Synergistic Effect of Electrogenerated Hydrophilic Carbon Supports on the Preparation of Nanogram-Scale Loading Pd Electrocatalysts

challenge for sustainable electrochemical technologies. This work reports a disruptive one-pot synthesis strategy for the preparation of Pd-based nanocomposites at the nanogram-scale, utilizing the tunable redox properties of electrogenerated hydrophilic carbons (EHC). We demonstrate that EHC generated in tartaric buffer (EHC@T) acts as a multi-functional platform, serving simultaneously as a conductive support and reducing agent. Crucially, the integration of a second component, EHC generated in phosphate buffer (EHC@P), provides an architectural synergy: beyond its oxygen-storing capacity, EHC@P is shown to be indispensable for the chemical and electrochemical stabilization of the ultralow Pd loadings The resulting Pd–EHC@T,P nanocomposite was tested for the oxygen reduction reaction (ORR) activity, showing a unique 'oxygen-memory' effect: the persistence of significant reduction current even in deoxygenated media. These findings open a new pathway for developing cost-effective, sustainable nanocatalysts and enables the design of electrochemical applications previously considered unfeasible.