Effect of Metal Substrate on Electrocatalytic Property of Palladium Nanowire Array for High Performance Ethanol Electro-Oxidation

Abstract

In this research, a high performance, ionomer-free electrocatalyst based on vertically aligned palladium (Pd) nanowire array was developed as an anode electrode toward ethanol oxidation reaction (EOR) in an alkaline environment. Using a one-step electrodeposition method, the Pd nanowires with controlled length were obtained by varying the electrodeposition current density and the synthesis time. Scanning electron microcopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray powder diffraction (XRD) were employed to characterize the morphology, chemical composition, and crystal structure of the Pd nanowires. The length effects of the nanowires, in the range of 0.8–4.5 μm, and various metal substrates, such as Ag, Cu, Ni, and Ti, were investigated for their electrochemical activities. The results demonstrated that Ag was the most active substrate to facilitate the ethanol oxidation reaction of the Pd nanowire array (NWA) electrocatalyst, which could be related to its good electrical conductivity. The stability test of the Pd NWA/Ag over time for EOR was also carried out, and the catalytic activity was recovered after the electrode was replaced with a new ethanol solution. Electrochemical impedance spectroscopy (EIS) measurements were performed to provide insights in the electron transfer resistance between the electrode and analyte. Gas chromatography and UV–vis spectroscopy were employed to measure the concentration of chemical species, which helped elucidate the overall reaction mechanism on the electrode surfaces.

Assembly of Alloyed PdCu Nanosheets and Their Electrocatalytic Oxidation of Ethanol

“…The ideal complete electrochemical oxidation reaction of ethanol in alkaline media is recognized as a 12-electron-transfer reaction (eqs ) (C 1 pathway), − limited by the difficulty of C–C breaking. In general, the EOR on the surface of the catalytic electrode shows a four-electron-transfer incomplete oxidation process to acetic acid (eqs and ) (C 2 pathway). , …”

Enhanced Electrocatalytic Activity of Alloyed Palladium–Lead Nanoparticles toward Electrooxidation of Ethanol

“…To study the effect of Pb doping on the catalysis of alcohol oxidation, a class of electrochemical experiments were conducted, and the EOR was chosen as a model to evaluate and compare the electrocatalytic activity of PdPb NPs, and each step of the elementary reaction can be analyzed during the CV process. ,− The CV properties of PdPb NPs and Pd/C were investigated in a 1.0 M KOH solution, as shown in Figure a, and typical peaks associated with the absorption and desorption of hydrogen were observed in the potential range between −0.85 and −0.65 V . Hydroxyl ions can adsorb onto the surface of the catalysts and the (Pd–OH ads ) is formed, followed by the oxidation from (Pd–OH ads ) to (Pd–O) during the forward scanning.…”

A high-performance Pt-based catalyst for the methanol oxidation reaction: effect of electrodeposition mode and cocatalyst on electrocatalytic activity

“…4(B)) became less linear, which indicates that the diffusion process is promoted and the overall reaction rate increases. 80 The respective Bode plots (insets of Fig. 4(B) and Fig.…”