An electrochemical method to prepare of Pd/Cu2O/MWCNT nanostructure as an anode electrocatalyst for alkaline direct ethanol fuel cells

This study reports an electrochemical method to fabrication of palladium nanoparticles (Pd NPs) promoted with cuprous oxide (Cu2O) supported on multi-walled carbon nanotube (Pd/Cu2O/MWCNT). First, Cu2O is electrodeposited on treated MWCNTs in the optimum deposition conditions. Then, the Pd nanostructure is electrochemically fabricated on Cu2O/MWCNT electrode by cycling the potential between +0.5 to −1.0 V in negative direction. The prepared electrodes are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). The electrocatalytic performance of Pd/Cu2O/MWCNT electrocatalyst for ethanol oxidation reaction (EOR) is investigated by cyclic voltammetric (CV), electrochemical impedance spectroscopy (EIS), and chronoamperometry (CA) measurements. The formation of the Pd/Cu2O/MWCNT is confirmed by EDX and XRD techniques. The onset potential of Pd/Cu2O/MWCNT shifts to negative values by 120 mV compared to the onset potential of Pd/MWCNT. Much higher If/Ib value is obtained for Pd/Cu2O/MWCNT compared to other Pd-based catalysts indicating Cu2O could significantly enhance the stability and CO poisoning tolerance of the Pd towards ethanol electrooxidation. The results revealed that the prepared Pd/Cu2O/MWCNT catalyst can be a promising anode catalyst for alkaline direct ethanol fuel cells.