Galvanic replacement of Pt by Cu to synthesize highly active and durable Pt@Cu/C anode as oxygen evolution reaction catalyst

Abstract

In this research, a two-step procedure was applied to prepare Pt/Cu/C titanium-supported anode as an oxygen evolution reaction (OER) catalyst. First, the copper nanoparticles with an average particle size of 20 nm were chemically reduced on carbon Vulcan powder (Cu/C). Then, galvanic replacement of Pt by Cu was performed by immersing Cu/C powder in a platinum solution. Finally, the catalyst ink was brushed over the activated titanium substrate using Pt/Cu/C powder and polyvinylidene difluoride (PVDF) in N-methyl-2-pyrrolidone (NMP) solvent. The effect of different factors, such as synthesis temperature and platinum loading on the catalytic properties of nanoparticles, including electrochemical surface area (ECSA), activity, stability, and durability for the OER, were evaluated by cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry, and consecutive CV. The results showed that the platinum loading level of 0.5 mg/cm2 and the synthesis temperature of 60 °C provide the best catalytic performance. Also, compared to the commercial electrodes of iridium oxide and ruthenium oxide with the same noble metal loading, higher activity is obtained for Pt/Cu/C electrode than the two mentioned electrodes. In addition, from a lifetime standpoint, the Pt/Cu/C electrode showed higher stability than the commercial ruthenium oxide electrode.