Electro-oxidation of Ethanol and Methanol on Pd/C, Pd/CNFs and Pd-Ru/CNFs Nanocatalysts in Alkaline Direct Alcohol Fuel Cell

Pd/C, Pd/CNFs and Pd-Ru/CNFs nanocomposite materials were utilized as anode nanocatalysts in low-temperature alkaline direct alcohol fuel cells. The palladium based nanocatalysts performance and stability were firmly relying upon the attributes of the carbon nanofibers (CNFs). CNFs were successfully synthesized employing a chemical vapour deposition method. The nanocatalysts were synthesized by dispersing Pd and Pd-Ru nanoparticles onto the CNFs surface using alcohol reduction method. The physical properties of the synthesized nanocatalysts were explored utilizing several techniques such as transmission electron microscope (TEM), scanning electron microscope-Energy dispersive x-ray (SEM-EDX), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS) and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and confirmed successful synthesis of Pd/C, Pd/CNFs and Pd-Ru/CNFs nanocomposite. TEM showed that Pd and Ru nanoparticles were uniformly dispersed on the CNFs support surface. ICP-OES determined the palladium and ruthenium concentration in Pd/C, Pd/CNFs and Pd-Ru/CNFs nanocatalysts to be Pd (7.67 %), Pd (7.74 %), Pd (7.82 %) and Ru (3.22 %) respectively. The three prepared nanocatalysts were evaluated by cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) in the evaluation of ethanol and methanol oxidation reactions. CV, CA and EIS experiments of Pd-Ru/CNFs nanocatalyst displayed superior activity towards alcohol oxidation reaction in alkaline conditions than Pd/CNFs and commercial Pd/C nanocatalysts.