Deposition of palladium-copper nanostructure on reduced graphene oxide by a simple method toward formic acid oxidation

Abstract

A simple and fast galvanic reduction method is applied to the preparation of Pd-Cu/rGO modified electrode. The preparation method includes reduction of deposited graphene oxide (GO) on the Glassy Carbon Electrode (GCE), and reduction of deposited CuCl2-PdCl2 on reduced graphene oxide. Both reduction steps are performed using 2% aqueous Zn/HCl solution. During the second step, palladium-copper bimetallic nanonetwork was created on reduced graphene oxide (rGO). To investigate the morphology, crystalline phases and chemical composition of the as-prepared catalyst, Field Emission Scanning Electron Microscopy (FESEM), Fourier-Transform Infrared (FTIR), X-ray Diffraction (XRD), Energy-Dispersive X-ray Spectroscopy (EDS), and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) were applied, respectively. Catalytic activity and stability of Pd-Cu/rGO were studied by cyclic voltammetry and chronoamperometry. The Pd-Cu nanocatalyst supported on reduced graphene oxide illustrates greatly increased electrocatalytic activities for formic acid oxidation (FOR) in an acid electrolyte. The current density (265 mA cm−2) and mass activity (3704 mA mg−1Pd) of Pd-Cu/rGO catalyst were higher by 4.7 and 2.07 times than that of Pd/C for the formic acid oxidation. Moreover, Pd-Cu/rGO catalyst represented improved stability during FOR than Pd/C.