The ethanol oxidation reaction on bimetallic PdxAg1-x nanosheets in alkaline media and their mechanism study

Abstract The direct ethanol fuel cells (DEFCs) are considered as a kind of green and sustainable portable power source with high energy density, stable convert efficiency and zero/low emissions. In this study, the PdxAg1-x nanosheet assemblies (NSAs) composed of a 2D sheet structure are synthesized by a facile one-step method. Alloyed PdxAg1-x NSAs perform better catalytic activities and anti-toxicity than that of pure Pd NSA, closely related to their macroscopic morphological characteristics and microscopic electronic structure. Also, the mechanisms of the common four electrons pathway of ethanol oxidation reaction (EOR) on PdxAg1-x NSAs are studied using the cyclic voltammetry method. Higher catalytic temperature and concentrations of both the KOH and ethanol have a positive effect on the overall reaction of the EOR, especially for the rate determination step in anodic scanning and the removal of the oxygen containing Pd-related intermediate species during cathodic scanning. However, excessive concentrations of KOH and ethanol should be avoided due to the formation of the oxide layer embedded at the surface of Pd at higher potentials and the decrease in conductivity, respectively. So, appropriate reaction temperature and medium conditions are favorable for the catalytic reaction.