<p>For the first time, this study investigated the behaviors of CuO and FeO metal oxides synthesized from bean shell extract using an environmentally friendly green synthesis method at varying cell temperatures in PEMFCs according to the amount of Pt used. Analyzed techniques such as XRD, SEM–EDX, TEM, and XPS were used to ascertain the structural and morphological characteristics of the produced catalysts. The performance of the catalysts was evaluated based on the voltage-current density values obtained from PEMFCs at different cell temperatures and increased at higher cell temperatures.At a cell temperature of 70 °C, the Pt-FeO/C and Pt-CuO/C catalysts exhibited higher power values than the Pt/FeO-C and Pt/CuO-C catalysts, containing only half the amount per unit area. The power density values for catalysts were tested as follows: 3380 mW/cm²mg_Pt for Pt-FeO/C, 1697 mW/cm²mg_Pt for Pt-CuO/C, 919 mW/cm²mg_Pt for Pt/FeO-C, and 1264 mW/cm²mg_Pt for Pt/CuO-C, and these values were determined to be higher than the values measured using the Pt/C (431 mW/cm²mg_Pt) catalyst. According to the measured current density-power density values, It was determined that the performances of the catalysts were Pt/FeO-C &gt; Pt-CuO/C &gt; Pt/CuO-C &gt; Pt-FeO/C.</p>