Nano-Au Catalysts Modified with TiO2: Enhancement of Electrocatalytic Activity for 1-Propanol Oxidation in Alkaline Media

Abstract

Electrocatalytic activity of the anode for alcohols oxidation is a critical issue in fuel cell which is considered as a clean energy. Performance deterioration of the catalyst takes place due to the adsorption of carbonaceous residues on the electrode surface, which is also known as poisoning of the electrode. Desorption of carbonaceous residues is thought to be an essential solution but not has been studied systematically. In this work, we investigate both the desorption of carbonaceous residues and the promotion of electrocatalytic activity to alcohols oxidation reactions by using Au nanoparticles (NPs)-TiO2/polyaniline (PANI) composite to boost the overall activity of electrocatalytic alcohol oxidation reactions. Desorption of carbonaceous residues and electrocatalytic activity of alcohol oxidation reactions are evaluated by cyclic voltammetry (CV) measurements in various alcohols. The chronoamperometric i-t curves are measured to evaluate the stability. Mechanisms for desorption of carbonaceous residues and enhancement of the electrocatalytic activity are elaborated and summarized. Electrodes with TiO2 decoration show better performance than TiO2-free specimens. In addition, Au NPs-decorated composites not only show an extra characteristic peak of alcohol oxidation reactions but also perform a constructive effect on the already existing oxidation reaction, indicating the promotion of electrocatalytic oxidation of alcohols. (C) 2019 The Electrochemical Society.