Nitrogen-Functionalized Carbon Surface Boosts Oxygen Reduction Electrocatalysis on a Pt Surface

Carbon supports serve as an essential framework for ensuring electrical connectivity while enabling the uniform dispersion and stabilization of nanocatalysts in electrochemical energy conversion devices. Beyond their roles in mechanical stabilization and electrical conduction, however, recent studies have shown that heteroatom incorporation (e.g., via doping or surface functionalization) on the carbon surface profoundly tailors catalyst−support interfacial properties, which leads to improved physical anchoring or modulated electronic structure of active sites. However, fundamental understanding of the catalytic promotion by such a heteroatom-introduced carbon surface has remained elusive because of a limited systematic approach on model catalysts and in-depth analyses. Herein, we designed Pt-based model catalysts using a nitrogen-functionalized carbon support, prepared via controlled urea annealing. Using comprehensive characterizations of X-ray and nuclear magnetic resonance spectroscopies, we identified the presence of Lewis-acidic nitrogen species stabilized by the extended π-conjugation network of the carbon matrix. Pt nanoparticles deposited on the nitrogen-functionalized carbon surface reveal a systematic down-shift in d -band energy level, which is associated with distinct electronic coupling between Pt sites and nitrogen group. Oxygen reduction reaction, as a model electrocatalysis, showed enhanced activity with increasing nitrogen modification of the carbon support, consistent with electronic structure modulation of the Pt sites. Moreover, the nitrogen functionalization enhances catalyst durability through increased nanoparticle anchoring and suppressing carbon corrosion. This study underscores the crucial role of interfacial electronic structure between support material and active material as another key descriptor to steer catalytic performance and durability.