Insights on the ethanol oxidation reaction at electrodeposited PdNi catalysts under conditions of increased mass transport

The development of high-performance electrocatalysts for alcohol oxidation is still a major challenge to use these reactions for sustainable energy applications such as hydrogen production. In addition, understanding the reactivity under different hydrodynamic conditions is essential since the fuel is continuously fed to the anode in practical applications. In this work, the synthesis, characterization and electroactivity of bimetallic PdNi nanocoatings generated by electrodeposition toward the ethanol oxidation reaction (EOR) is described. A catalyst formed by Pd0.91Ni0.09 nanoflowers showed the highest EOR activity and enhanced performance under moderate mass transport rate. Both OH- concentration and hydrodynamics affected the EOR activity and the product selectivity. Acetic acid was the main EOR product, but acetaldehyde formation increased when OH- was limiting or under faster mass transport rates. This study provides novel knowledge to understand the EOR on PdNi catalysts and exposes the importance of evaluating hydrodynamic conditions when developing new electrocatalysts. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.