In this investigation, the catalytic activity of palladium nanoparticles (PdNPs)-modified glassy carbon (GC) (simply noted as PdNPs/GC) electrodes towards the formic acid electro-oxidation (FAO) was investigated. The deposition of PdNPs on the GC substrate was carried out by a potentiostatic technique at different potentials and the corresponding influence on the particles size and crystal structure of PdNPs as well as the catalytic activity towards FAO was studied. Scanning electron microscopy (SEM) demonstrated the deposition of PdNPs in spherical shapes and the average particle size of PdNPs deposited at a potential of 0 V vs. Ag/AgCl/KCl(sat.) was the smallest (ca. 8 nm) in comparison to other cases, where the deposition proceeded at higher potentials. The electrochemical measurements agreed consistently with this, where the highest surface area of PdNPs was calculated similarly for the deposition carried out at 0 V vs. Ag/AgCl/KCl(sat.). Interestingly, the X-ray diffraction (XRD) analysis revealed a similar dependency of the PdNPs crystal structure on their particle size and distribution. The deposition of PdNPs at 0 V vs. Ag/AgCl/KCl(sat.) seemed exhibiting the best crystallinity. From the electrocatalytic point of view, the activity of the PdNPs/GC electrode towards FAO decreased with the deposition potential of PdNPs, which influenced consequently the particle size, shape, and/or crystallographic orientation of PdNPs.
Al-Akraa, Islam M. Dr.; Mohammad, Ahmad M. Prof; El-Deab, Mohamed S. Prof; and El-Anadouli, Bahgat E. Prof, "On the Catalytic Activity of Palladium Nanoparticles-Based Anodes Towards Formic Acid Electro-oxidation: Effect of Electrodeposition Potential" (2015). Chemical Engineering. 27.