Synergistic Impact of Graphitic Carbon Nitride Supported Pd–Cu Bimetallic Nanoparticles for Direct Ethanol and Methanol Fuel Cell Applications

Direct ethanol fuel cells (DEFCs) hold significant promise as sustainable energy conversion devices, yet the slow kinetics of ethanol (EtOH) oxidation remain a critical challenge. In this study, we present a novel catalyst comprising palladium-copper (Pd-Cu) bimetallic nanoparticles (NPs) based on graphitic carbon nitride (gC₃N₄) as an effective anode catalyst toward EtOH and methanol (MeOH) electrooxidation. The Pd-Cu/gC₃N₄ catalyst was synthesized via a facile and scalable technique, showing high catalytic performance and stability toward EtOH and MeOH electrooxidation. The enhanced efficiency is due to the gC₃N₄ support, which provides uniform dispersion and effective charge transfer; the Cu shows a bifunctional effect, which supplies oxygenated species to eliminate intermediates. The electronic interaction between Pd and Cu enhances the ethanol oxidation kinetics. Synergistic effects can explain the improved catalytic behavior. Electrochemical characterization, including cyclic voltammetry and chronoamperometry, demonstrated the superior performance of the Pd-Cu/gC₃N₄ catalyst compared to conventional catalysts (such as Pt/C or Pd/C etc.), ascribed to the synergetic consequence among Pd and Cu NPs and the superior catalytic activity and unique electronic property of gC₃N₄ support. To examine the proposed material's unique properties and superior catalytic performance, its performance was compared with gC₃N₄, used as a reference material. The Pd-Cu/gC₃N₄ shows better current density (CD) values with higher forward current peak maxima for 1 M EtOH (4.54 mA/cm²) and 1 M MeOH (22.16 mA/cm²) in the presence of 0.5 M KOH at a 50 mV/s scan rate. Overall, the proposed materials show better electrochemical performance in fuel cell applications.