in temperature enhanced reaction kinetics, with 65 °C yielding the peak power density of 88.2 mW/cm 2 at 27.4 mA/cm 2 . Electrochemical impedance spectroscopy (EIS) revealed a low transfer resistance of 8 Ω, indicating efficient electron transfer at the anode-electrolyte interface. The efficiency studies performed here revealed that energy and exergy efficiencies improved with temperature, attaining 30.7 % and 29.5 %, respectively, at 65 °C. The method proves effective for electrode screening and performance assessment, offering key insights for optimizing catalysts and advancing urea-based fuel cells for sustainable energy applications. • H-type cells are used to assess newly developed direct urea fuel cell electrodes. • NiZnFe 2 O 4 anode boosts catalytic activity and urea oxidation performance. • 9 M KOH gives a peak power density of 63.50 mW/cm 2 in optimization study. • Increased temperature improves kinetics with an efficiency of 30.7 % at 65 °C.