Nitrogen-Doped 3D Graphene-Supported Palladium Nanoparticles as Durable and High-Performance Electrocatalysts for Direct Alcohol Fuel Cells

The design and development of efficient, affordable, and durable electrocatalytic anode materials are crucial for realizing direct alcohol fuel cells (DAFCs) as reliable and environmentally friendly alternatives to conventional combustion-based energy technologies. Herein, we present an efficient and easily reproducible strategy for crafting nanosized palladium (Pd)-loaded nitrogen-doped three-dimensional reduced graphene oxide (Pd-3D-NrGO), envisaged as a prospective nanoelectrocatalyst for alcohol oxidation reactions (AORs). The detailed physicochemical characterization revealed that the synthesized Pd-3D-NrGO exhibits a uniform distribution of Pd nanoparticles, with an average size of 4.2 nm. The fabricated Pd-3D-NrGO composite demonstrated high electrocatalytic activity and long-term stability toward methanol and ethanol oxidation reactions (MOR and EOR). Comprehensive physicochemical and voltammetric studies establish that the uniquely conductive, porous architecture of Pd-3D-NrGO, featuring abundant and highly accessible electrocatalytic sites, provides a high electrochemically active surface area (ECSA) (205.9 m 2 g Pd –1 ), efficient mass transport, and enhanced metal utilization with substantial exposure of Pd (111) facets. The catalyst exhibits outstanding mass activities of 2235 and 3298 mA mg Pd –1 for MOR and EOR, respectively, which are almost 10 times more than those observed for conventional Pt/C and Pd/C catalysts currently employed for the design of DAFCs. The simplicity and scalability of the synthetic strategy, together with the excellent electrocatalytic performance of the Pd-3D-NrGO composites, make them promising anode materials for the development of practically viable DAFCs.