Hydrogen Spillover Effect of High-Curvature Fullerene Boosts Efficient Ethanol Electrooxidation Over Palladium Catalyst

Abstract

Hydrogen spillover, involving the migration of hydrogen species produced by ethanol oxidation from metal nanoparticles to support materials, is conductive to develop advanced electrocatalysts applicable to ethanol oxidation reaction (EOR) and further overcome the performance limitations. Herein, the ethylenediamine-modified C60 (AC60) embedded in nitrogen-doped graphene aerogel (NG) anchoring Pd nanocrystals (Pd/AC60@NG) was synthesized as an electrocatalyst for EOR. The high curvature of C60 with the partial localization of p electrons and the increase of sp3 characteristics is of great significance for enhancing the interaction with hydrogen species and accelerating the migration of hydrogen species from the Pd surface to the C60 surface. Due to highly delocalized π-sphere surface, excellent electron nucleophilicity and minimal reorganization energy requirements, C60 can generate powerful electron and space confinement effects to hasten electron transfer and mitigate Ostwald ripening process. The intense interaction is established between C60 and NG through strong hydrogen bonds after C60 is modified by ethylenediamine, which enhances the stability and dispersibility of C60. The prepared Pd/AC60@NG exhibited significantly improved electrocatalytic activity compared to commercial Pd/C. This study opens new possibilities for designing and developing new carbon-based materials aimed at enhancing catalytic activity for ethanol oxidation, hydrogen evolution, and the oxygen reduction reaction.

Keywords: Hydrogen spillover, AC60, Nitrogen-doped graphene aerogels, Pd nanocrystals, Ethanol oxidation reaction