A novel nanoporous palladium catalyst for formaldehyde electro-oxidation in alkaline media

In this work palladium nanoparticles (nanoPd) were successfully fabricated using a hydrothermal method from the solution of PdCl2 + EDTA + HCHO. SEM image of the nanoPd exhibits a novel three-dimensional porous texture, presenting high stability and significantly large real surface area. Electrocatalytic activity of the nanoPd towards formaldehyde oxidation in alkaline media was evaluated by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). Electrooxidation of formaldehyde on the nanoPd electrode takes place at a low onset potential of ca. -0.85 V (vs SCE) and large anodic current densities. Chronoamperometric data of the nanoPd electrode shows high and stable anodic currents for formaldehyde oxidation. It was also observed that the steady-state current density shows a well linear increment with formaldehyde concentration in the range of 0 to 20 mM formaldehyde. EIS investigation at different formaldehyde concentrations presents very low values of charge transfer resistances for formaldehyde oxidation on the nanoPd. Results show that prepared nanoPd electrode is a highly efficient catalyst for formaldehyde oxidation in alkaline media.