Effect of deposition potential and KOH concentration on ethanol oxidation reaction with Pd nanoparticles electrodeposited on glassy carbon from reline.

Pd nanoparticles (PdNPs) are deposited electrochemically on the glassy carbon electrode surface using PdCl 2 dissolved in a deep eutectic solvent composed of choline chloride and urea (reline). The morphology and particle size of the PdNPs are determined from SEM exhibiting a homogeneous distribution with potential deposition depending on particle size. The particles display a core-shell morphology, consisting of Pd(0) as the core and Pd(OH) 2 as the shell. The ethanol oxidation reaction, EOR, is evaluated at different KOH concentrations. The electrocatalyst with the highest mass activity is achieved at −750 mV potential deposition and 1 M KOH, exhibiting 3126 ± 606 mAmg Pd −1. However, when 0.1 M KOH is used the mass activity decreases to one-third the value obtained at 1 M KOH. Notwithstanding, the mass activity displayed by these PdNPs is superior to that reported for other Pd-based nanoparticles synthesized using more complex, time-consuming and costly methods reported in the literature. [Display omitted] • PdNPs were prepared by electrodeposition method using reline as DES. • The morphology of the electrodeposited PdNPs is core-shell Pd@Pd(OH) 2. • PdNPs electrodeposited at −750 mV was the best MA for EOR using 1 M KOH. • Different KOH concentrations were employed to evaluate the EOR. • The optimal concentration of KOH in the EOR was 1 M followed by 0.5 and 0.1 M. [ABSTRACT FROM AUTHOR]