Efficient Ternary Synergism of Platinum/Tin Oxide/Nitrogen-Doped Carbon Leading to High-Performance Ethanol Oxidation

Abstract

Direct ethanol fuel cells are attractive alternative power sources due to the use of liquid fuels featuring high energy density, low toxicity, easy storage, and biomass-derived production. To date, most Pt-based electrocatalysts are still limited by low mass activity and high susceptibility to poisoning for the ethanol oxidation reaction (EOR) in acidic medium. Herein, we have constructed a ternary platinum/tin oxide/nitrogen-doped carbon electrocatalyst for the EOR by highly dispersing the hybridized platinum/tin oxide on nitrogen-doped carbon nanocages. CO electrooxidation from the stripping experiments is used as a sensitive indicator to evaluate the antipoisoning capability of the catalysts. By a comparison study on a series of designed catalysts, the correlation of the CO resistibility with the geometrical configuration has been well established for the catalysts. We demonstrate that the efficient ternary synergism of Pt/SnOx/N-doped sp2-C via the heterointerfaces is the key to high CO resistibility, which could facilitate the oxidative removal of CO species at Pt sites by the adsorbed OH species generated at neighboring SnOx sites and thereby the facile regeneration of Pt active sites. Accordingly, a synergistic catalyst has been optimized which shows high EOR performance in acidic medium with a mass activity of 1187 mA mgPt–1 and high durability, in comparison with most reported catalysts to date. This study provides an approach of exploring advanced EOR electrocatalysts for potential applications.