Gold-catalyzed construction of atomically rough surfaces towards high-efficiency ethanol electrooxidation.

Abstract

Atomic surface engineering for nanostructures significantly contributes to the enhancement of electrocatalysis for a given chemical reaction. However, exploring a facile method to elaborately regulate surfaces at atomic scale remains a grand challenge. Herein, we report the construction of atomically rough surfaces (ARSs) on Au-based binary alloys through a novel and controllable gold (Au)-catalyzed strategy, which involves the first synthesis of Au-based bimetallic nanoalloys, i.e., AuPd and AuAg, and subsequent reduction of another metal ions (Pt, Pd, or Ag) initiated by Au sites on the alloy particle surfaces. By combining ARSs with low-coordinated atoms with ligand effect induced by vicinal Au atoms, the as-prepared ARSs exhibit good activity and durability toward ethanol oxidation reaction (EOR) in an alkaline medium. In particular, the Pd-Pt ARSs on the AuPd alloy particle surface (denoted as AuPd-Pt) exhibit the highest electrocatalytic EOR performance in terms of both specific activity (14.9 mA cm^-2) and mass activity (28.5 A mg^-1), surpassing those of their AuPd alloy counterparts, commercial Pd/C catalyst, and most Pd-based electrocatalysts reported recently. In situ Fourier transform infrared (FTIR) spectroscopy reveals that the EOR process on the Pd-Pt ARSs strongly prefers incomplete oxidation, which is further authenticated by the density functional theory (DFT) calculations.