Microwave-assisted synthesis of graphene-supported PtFeCu nanoparticles for enhanced methanol oxidation in direct methanol fuel cells

Direct methanol fuel cells (DMFC) are one of the most promising alternative energy sources because of their simple construction, high energy density, and high energy conversion efficiency. Platinum (Pt) stands as a quintessential catalyst in fuel cell applications, yet its widespread adoption is impeded by high costs and susceptibility to carbon monoxide (CO) poisoning. To address these challenges, we developed a PtFeCu/RGO nano-catalyst with superior activity and stability. Leveraging additional metal components and employing an efficient, environmentally benign microwave-assisted synthesis technique alongside a cost-effective approach, we synthesized PtFeCu/RGO nanoparticles. These nanoparticles exhibited a narrow size distribution (average size: 3.53 ± 0.69 nm) and uniform dispersion on reduced graphene oxide, devoid of agglomeration. Electrochemical characterization revealed that the PtFe₂Cu/RGO catalyst achieved an electrochemically active surface area (ECSA) of 165.41 m2/g at a scan rate of 50 mV/s. It demonstrated a high mass activity for the methanol oxidation reaction (MOR), reaching 1452.71 mA/mgPt at 0.85 V vs. Ag/AgCl, and maintained a stable current density of 226.61 mA/cm2 during chronoamperometric testing. Additionally, the catalyst exhibited a low CO oxidation onset potential of 0.596 V, indicating enhanced CO tolerance. Oxygen reduction reaction (ORR) measurements using the rotating disk electrode (RDE) method confirmed the catalyst’s excellent ORR performance and durability. These results confirm the enhanced electrocatalytic properties and durability of PtFe₂Cu/rGO, attributable to the synergistic effect of alloying and the high conductivity of the rGO support. The use of a microwave-assisted green synthesis process reduces energy consumption and chemical waste, aligning with the principles of green chemistry. This work provides a cost-effective and sustainable solution for clean energy conversion and directly supports the United Nations Sustainable Development Goal 7 (Affordable and Clean Energy).