Curvature-Induced Metal–Support Interaction of an Islands-by-Islands Composite of Platinum Catalyst and Carbon Nano-onion for Durable Oxygen Reduction

Geometry of carbon supports significantly affected electrochemical durability of Pt/C (platinum electrocatalyst supported by carbon) for oxygen reduction reaction (ORR). Carbon nano-onion (CNO) was used as the support, which is characterized by its nanosize (similar to Pt size) and high curvature. Superior ORR durability was guaranteed by Pt/CNO due to (1) its islands-by-islands configuration to isolate each Pt nanoparticle from its neighbors by CNO particles; (2) highly tortuous void structure of the configuration to suppress Ostwald ripening; and (3) the curvature-induced strong interaction between CNO and Pt. The finding that highly curved carbon surface encourages electron donation to catalysts was first reported.