Linkage of oxidized phosphorus groups in graphene alongside surface-clean control of Pd nanocrystals attain enhanced ethanol oxidation

The combination of electronic state engineering and surface-clean control represents a viable strategy for developing advanced electrocatalysts toward the ethanol oxidation reaction (EOR). Herein, the phosphorus-containing functional groups (oxidized P species) modified reduced graphene oxide (PG) with three dimensional (3D) hierarchical macrostructures was synthesized by a common hydrothermal method, and ultrafine surface-clean Pd NCs were equably anchored on PG through a facile hydrogen balloon reduction strategy in the absence of surfactants or organic solvents (Pd/PG). In the alkaline EOR, Pd/PG delivers significantly enhanced catalytic activity (with a mass activity of 2302.0 mA mg −1 ) alongside remarkable long-term operational durability and stability, distinctly surpassing both Pd/G and commercial Pd/C. Combined characterization and experimental study attest the enhanced electrocatalytic behavior of Pd/PG is derived from the linkage of oxidized P species and surface-clean control. Surface-clean Pd NCs and 3D hierarchical macrostructures affords a free exchange of reactants/products and dramatically facilitate mass/electron transfer during EOR. The linkage of oxidized P species makes electron transfer from PG to Pd and generates an increased electron density at Pd sites, leading to a reduced energy barrier for CO ads oxidation and enhanced OH ads adsorption, thereby collectively promoting the catalytic activity and long-term operational durability. Meanwhile, interfacial electron transfer fosters a stronger Pd-support interaction, thereby suppressing agglomeration, dissolution, and Ostwald ripening during the EOR process and ultimately bolstering the long-term durability of the catalyst. This study establishes that synergistic surface-clean and interfacial engineering enhances electrocatalysis, informing the development of advanced carbon-supported electrocatalytic materials.