Helical PdPtAu nanowires bounded with high-index facets selectively switch the pathway of ethanol electrooxidation

Abstract

Intensive studies have been devoted to the preparation of electrocatalysts with outstanding activity and stability for ethanol oxidation. However, the electrocatalytic efficiency is far from satisfactory for application due to the low catalytic activity and C1 product selectivity. Herein, helical PdPtAu nanowires (NWs) surrounded by high-index facets are fabricated for ethanol electrooxidation with enhanced C1 selectivity. Among the PdPtAu NWs with different Au contents, Pd₁₄Pt₅Au₂ NWs show the highest specific activity, which is 1.4, 5.5, and 7.3 times that of Pd₁₄Pt₅ NWs, commercial Pt black, and Pd black, respectively. The Pd₁₄Pt₅Au₂ NWs have high anti-poisoning ability as confirmed by CO stripping and in situ FTIR spectra of CO adsorption. In situ FTIR investigations during the ethanol oxidation reveal that Pd₁₄Pt₅Au₂ NWs enhance the cleavage of the C–C bond, leading to a 3.3-fold increase in C1 selectivity (23.2%) compared with that of commercial Pd black (7.0%).