Tailoring the Electronic Structure of Nanoelectrocatalysts Induced by a Surface-Capping Organic Molecule for the Oxygen Reduction Reaction

Capping organic molecules, including oleylamine, strongly adsorbed onto Pt nanoparticles during preparation steps are considered undesirable species for the oxygen reduction reaction due to decreasing electrochemical active sites. However, we found that a small amount of oleylamine modified platinum nanoparticles showed significant enhancement of the electrochemical activity of the oxygen reduction reaction, even with the loss of the electrochemically active surface area. The enhancement was correlated with the downshift of the frontier d-band structure of platinum and the retardation of competitively adsorbed species. These results suggest that a capping organic molecule modified electrode can be a strategy to design an advanced electrocatalyst by modification of electronic structures.