Electrochemical synthesis of dendritic Pd-CoO/PW10V2/rGO and its electrocatalytic performance for formic acid oxidation

Abstract

In this paper, the electrodeposition method is used to deposit dendritic Pd-CoO on the surface of Pd/PW₁₀V₂/rGO step by step to prepare a Pd-CoO/TMSPs/rGO composite. The composite was characterized via XRD, Raman, XPS, SEM, TEM and EDS. It can be proved that GO was reduced, Pd and CoO were partially alloyed, and a special dendritic morphology structure was formed. Moreover, the electrocatalytic properties for formic acid oxidation (FAO) were investigated using cyclic voltammetry (CV), chronoamperometry (i–t curves), CO stripping voltammetry and EIS. The results show that the special morphology of the Pd-based material and the addition of CoO change the electrical properties of the catalyst, enhance its chemical adsorption, and improve the electrocatalytic activity of Pd. In addition, the morphology of Pd changes from spherical to dendritic, which increases the utilization rate of the metal, and further improves the electrocatalytic stability and activity of FAO. The electrodeposited Pd-CoO/TMSPs/rGO is conducive to the fast transfer of electrons, which improves the electrocatalytic activity towards FAO. Furthermore, carbon monoxide is more easily oxidized to carbon dioxide on the prepared composite. Therefore, the dendritic Pd-CoO/TMSPs/rGO composite can be used as an efficient catalyst toward FAO. The synergistic effect of the composite between the highly active sites of Pd, the dendritic morphology, the anti-CO-poisoning ability of H₅PW₁₀V₂O₄₀ and the promotable oxidizability of CoO is the main reason for its excellent electrocatalytic activity.